2024 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

This topic was prioritized for review by the BLS Task Force because it had not been reviewed since 2019.^4,5 Since the last SysRev of this topic,⁶ the task force was concerned that the practice of moving patients from the bed to the floor to improve the quality of CPR could delay CPR; thus, it was considered timely to update the SysRev completed for the 2020 CoSTR.^4,5 The SysRev was registered before initiation (International Prospective Register of Systematic Reviews [PROSPERO] CRD42017080475).⁷ The full online CoSTR can be found on the ILCOR website.⁸

In addition to the 11 manikin simulation RCTs^9–19 identified in the previous review,⁶ we identified 1 small observational study²⁰ and 6 additional manikin RCTs^21–26 addressing this population, intervention, comparator, outcome, study design, and time frame (PICOST) question. The overall certainty of evidence was rated as very low to low due to risk of bias and serious indirectness. No studies reported patient outcomes. The included studies were grouped by surfaces studied: backboard versus hospital mattress, floor versus hospital mattress, floor versus firm home mattress, and floor versus other surface types. The small observational study that compared a backboard with a hospital mattress used a single accelerometer for measurement, and the results were considered unreliable.²⁰ Results of the meta-analysis of data from the manikin simulation studies are given in Table 1.

We suggest performing chest compressions on a firm surface when possible (weak recommendation, very low–certainty evidence).

During in-hospital cardiac arrest, we suggest, where a bed has a CPR mode which increases mattress stiffness, it should be activated (weak recommendation, very low–certainty of evidence).

During in-hospital cardiac arrest, we suggest against moving a patient from a bed to floor to improve chest compression depth (weak recommendation, very low–certainty of evidence).

During in-hospital cardiac arrest, we suggest in favor of either a backboard or no-backboard strategy, to improve chest compression depth (conditional recommendation, very low–certainty of evidence).^4,5

We suggest performing chest compressions on a firm surface when this is practical and does not significantly delay the start of chest compressions (weak recommendation, very low–certainty evidence).

We suggest activation of the CPR mode to increase mattress stiffness if available for in-hospital cardiac arrest (good practice statement).

For health care systems that have already incorporated backboards into routine use during resuscitations, the evidence was considered insufficient to suggest against their continued use (weak recommendation, very low–certainty of evidence).

For health care systems that have not introduced backboards, the limited improvement in compression depth and uncertainty about harms seemed insufficient to justify the costs of purchasing backboards and training staff in their use (weak recommendation, very low–certainty of evidence).

The complete evidence-to-decision framework is provided in Appendix A.

When performing chest compressions on a patient lying on a mattress, the force of the chest compressions is dissipated through the compression of the chest and compression of the surface beneath the patient. Mattress compression can be as high as 57% of total compression depth, with greater compression seen in softer mattresses.^27–29 This can lead to reduced spinal-sternal displacement and a reduction in effective chest compression depth. It is known that effective compression depths can be achieved on soft surfaces if the CPR provider increases overall compression depth to compensate for mattress compression.^30–33 CPR feedback devices that account for mattress compression (eg, the use of dual, and not single, accelerometers or increasing compression depth targets) can help CPR providers to ensure adequate compression depth when CPR is performed on a mattress.^11,33–35

In making these recommendations, the task force considered the importance of high-quality chest compressions and minimizing delays to the initiation of CPR and the lack of human data, including patient outcomes. Within the limitations of manikin studies, the available evidence indicates that using a backboard on a hospital mattress provides only a marginal depth benefit that is unlikely to be clinically significant. In considering whether to transfer a patient to the floor to improve compression depth, the task force considered the risks of harm (eg, interruption in CPR, risk of losing vascular access) to the patient and resuscitation team outweighed any small improvement in chest compression depth. The addition of 2 studies simulating out-of-hospital settings (where beds may be softer) and one where the CPR provider may be a single untrained rescuer led the task force to broaden the recommendations to include OHCA. The task force felt the indirect evidence on backboards was not sufficient to have backboards removed where they are currently used. However, users should be aware that mattress stiffness and backboard size and orientation influence the backboard’s effectiveness.^36–39

The 2020 CoSTR on dispatcher-assisted diagnosis of cardiac arrest recommended that dispatch centers look for ways to optimize sensitivity of recognition of cardiac arrest.^4,5 These interventions have not been reviewed by ILCOR before. A ScopRev was conducted to understand factors related to DA recognition and to review the current state of evidence for interventions aiming to optimize timely recognition to inform the development of a PICOST for a SysRev.⁴⁰ The full online CoSTR can be found on the ILCOR website.⁴¹

This ScopRev identified 60 relevant articles.^42–101 The included articles described 4 major categories and 18 subcategories: 2 major categories and 11 subcategories relate to factors found to influence DA recognition, and 2 major categories and 7 subcategories were interventions aiming to improve DA recognition (Table 2). The detailed findings within each theme are summarized in the full CoSTR on the ILCOR website.⁴¹

The 2020 SysRev recommends CPR instructions be provided by dispatchers during the emergency call.^4,5 Although the certainty of evidence was rated as very low at that time, dispatcher-assisted CPR (DA-CPR) has been implemented widely,^102–105 and the task force was aware of new evidence examining interventions aiming to optimize DA-CPR. A ScopRev was conducted to map this evidence and determine if it was sufficient to warrant a new SysRev of interventions to improve DA-CPR.¹⁰⁶ Studies comparing compression-only CPR with standard CPR were excluded as this topic is covered in a separate ILCOR PICOST.^107,108 The full online CoSTR can be found on the ILCOR website.¹⁰⁹

Thirty-one studies were included in this ScopRev: One was a nonrandomized implementation trial,¹¹⁰ 16 were simulation studies (15 RCTs,^111–125 1 nonrandomized comparison¹²⁶), and 12 were observational studies reviewing real-world OHCAs from registries or collected data^{80,83,126–135} or emergency call review.¹³⁶ Two included studies used qualitative¹³⁷ and mixed methods.¹³⁸ Only 1 study focused on pediatric cardiac arrest.¹¹⁷ Complete details of the studies and findings are reported in the full CoSTR on the ILCOR website.

The interventions examined were advanced dispatcher training (n=3),^127–129 centralization of the dispatch center (n=2),^130,131 use of metronome or varied metronome rates (n=2),^111,112 change in CPR sequence and compression ratio (n=1)¹³² an animated audiovisual recording (n=1),¹¹³ prerecorded instructions compared with conversational live instructions (n=1)¹¹⁴ implementation of novel DA-CPR protocols (n=4)^{80,83,110,115} changes in terminology about compressions (n=6; 1 pediatric), ^{116–118,126,133,136} inclusion of “undress patient” instructions (n=1),¹¹⁹ verbal encouragement (n=1),¹²⁵ and use of video at the scene (n=9).^{120–124,134,135,137,138}

The implementation of novel DA-CPR protocols, prerecorded instructions, centralized dispatch, advanced dispatcher training, use of metronomes and varying metronome rates and instructions to undress the patient all have <3 articles published, and therefore, we are unable to make any comment on their effectiveness at this point.

The studies that focus on simplifying the compression instruction language (ie, “Push as hard as you can” versus “Push ≈2 inches/5 cm”) suggest an improvement in the quality of CPR.^{117,118,126,133} The studies that examined adding video to the emergency call, compared with audio-only calls, suggest an improvement in CPR practice (eg, hand positioning) and quality (eg, compression depth and rate).^{120–124,135}

The task force discussed the review findings and noted the following:

Based on this ScopRev, there is insufficient evidence to pursue a new SysRev on this topic.

Bystander use of AEDs is associated with high survival rates from OHCA,^139,140 but its use is currently infrequent.¹⁴¹ This topic was selected for review by the BLS Task Force because of the widespread use of dispatch instructions for the retrieval and use of an AED^105,142 and the need to optimize systems to improve the public’s AED use.^143,144 Although there is no existing ILCOR treatment recommendation related to dispatcher-assisted AED retrieval, the task force decided the current evidence required a ScopRev to fully explore the scope of the topic. Studies using drone delivery were excluded from this review because this evidence was examined in the 2023 CoSTR publication.¹⁴⁶ The full online CoSTR can be found on the ILCOR website.¹⁴⁷

Sixteen studies were included in this ScopRev: 5 observational studies reviewing real-world OHCAs^148–152 and 11 simulation studies (6 RCTs,^153–158 1 nonrandomized trial,¹³⁸ and 4 observational^159–162).

There were no studies that examined patient outcomes. One observational study did report improvement in survival with favorable neurological outcome in 1132 (of 1606) OHCAs when a DA-CPR protocol included instructions to retrieve an AED, but the relative contribution of the dispatcher-assisted AED instruction could not be determined from the data provided.¹⁵⁰

In systems using dispatcher-assisted AED retrieval and use, 5 observational studies reported low rates of AED retrieval (0.8%–5.8%),^148,149,151 pad application (0.4%–1.7%),^149,151,152 and shocks delivered (2.4%–11%).^148,150 In one study, rates of bystander defibrillation were greater with dispatcher instructions to retrieve an AED, compared with cases where no instructions were given (11% versus 5%, unadjusted P<0.001).¹⁵⁰ Another observational study reported confusion and delays in the emergency call after a 3-part instruction to retrieve an AED.¹⁴⁸ Callers often had to ask the dispatcher to repeat the instruction, or they asked clarifying questions.

In simulation studies, time to first shock, when measured from the time the AED arrived, was longer when dispatcher assistance was provided than when there was no assistance.^153,154 However, when time to retrieve an AED was factored in, time to first shock was shorter.^156,157

AED competence scores were consistently higher with dispatcher assistance (or an analogous form of instruction).^{138,153,154,158,162} In a simulation study, the use of video instruction enabled the correction of pad placement, which initially was done incorrectly by most bystanders.¹⁶² In another study the use of mobile phone video resulted in better performance than verbal instruction alone,¹⁵³ but a second study demonstrated no difference.¹³⁸ The use of prerecorded video instruction was inferior to real-time (verbal) dispatcher instruction.¹⁵⁸ In 1 study, dispatchers facilitated the application of an AED in 5 out of 6 cases when the AED had been brought to the (simulated) patient’s side, but the study participant did not attempt to use it unprompted.¹⁶⁰

The studies reviewed in the present ScopRev suggest there is currently insufficient evidence to pursue a new SysRev on this topic. There were no previous treatment recommendations on this topic. Given the widespread adoption of this intervention and interest in this topic, the task force considered the available evidence and developed the following good practice statements.

EMS implementing dispatcher-assisted public-access AED systems should monitor and evaluate the effectiveness of their system (good practice statement).

Once a cardiac arrest is recognized during the emergency call and CPR has been started, dispatchers should ask if there is an AED (or defibrillator) immediately available at the scene and ask the caller to update them when one arrives (good practice statement).

If an AED is not immediately available and if there is more than 1 rescuer present, dispatchers should offer instructions to locate and retrieve an AED. Retrieval instructions should be supported, where resources allow, by up-to-date registries about public-access AED locations and accessibility (good practice statement).

Once an AED is available, dispatchers should offer instructions on its use (good practice statement).

CPR feedback devices are intended to improve patient outcomes through improving the quality of CPR. The 2020 CoSTR on feedback for CPR quality recommended the use of real-time audiovisual feedback and prompt devices during CPR when used as part of a comprehensive quality improvement program.^4,5 There were challenges with the 2020 ILCOR review due to the exclusion of many studies because they combined the evaluation of feedback with other quality improvement activities (eg, debriefing). The task force decided to perform a ScopRev to understand if the wider literature, including studies with other interventions, may provide further insights into the effectiveness of feedback and improve the existing PICOST question.¹⁶⁵ Additionally, the task force concluded that this review should focus on the provision of CPR by health professionals responding in a professional capacity, rather than by bystanders or lay responders. The detailed results are provided on the ILCOR website.¹⁶⁶

Of the 55 studies included, we identified 10 SysRevs,^167–176 5 RCTs,^177–181 37 observational studies,^20,182–216 2 case series,^217,218 and 1 commentary.²¹⁹ The patients included varied widely between studies. Only 3 studies included children,^210,212,220 and most of the evidence consisted of before-and-after studies.

The use of metronomes was examined in 1 SysRev from 2014¹⁷⁶ and 6 observational studies (3 OHCA and 3 IHCA).^182–187 This evidence suggests an associated improvement in CPR quality, but there are few data on patient outcomes and what outcome data are reported are not adjusted for confounding (Table 3).

By including a wider range of published studies and studies examining audiovisual feedback with other system improvements, we identified 9 SysRevs,^167–175 5 RCTs,^177–181 31 observational studies,^{20,188–216,220} and 2 case series.^217,218 Evidence examining key outcomes with a non-feedback comparator group suggests improved CPR quality, but most studies reporting improved patient outcomes beyond ROSC included other interventions, such as high-performance CPR and postevent debriefing (Table 4). This evidence aligns with ILCOR’s current treatment recommendation that feedback devices should be used as part of a comprehensive quality improvement program.^4,5

We suggest the use of real-time audiovisual feedback and prompt devices during CPR in clinical practice as part of a comprehensive quality improvement program for cardiac arrest designed to ensure high-quality CPR delivery and resuscitation care across resuscitation systems (weak recommendation, very low–certainty evidence).

We suggest against the use of real-time audiovisual feedback and prompt devices in isolation (ie, not part of a comprehensive quality improvement program, weak recommendation, very low–certainty evidence).

Early defibrillation is associated with a large increase in survival from OHCA.^221–224 If defibrillation occurs within 3 to 5 minutes of collapse, survival rates as high as 50% to 70% have been reported.^223,224 EMS response times rarely enable delivery of defibrillation in such a short time.²²⁵ Recently, several companies have started advertising “ultraportable” or “pocket” AEDs for personal use or equipping community volunteer responders to improve AED availability. These devices may be limited in the number and the energy of the shocks they deliver (eg, restricted to up to 20 shocks and a maximum of 85 J). This topic has not been reviewed before, and given the interest in these devices, the task force thought a review of their effectiveness in practice was timely.^225a The detailed results are provided on the ILCOR website.²²⁶

This review included 3 studies: a medico-economic simulation study,²²⁷ a study protocol of a cluster RCT,²²⁸ and an abstract with preliminary results of that cluster RCT.²²⁹ Key findings from these studies are summarized in Table 5.

There is currently insufficient evidence to recommend progression to a formal SysRev. Given the proliferation of these devices, the task force issues a good practice statement requesting research.

There is currently insufficient evidence on the clinical effectiveness of ultraportable or pocket AEDs to make a treatment recommendation.

Topics evaluated with EvUps are summarized in Table 6. The complete EvUps are provided in Appendix B.

This review was conducted by the ALS Task Force in collaboration with the BLS Task Force. Oxygenation and ventilation are important components of post–cardiac arrest management. This topic was last updated with a SysRev for the 2020 CoSTR (PROSPERO registration CRD42022371007).^230–232 Since the last review of this topic, the task forces were aware of new clinical trials, prompting an update of the SysRev. The complete CoSTR can be found online.²³³

Five new RCTs including adult patients were identified.^234–238 These studies add to the previous SysRev, which included 7 RCTs.^{231,239–245} Studies used various specific oxygen and carbon dioxide strategies or targets, as defined in Table 7.

Key results for both oxygen and carbon dioxide comparisons are presented in Table 8 and Table 9. Overall, there was no consistent evidence of benefit or harm from the different oxygen and carbon dioxide strategies investigated.

We suggest the use of 100% inspired oxygen until the arterial oxygen saturation or the partial pressure of arterial oxygen can be measured reliably in adults with ROSC after cardiac arrest in any setting (weak recommendation, very low–certainty evidence).

We recommend avoiding hypoxemia in adults with ROSC after cardiac arrest in any setting (strong recommendation, very low–certainty evidence).

We suggest avoiding hyperoxemia in adults with ROSC after cardiac arrest in any setting (weak recommendation, low-certainty evidence).

There is insufficient evidence to suggest for or against targeting mild hypercapnia compared with normocapnia in adults with ROSC after cardiac arrest.

We suggest against routinely targeting hypocapnia in adults with ROSC after cardiac arrest (weak recommendation, low-certainty evidence).^230,232

The complete evidence-to-decision table is provided in Appendix A.

The topic of hemodynamic goals after cardiac arrest was previously reviewed by the ALS Task Force in 2015,^253,254 and an EvUp was conducted in 2020.^230,232 In the previous recommendation, consideration of hemodynamic goals was suggested, but there was insufficient evidence to recommend a specific target. New RCTs have been published on this topic, and the task force decided a SysRev was warranted. A recently published SysRev with individual patient data meta-analysis, which included a meta-analysis of the effect of targeting a mean arterial pressure (MAP) higher or lower than 70 mm Hg, was identified; this review was deemed of sufficient quality to be used for adolopment.²⁵⁵ The complete CoSTR can be found online.²⁵⁶

The SysRev identified 4 RCTs of 1065 patients comparing lower and higher MAP targets after ROSC.^257–260 The included RCTs provided low-certainty evidence (downgraded for risk of bias and indirectness) of no benefit from a higher MAP compared with a lower MAP target for the critical outcomes of mortality at 180 days (RR, 1.08 [95% CI, 0.92–1.26]) and good functional outcome at 180 days (RR, 0.99 [95% CI, 0.84–1.16]). Similarly, there was no benefit for the outcomes of ICU mortality (RR, 1.09 [95% CI, 0.81–1.46]) or new arrhythmia resulting in hemodynamic compromise or cardiac arrest during ICU stay (RR, 1.04 [95% CI, 0.77–1.40]).

We suggest hemodynamic goals (eg, MAP, systolic blood pressure) be considered during postresuscitation care and as part of any bundle of postresuscitation interventions (weak recommendation, low-certainty evidence).

There is insufficient evidence to recommend specific hemodynamic goals; such goals should be considered on an individual patient basis and are likely to be influenced by post–cardiac arrest status and pre-existing comorbidities (weak recommendation, low-certainty evidence).^253,254

There is insufficient scientific evidence to recommend a specific blood pressure goal after cardiac arrest. Therefore, we suggest a mean arterial blood pressure of at least 60 to 65 mm Hg in patients after out-of-hospital (moderate-certainty to low-certainty evidence) and IHCA (low-certainty to very low–certainty evidence).

The complete evidence-to-decision table is provided in Appendix A.

In making these updated recommendations, the ALS Task Force considered the following:

Since publication of the prior SysRev,²⁶⁵ the task force has been aware of new clinical trials examining temperature control in comatose post–cardiac arrest patients and, therefore, updated the SysRev (PROSPERO registration of original review CRD42020217954). The SysRev covered the following 6 different aspects of temperature management: (1) use of hypothermic temperature control, (2) timing, (3) specific temperature, (4) duration of temperature control, (5) method of temperature control, and (6) rate of rewarming. The full CoSTR can be found online.²⁶⁶

We suggest actively preventing fever by targeting a temperature ≤37.5 °C for patients who remain comatose after ROSC from cardiac arrest (weak recommendation, low-certainty evidence).

Whether subpopulations of cardiac arrest patients may benefit from targeting hypothermia at 32 °C to 34 °C remains uncertain.

Comatose patients with mild hypothermia after ROSC should not be actively warmed to achieve normothermia (good practice statement).

We recommend against the routine use of prehospital cooling with rapid infusion of large volumes of cold intravenous fluid immediately after ROSC (strong recommendation, moderate-certainty evidence).

We suggest surface or endovascular temperature control techniques when temperature control is used in comatose patients after ROSC (weak recommendation, low-certainty evidence).

When a cooling device is used, we suggest using a temperature control device that includes a feedback system based on continuous temperature monitoring to maintain the target temperature (good practice statement).

We suggest active prevention of fever for at least 72 hours in post–cardiac arrest patients who remain comatose (good practice statement).^283,284

We suggest active prevention of fever for 36 to 72 hours in post–cardiac arrest patients who remain comatose (good practice statement).

The complete evidence-to-decision table is provided in Appendix A.

This topic was last updated in 2020.^230,232 This was a nodal SysRev between the ALS and Pediatric Life Support Task Forces based on the knowledge of new evidence examining the treatment of seizures after cardiac arrest. The nodal review included both adults and children. Readers should refer to the pediatric life support section for pediatric-specific recommendations on this topic. The SysRev was registered on PROSPERO (CRD42023460746 and CRD42023463581), and the full CoSTR can be found online.²⁸⁷

We suggest against seizure prophylaxis in adult post–cardiac arrest survivors (weak recommendation, very low–certainty evidence).

We suggest treatment of seizures in adult post–cardiac arrest survivors (weak recommendation, very low–certainty evidence).^230,232

We suggest against the use of prophylactic antiseizure medication in post–cardiac arrest adults (weak recommendation, very low–certainty evidence).

We suggest treatment of clinically apparent and electrographic (EEG) seizures in post–cardiac arrest adults (good practice statement).

We suggest treatment of rhythmic and periodic EEG patterns that are on the ictal-interictal continuum in comatose post–cardiac arrest adults (weak recommendation, low-certainty evidence).

The complete evidence-to-decision table is provided in Appendix A.

The task force was aware of new research published on the use of ECPR, and the decision was made to update our previous SysRev (PROSPERO registration CRD42022341077).^295,296 For evidence related to pediatric cardiac arrest, refer to the Pediatric Life Support section of this summary. The full CoSTR can be found online.²⁹⁷

A single new RCT was identified.²⁹⁸ This adds to the 3 RCTs identified in the previous review.^{296,299–301} Given the existence of 4 RCTs and the critical risk of bias of the observational studies identified in prior reviews, only evidence from RCTs was considered.

The overall certainty of evidence was rated as low for OHCA and as very low for IHCA (downgraded further because all evidence was in OHCA) for all outcomes. Because of a high degree of heterogeneity between the randomized trials, no meta-analyses were performed. Key results are summarized in Table 12.

We suggest that ECPR may be considered as a rescue therapy for selected adults with out-of-hospital cardiac arrest when conventional cardiopulmonary resuscitation is failing to restore spontaneous circulation in settings where this can be implemented (weak recommendation, low-certainty evidence).

We suggest ECPR may be considered as a rescue therapy for selected adults with in-hospital cardiac arrest when conventional cardiopulmonary resuscitation is failing to restore spontaneous circulation in settings where this can be implemented (weak recommendation, very low–certainty evidence).

The complete evidence-to-decision table is provided in Appendix A.

Cardiac arrest during pregnancy is a rare but catastrophic event. Physiologic changes during pregnancy and concerns about both maternal and fetal survival bring additional considerations to resuscitation of a pregnant patient. The task force was aware that the evidence available was insufficient for a SysRev and meta-analysis to be possible but thought a review of this topic was a high priority, and this ScopRev was thus completed. The full report of this ScopRev, including detailed tables describing the individual studies, can be found online.³⁰²

This ScopRev identified 8 heterogeneous studies describing several interventions for cardiac arrest during pregnancy.^303–310 The studies are substantially limited by lack of granularity, small sample sizes, indirect measures of interventional effects, and high degrees of bias and confounding.

Studies are described in detail in the data tables in the online ScopRev.³⁰² The studies identified concentrated on 3 interventions: (1) left-lateral uterine displacement with supine positioning for resuscitation, (2) perimortem or resuscitative delivery, and (3) extracorporeal life support.

Indirect data from a porcine model demonstrated significantly higher coronary perfusion pressures during resuscitation with supine positioning with left-lateral uterine displacement compared with left-lateral tilt positioning (perfusion pressure of 20 mm Hg compared with 5 mm Hg, P<0.05).³⁰⁵ Five observational studies reported data supporting performing perimortem cesarean or resuscitative delivery when ROSC does not occur early during resuscitation of cardiac arrest in a pregnant person with a uterine size ≥20 weeks’ gestation.^306–310 The median time from collapse to cesarean delivery in survivors and nonsurvivors varied across studies, but shorter times from arrest to delivery were associated with improved maternal and neonatal outcomes. Two studies suggested that extracorporeal life support may improve pregnancy and peripartum outcomes for both the pregnant person and fetus in the setting of cardiac arrest, despite the potential of bleeding and clotting complications.^303,304

The task force prioritized this topic because of the ongoing burden of mortality during pregnancy (estimated at 287 000 deaths globally in 2020, with mortality increasing in some countries, such as the United States).^311,312 The prevalence of cardiac arrest during hospitalizations for delivery in the United States from 2017 to 2019 rose to 1/9000, previously reported as 1/12 000 in 2014 using the US National Inpatient Sample database.³¹³ Cardiac arrest is the final common pathway of several pathophysiologic conditions leading to death during pregnancy, including hemorrhage, cardiomyopathy, hypertensive complications, embolic events, and sepsis. Management of cardiac arrest is complex because it requires accommodation of the physiological changes of pregnancy. Randomized trials are challenging to perform during pregnancy, and the evidence on this topic is limited. For these reasons, the task force decided to summarize the emerging research and identify specific knowledge gaps. The limited data did not support a full SysRev or making any changes to existing treatment recommendations, but 2 good practice statements were made.

We suggest delivery of the fetus by perimortem cesarean delivery for women in cardiac arrest in the second half of pregnancy (weak recommendation, very low–certainty evidence).

There is insufficient evidence to define a specific time interval by which delivery should begin.

High-quality usual resuscitation care and therapeutic interventions that target the most likely cause(s) of cardiac arrest remain important in this population.

There is insufficient evidence to make a recommendation about the use of left-lateral tilt or uterine displacement during CPR in the pregnant patient.

ECPR may be considered as a rescue therapy for selected cardiac arrest patients during pregnancy or in the postpartum period when conventional CPR fails and in settings in which it can be implemented (good practice statement).

This good practice statement does not replace the ALS treatment recommendation for use of ECPR in general.

Institution readiness and resuscitation education are required to accommodate the unique physiologic challenges of cardiac arrest during pregnancy (good practice statement).

This topic was selected for review by the ALS Task Force due to ongoing uncertainty concerning optimal strategies for emergency airway management in cardiac arrest when standard approaches to basic and advanced airway management fail. The full report of this ScopRev³¹⁴ can be found online.³¹⁵

Our search identified a single RCT³¹⁶ and 68 observational studies from prehospital, in-hospital, and military settings.^317–384 No studies specifically focused on cardiac arrest.

The RCT compared emergency cricothyrotomy and emergency percutaneous dilatational tracheostomy in 169 patients (9 with cardiac arrest) with failed airway management in the emergency department.³¹⁶ The success rate of percutaneous cricothyrotomy (95.3%) was similar to that of percutaneous dilatational tracheostomy (97.6%; P=0.45).

The observational studies documented a median 11.4 front-of-neck access attempts per study (interquartile range [IQR], 2.9-31.5). Most studies were trauma specific or a mix of trauma and medical emergencies and occurred in a mix of prehospital, in-hospital, and military settings. The most common emergency front-of-neck airway intervention was surgical cricothyroidotomy.

Incidence of front-of-neck airway access attempts varied markedly across studies, from 0.06 to 436 attempts per 1000 patients. The variability was predominantly driven by the denominator chosen in each study (eg, all intubation attempts or all cases of failed intubation). Success rates were typically high, with most studies reporting success rates of >70%. Outcomes varied markedly across studies. In cardiac arrest patients, rates of ROSC ranged from 0% to 64%. The evidence on complications was challenging to interpret because reporting was inconsistent.

The task force discussed the review findings and noted the following:

In adults in cardiac arrest, when standard airway management strategies (eg, oropharyngeal airway and bag-mask, supraglottic airway, or tracheal tube) have failed, it is reasonable for appropriately trained rescuers to attempt front-of-neck airway access using a cricothyroidotomy technique (good practice statement).

ALS topics reviewed by EvUps are summarized in Table 13.

Determining the optimal BP targets in infants and children after cardiac arrest after ROSC, or after return of circulation (ROC) on mechanical support, poses a significant challenge due to lack of evidence. Clinical practice in this area is based on a few pediatric studies, extrapolation from studies conducted in adults, or expert consensus recommendations. While individual studies in infants and children suggest there is an association between hypotension post-ROSC or post-ROC and poor outcomes, these studies are small and it is unclear if the association is causal or a surrogate marker of more severe postresuscitation syndrome. To answer this knowledge gap, a systematic review aimed to evaluate the literature on the effects of BP targets on outcomes post-ROSC/ROC in infants and children (PROSPERO registration CRD42023483865). The full CoSTR can be found online.³⁸⁵

Six studies were identified.^387–392 All 6 were nonrandomized observational cohort studies, with 5 being secondary analyses. We identified significant variation in BP target definitions (eg, systolic, mean, and diastolic BP and >5th, >10th, and >50th percentile for age) and time frames for measurement (<20 minutes, 0–6 hours, within 24 hours, and 0–72 hours). In our final analysis, we included 4 studies^{388,389,391,392} examining the BP targets of systolic BP >5th percentile for age compared with systolic BP ≤5th percentile within the first 6 hours after ROC. One study was not included in our analysis because only diastolic BP targets were reported.³⁹⁰ The pooled sample included 463/930 (49.8%) patients after IHCA and 467/930 (50.2%) after OHCA. We also included 1 study³⁸⁷ that enrolled 693 infants and children after IHCA (excluding patients who required extracorporeal life support [ECLS]). This study compared systolic BP >10th percentile with systolic BP ≤10th percentile within the first 6 hours after ROC. The systolic BP cutoff at the 10th percentile was generated from receiver operator characteristic curves and spline curves created from the study data.

Results from included pediatric studies are included in Table 14. A random effects model was chosen for meta-analysis to better account for study heterogeneity.

We recommend that for infants and children after ROSC, parenteral fluids and/or inotropes or vasopressors should be used to maintain a systolic blood pressure of at least greater than the fifth percentile for age (strong recommendation, very low–certainty evidence).³⁹³

We suggest in infants and children with return of circulation after an IHCA or OHCA that a systolic BP >10th percentile for age should be targeted (weak recommendation, very low–certainty evidence).

The complete evidence-to-decision table is provided in Appendix A.

Cardiac arrest in children is relatively uncommon and has a very high mortality rate, with hypoxic-ischemic brain injury being a common cause of death. Seizures including suspected clinical, electroclinical, and electrographic seizures with EEG correlation are common manifestations of post–cardiac arrest brain injury in children, with an incidence of ≈10% to 40%.^394–396 Seizures and abnormalities on EEG post–cardiac arrest are associated with poor neurologic outcome in children.^396–399 It is unclear if prophylactic antiseizure medication to prevent seizures or treatment of seizures when they are identified improves outcome. There are no existing ILCOR recommendations for children, and this SysRev was thus undertaken (PROSPERO registrations CRD42023460746 and CRD42023463581). The full CoSTR can be found online.⁴⁰⁰

We suggest against the routine use of prophylactic antiseizure medication in children post–cardiac arrest (good practice statement).

The complete evidence-to-decision table is provided in Appendix A.

Airway management is vital in pediatric resuscitation, especially since respiratory conditions are frequently the primary cause of pediatric cardiac arrest. Maintaining an open airway and delivering sustained effective ventilations using a bag-mask device can be difficult, even in skilled hands. Placement of an advanced airway device, such as a supraglottic airway (SGA) or tracheal tube, may facilitate more effective oxygenation and ventilation than bag-mask ventilation (BMV). Both require skilled personnel, and the time taken to perform either procedure may interfere with other vital components of resuscitation (eg, chest compressions).

Since the last review of this topic,^409,409a the PLS Task Force was aware of new data, prompting this updated SysRev (PROSPERO registration CRD42023482459). The full CoSTR can be found online.⁴¹⁰

The PLS Task Force reviewed the evidence for the following comparisons: tracheal intubation (TI) compared with BMV, SGA compared with BMV, and TI compared with SGA during pediatric cardiac arrest.

Nineteen studies were included. Only 1 study provided clinical trial data.⁴¹¹ Five studies provided propensity-adjusted cohort data.^412–416 Nine other studies provided retrospective cohort data amenable to meta-analysis.^417–425 Four studies provided retrospective cohort data in adjusted form only, not amenable to meta-analysis.^426–429 One study⁴³⁰ that was included in the original SysRev⁴⁰⁹ was excluded from this updated SysRev because it overlapped with a newer study.⁴¹⁶ Summative results from 15 of the studies are included in Table 16; the 4 cohort studies with results not amenable to meta-analysis were excluded.

A random effects model was chosen for meta-analysis to better account for study heterogeneity. The results suggest that resuscitation with TI is not superior to BMV-based resuscitation for cardiac arrest in children for the critically important outcomes of survival with favorable neurological outcome and survival to hospital discharge (with low to very low certainty). Some very low–certainty evidence suggests the use of TI may be associated with harm.

We suggest the use of BMV rather than TI or SGA in the management of children during cardiac arrest in the out-of-hospital setting (weak recommendation, very low–certainty evidence).

There is insufficient evidence to support any recommendation about the use of TI or SGA in the management of children with cardiac arrest in the in-hospital setting.^409a

We suggest the use of bag-mask ventilation rather than tracheal intubation or supraglottic airway in the management of children during cardiac arrest in the out-of-hospital setting (weak recommendation, very low–certainty evidence).

There is insufficient quality evidence to support any recommendation for or against the use of the bag-mask ventilation compared with tracheal intubation or supraglottic airway for in-hospital cardiac arrest.

The main goal of cardiopulmonary resuscitation is effective ventilation and oxygenation, by whatever means, without compromising the quality of chest compressions. We suggest that clinicians consider transitioning to an advanced airway intervention (supraglottic airway or tracheal intubation) when the team has sufficient expertise, resources, and equipment to enable placement to occur with minimal interruptions to chest compressions or when bag-valve-mask is not providing adequate oxygenation and ventilation (good practice statement).

The complete evidence-to-decision table is provided in Appendix A.

Ventilation is a major component of CPR for children and infants in cardiac arrest. During CPR, an adequate ventilation rate is an important element of ventilation.^432,433 However, the appropriate ventilatory rate for children and infants during CPR remains a topic of ongoing debate and investigation.⁴³⁴ In 2010, the PLS Task Force reviewed the evidence about optimal minute ventilation (product of tidal volume and respiratory rate per minute) after the placement of an advanced airway during CPR in infants or children.⁴³² The minute ventilation recommended in the 2010 CoSTR was based on expert consensus. In 2020, an EvUp was completed to identify any evidence published after 2010 that might indicate the need for a new SysRev. The EvUp identified a single-center observational article that reported an association between ventilatory rate during IHCA >12 to 20 breaths per minute and improved outcomes.⁴³⁵ Since this EvUp, the task force was aware of new evidence that led the task force to conduct a SysRev (PROSPERO registration CRD42023480925). The full CoSTR can be found online.⁴³⁶

No studies were identified that compared the ventilatory rate of 8 to 10 breaths per minute with any other specific ventilatory rate.

After placement of a secure airway, avoid hyperventilation of infants and children during resuscitation from cardiac arrest, whether asphyxial or arrhythmic in origin. A reduction in minute ventilation to less than baseline for age is reasonable to provide sufficient ventilation to maintain adequate ventilation-to-perfusion ratio during CPR while avoiding the harmful effects of hyperventilation. There are insufficient data to identify the optimal tidal volume or respiratory rate.⁴³⁵

There is currently no supporting evidence to make a treatment recommendation on a specific ventilatory rate in pediatric cardiopulmonary resuscitation with an advanced airway.

For cardiac arrest that occurs with an advanced airway in place, the use of ventilatory rates >10 breaths per minute may be reasonable. The PLS Task Force suggests using ventilatory rates close to age-appropriate respiratory rates with avoidance of hypoventilation and hyperventilation (good practice statement).

This topic, with a new PICOST, was chosen by the PLS Task Force with input from the Neonatal Life Support Task Force because of the concern that children with pulmonary hypertension who are hospitalized are reported to be at higher risk of death after a cardiopulmonary arrest.⁴³⁷

In 2015, the American Heart Association and the American Thoracic Society published a guideline on the management of pediatric pulmonary hypertension.⁴³⁸ In 2018, the American Heart Association published a statement on the management of CPR in infants and children with cardiac disease that included a section on pulmonary hypertension.⁴³⁹ In 2018, the American Heart Association published a statement on right-sided heart failure and its management, but this statement focused on adults and did not include content for children.⁴⁴⁰ The 2019 ILCOR EvUps provided guidance on the acute treatment of pulmonary hypertension.

Faced with these children at high risk of cardiopulmonary arrest, we formulated the new PICOST and conducted a ScopRev to better understand if evidence for new specific therapies to treat cardiopulmonary arrest had been published. The full report of this ScopRev can be found online.⁴⁴¹

We included 19 studies in the ScopRev; 16 provided foundational background literature on the acute management of children with pulmonary hypertension,^{437–439,442–454} and 3 presented data on the management of cardiac arrest in children with pulmonary hypertension.^455–457 Most did not report patient-level data in children with pulmonary hypertension and cardiac arrest. These articles collectively highlight the increased risk of death in children with pulmonary hypertension and the results of recent international efforts in establishing a pediatric pulmonary hypertension classification to support future international and multisite research and general therapeutic management.

General approaches to improving cardiopulmonary physiology in the context of a pulmonary hypertension crisis or cardiac arrest are important. Children hospitalized with pulmonary hypertension are at higher risk of cardiac arrest than other children. The next steps should focus on generating original evidence in pulmonary hypertension disease groups characterized using contemporary classification systems and definitions. This disease remains relatively rare, which suggests that future research will require multicenter studies or large registry-based comparative studies to better understand the value of one intervention over another for treatment of cardiac arrest.

The PLS Task Force discussed the importance of using the classification of 5 groups and diagnoses detailed in the most recent international guidelines on pediatric pulmonary hypertension when studying the risk of cardiopulmonary arrest or interventions to treat cardiopulmonary arrest.^438,460,462

In children, including neonates, with pulmonary hypertension hospitalized for a clinical worsening event, we propose avoiding factors that may increase pulmonary vascular resistance while treating the aggravating condition to decrease the risk of cardiac arrest. Management strategies include avoiding hypoxia; hypercapnia; acidosis; stressors, such as pain, agitation, dehydration, or fluid overload; anemia; infection; or arrhythmias. Pulmonary hypertension–specific treatments (eg, inhaled nitric oxide, L-arginine, phosphodiesterase inhibitors [eg, milrinone, sildenafil], or endothelin-1 inhibitors [eg, bosentan]) may be considered (good practice statement).

In children who develop signs of pulmonary hypertensive crisis, low cardiac output, or right ventricular failure despite optimal medical therapy, ECMO may be considered before cardiac arrest or for refractory cardiac arrest (ie, ECPR) as a bridge to recovery or as a bridge to the evaluation for organ replacement and transplantation in very select cases (good practice statement).

Adaptation to air breathing immediately after birth requires that several critical interdependent physiologic events occur rapidly.⁴⁶⁸ Air breathing reduces pulmonary vascular resistance, which increases pulmonary blood flow. If the umbilical cord is clamped immediately, the increased pulmonary flow is initially from the aorta through the ductus arteriosus. If cord clamping occurs after the onset of breathing, the increased pulmonary blood flow can come from the placenta through the umbilical vein and ductus venosus, thereby maintaining left ventricular filling and output (vital for coronary and cerebral perfusion).⁴⁶⁹ Both milking the intact (not clamped or cut) umbilical cord and milking a long segment of clamped and cut cord have been proposed as alternatives to deferring clamping of the umbilical cord. Decisions about umbilical cord management can critically influence the cardiorespiratory adaptation after birth,^470,471 how and when other resuscitation interventions are provided, and mortality during subsequent hospitalization, particularly among preterm infants.⁴⁷²

The topic was last reviewed in by ILCOR in 2021.^473,474 Since then, additional RCTs have been completed and compiled into a very large pairwise individual patient data (IPD) meta-analysis and network meta-analysis (NMA), the iCOMP (Individual Participant Data on Cord Management at Preterm Birth) study,⁴⁷⁵ which provided higher-certainty evidence for various methods of umbilical cord management than could have been achieved with study-level meta-analysis alone.^472,476 The Neonatal Life Support Task Force used the process of adolopment to appraise this evidence and develop updated treatment recommendations.⁴⁷⁷ Task force members and content experts overlapped with the iCOMP study team, but assessment of suitability of the iCOMP analyses for adolopment was assessed by task force members and content experts who had no conflict of interest. The IPD meta-analysis is presented first and then the NMA, because the PICOST structure differs. The pairwise IPD meta-analysis was used for subgroup analyses, and the NMA was used for multiple between-intervention comparisons.

The iCOMP SysRev was registered before initiation (PROSPERO registration CRD42019136640). The full online CoSTR can be found on the ILCOR website.⁴⁷⁷

The NMA⁴⁷⁶ and the IPD meta-analysis identified 47 eligible studies including 6094 in‑fants.^{481–485,487–499,501,502,504–506,508,510,511,516,518–525,528,531–540} The median study sample size was 60 infants (IQR, 40–127). The median gestational age at birth was 29.6 weeks (IQR, 27.6–33.3). Of all infants, 61% were born by cesarean delivery, 17% were multiples, and 54% were male. The primary outcome was missing for 4 (<0.1%) infants.

Sufficient data were found to include comparisons of the following 5 interventions in the NMA:

For the outcomes of death before discharge, any intraventricular hemorrhage, and blood transfusion, the number of trials for each comparison ranged from 0 to 8 and the number of infants varied from 29 to 1993.⁴⁷⁶ The largest number of trials providing data for each outcome were for the cord milking compared with immediate cord clamping, for cord milking compared with medium deferral of cord clamping, and for immediate cord clamping compared with medium deferral of cord clamping. Note that in each case, the analysis was by intention to treat. Only 70% of the 47 trials reported treatment adherence.⁴⁷⁶ Key results are presented in Table 22.

For comparisons and outcomes not included in Table 22, clinical benefit or harm could not be determined, and details are provided in the online CoSTR.⁴⁷⁷

When ranking probabilities were calculated, to prevent death before discharge, long deferred cord clamping had a 91% probability of being the highest ranked treatment; immediate cord clamping had <1% probability of being the best treatment and a 53% probability of being the worst treatment; and medium-length deferred cord clamping and intact umbilical cord milking had a high probability of being second or third best.⁴⁷⁶

In infants born at <34 weeks’ gestational age who do not require immediate resuscitation after birth, we suggest deferring clamping the cord for at least 30 seconds (weak recommendation, moderate-certainty evidence).^473,474

In infants born at 28+0 to 33+6 weeks’ gestational age who do not require immediate resuscitation after birth, we suggest intact-cord milking as a reasonable alternative to deferring cord clamping (weak recommendation, moderate-certainty evidence).^473,474

We suggest against intact-cord milking for infants born at <28 weeks’ gestational age (weak recommendation, very low–certainty evidence).^473,474

In infants born at <34 weeks’ gestational age who require immediate resuscitation, there is insufficient evidence to make a recommendation with respect to cord management.^473,474

There is also insufficient evidence to make recommendations on cord management for maternal, fetal, or placental conditions that were considered exclusion criteria in many studies (in particular, multiple fetuses, congenital anomalies, placental abnormalities, alloimmunization, fetal anemia, fetal compromise, and maternal illness). In these situations, we suggest individualized decisions based on severity of the condition and assessment of maternal and neonatal risk (weak recommendation, very low–certainty evidence).^473,474

In preterm infants born at <37 weeks’ gestational age who are deemed not to require immediate resuscitation at birth, we recommend deferring clamping of the umbilical cord for at least 60 seconds (strong recommendation, moderate-certainty evidence).

In preterm infants born at 28+0 to 36+6 weeks’ gestational age who do not receive deferred cord clamping, we suggest umbilical cord milking as a reasonable alternative to immediate cord clamping to improve infant hematologic outcomes. Individual maternal and infant circumstances should be taken into account (conditional recommendation, low-certainty evidence).

We suggest against intact cord milking for infants born at <28 weeks’ gestation (weak recommendation, low-certainty evidence). There is insufficient evidence to make a recommendation concerning cut-cord milking in this gestational age group.

In preterm infants born at <37 weeks’ gestational age who are deemed to require immediate resuscitation at birth, there is insufficient evidence to make a recommendation with respect to cord management (weak recommendation, low-certainty evidence).

There is insufficient evidence to make recommendations on cord management for maternal, fetal, or placental conditions that were considered exclusion criteria in many studies (monochorionic multiple fetuses, congenital anomalies, placental abnormalities, alloimmunization or fetal anemia, fetal compromise, and maternal illness). In these situations, we suggest individualized decisions based on severity of the condition and assessment of maternal and neonatal risk (weak recommendation, very low–certainty evidence).

Whenever circumstances allow, the plan for umbilical cord management should be discussed between maternity and neonatal clinicians and parents before delivery and should take into account individual maternal and infant circumstances (good practice statement).

The complete evidence-to-decision table can be found in Appendix A. A table summarizing key points of the treatment recommendations is presented in Table S1 in Appendix C.

The strong recommendation for deferring cord clamping for at least 60 seconds in preterm infants <37 weeks’ gestation reflects the following considerations:

In making the suggestion to consider umbilical cord milking as an alternative to immediate cord clamping in infants born at 28+0 to 36+6 weeks’ gestation, the task force considered the following:

In making the suggestion against intact umbilical cord milking in infants <28 weeks’ gestation, but not in infants of higher gestational age, the task force considered the following:

There was insufficient evidence to make a recommendation concerning cord management of preterm infants who are deemed to require resuscitation at birth. This conclusion reflected the following:

The suggestion for individualized decision-making in the context of maternal, fetal, or placental conditions that were exclusion criteria is unchanged from 2021 and took into account that similar constraints applied to the results of the iCOMP systematic reviews.

In suggesting discussion before birth (whenever possible) about the plan for umbilical cord management, the task force considered that this approach is most likely to lead to the best decisions about what plan of cord management to use and how to coordinate the steps in care of the infant among different care professionals and the parents.

Both term and preterm newborn infants are at high risk of hypothermia during and immediately after resuscitation in high-, middle-, and low-income countries.^547–549 Previous large observational studies have found an association between hypothermia and neonatal mortality and morbidity.^550–557 The optimal rate of rewarming for unintentionally hypothermic infants has not been defined. Slow rewarming could prolong metabolic demands and increase adverse outcomes of hypothermia such as apnea, respiratory distress, and hypoglycemia,^550,558,559 but there is a suggestion from a few preclinical and clinical studies in other age groups and contexts (such as after therapeutic hypothermia) that rapid rewarming could be harmful.⁵⁶⁰ In 2020, the Neonatal Life Support Task Force undertook an evidence update which concluded that there were sufficient new studies to consider updating the systematic review.⁵⁶¹ The SysRev was registered before initiation (PROSPERO registration CRD42022359005). The full online CoSTR can be found on the ILCOR website.⁵⁶²

The review identified 1 RCT of 42 infants comparing maximum temperature set points for the servo-controlled radiant warmers used for rewarming; rates of rewarming depended on these set points.⁵⁶³ The study enrolled only otherwise well, term newborn infants of normal birth weight. The review also identified 2 observational studies including a total of 280 infants, one of which included only infants born at ≤28 weeks’ gestation or birth weight ≤1000 g⁵⁶⁴ while the other enrolled only infants with birthweight <1500 grams.⁵⁶⁵ For the critical outcome of mortality, these 2 studies could not exclude benefit or harm from rapid rewarming compared with slow rewarming (RR, 1.09 [95% CI, 0.7–1.71]; absolute risk difference, 17 fewer deaths per 1000 infants [95% CI, from 58 fewer–138 more]; low-certainty evidence).^564,565

For other critical and important outcomes, either data were inconclusive or there were no data.

The confidence in effect estimates is so low that a recommendation for either rapid rewarming (0.5 °C/h or greater) or slow rewarming (0.5°C/h or less) of unintentionally hypothermic newborn infants (temperature <36 °C) at hospital admission would be speculative.⁵⁶⁶

In newborn infants who are unintentionally hypothermic after birth, rewarming should be started, but there is insufficient evidence to recommend either rapid (≥0.5˚C/h) or slow (<0.5˚C/h) rates of rewarming.

Regardless of the rewarming rate chosen, a protocol for rewarming should be used. Frequent or continuous monitoring of temperature should be undertaken, particularly if using a supraphysiological set temperature point to accelerate the rewarming rate, because of the risk of causing hyperthermia. In any hypothermic infant, monitor blood glucose because there is a risk of hypoglycemia (good practice statement).

The complete evidence-to-decision table can be found in Appendix A.

Therapeutic hypothermia is now standard care in high-income countries for the treatment of moderate or severe hypoxic ischemic encephalopathy in term and near-term infants.⁵⁷⁰ However, uncertainty persists about the efficacy of therapeutic hypothermia in low-resource settings or in low- and middle-income countries. Because asphyxia is a leading cause of neonatal mortality and morbidity in low- and middle-income countries, it is critical to determine whether therapeutic hypothermia improves mortality and neurodevelopmental outcomes in this setting. The treatment shown to be effective in high-income countries generally consists of cooling to 33.5 °C commencing within 6 hours of birth and for a duration of 72 hours. Servo-controlled cooling devices are increasingly used in high-income countries because they achieve more consistent adherence to target temperatures,⁵⁷¹ although effective cooling can be accomplished by removal of heat sources and clothing and by applying refrigerated gel packs, making the treatment feasible in low-resource settings.⁵⁷² The topic was last reviewed by the task force in 2015, with an emphasis on the use of passive hypothermia or cold packs.⁴⁶⁸ An evidence update in 2020⁵⁶¹ identified new studies and an ongoing large multicenter RCT that has since been published.⁵⁷³

The SysRev was registered before initiation (PROSPERO registration CRD42022360554). The full online CoSTR can be found on the ILCOR website.⁵⁷⁴

Neurodevelopmental impairment was defined as abnormal motor, sensory, or cognitive function using an appropriate standardized test.

The systematic review identified 21 RCTs involving 2145 infants with hypoxic ischemic encephalopathy.^575–595 Most studies were single site, but 3 were multicenter.^585,592,594 Key results are summarized in Table 23.

Apart from persistent pulmonary hypertension, reporting of adverse events during therapeutic hypothermia was inconsistent between studies. Subgroup analysis suggested that non–servo-controlled methods were more efficacious, although the task force considered that these results were more likely due to other aspects of study design than to a benefit of non–servo-controlled methods.

We suggest that newborn infants at term or near term with evolving moderate-to-severe hypoxic-ischemic encephalopathy in low-income countries and/or other settings with limited resources may be treated with therapeutic hypothermia (weak recommendation, low-quality evidence).⁵⁶⁶

Cooling should only be considered, initiated, and conducted under clearly defined protocols with treatment in neonatal care facilities with the capabilities for multidisciplinary care and availability of adequate resources to offer intravenous therapy, respiratory support, pulse oximetry, antibiotics, antiseizure medications, and pathology testing. Treatment should be consistent with the protocols used in the randomized clinical trials in developed countries, that is, cooling to start within 6 hours, strict temperature control at 33 °C to 34 °C for 72 hours, and rewarming over at least 4 hours.⁵⁶⁶

We suggest the use of therapeutic hypothermia in comparison with standard care alone for term (≥37+0 weeks’ gestational age) newborn infants with evolving moderate-to-severe hypoxic-ischemic encephalopathy in low- and middle-income countries in settings where a suitable level of supportive neonatal care is available (weak recommendation, low-certainty evidence).

For late preterm infants, 34+0 to 36+6 weeks’ gestational age infants, a recommendation cannot be made due to insufficient evidence.

Therapeutic hypothermia should only be considered, initiated, and conducted under clearly defined protocols with treatment in neonatal care facilities with the capabilities for multidisciplinary care and availability of adequate resources to offer intravenous therapy, respiratory support, pulse oximetry, antibiotics, antiseizure medication, transfusion services, radiology (including ultrasound), and pathology testing, as required. Treatment should be consistent with the protocols used in RCTs. Most protocols included the starting of cooling within 6 hours after birth, strict temperature control to a specified range (typically 33 °C–34 °C) and most commonly for a duration of 72 hours with rewarming over at least 4 hours. Adoption of hypothermia techniques without close monitoring, without protocols, or without availability of comprehensive neonatal intensive care may lead to harm (good practice statement).

The complete evidence-to-decision table can be found in Appendix A.

Specialized post–cardiac arrest care at a cardiac arrest center (CAC) may improve long-term survival from OHCA. Previous studies have reported an association between survival to hospital discharge and transport to a CAC, but there is inconsistency in the hospital factors that are most related to patient outcome.⁵⁹⁸

In 2020, ILCOR reviewed the evidence on CACs despite a lack of high-quality data to support their implementation.²³² Since then, new evidence on CACs has been published, triggering this update of the SysRev SysRev (PROSPERO number CRD42018093369). CACs are defined as specialized institutions offering treatment or services for patients with OHCA, including a coronary angiography laboratory with 24/7 percutaneous coronary intervention, post–cardiac arrest temperature control, extracorporeal membrane oxygenation, mechanical ventilation, and neurologic prognostication.⁵⁹⁹ For this review, we defined CAC as having the capability for 2 or more of the above interventions and explicitly referred to by study authors as CACs (or synonymous terms such as critical care medical center, tertiary heart center, or regional center).⁶⁰⁰ We excluded studies that used high volume (number of cases/patients) or percutaneous coronary intervention capability as the only distinguishing characteristics. The full CoSTR can be found online.⁶⁰¹

Sixteen studies were included in our review.^602–617 All studies had moderate to serious risk of bias from confounding, and the certainty of evidence was rated as low. Because of substantial heterogeneity, no meta-analyses could be performed.

Individual study details are provided in the published SysRev and online.⁶⁰¹ Two studies showed improved outcomes associated with treatment at a CAC for survival to 30 days with favorable neurological outcomes (Figure 1),^603,604,617a 11 for hospital discharge with favorable neurological outcomes (Figure 2),^{602,605–612,615,616} and 2 for survival to 30 days (Figure 3).^602,608

The only RCT identified did not show any difference in outcomes, but its results were limited to non–ST-segment–elevation myocardial infarction patients with prehospital ROSC in an urban setting. Findings were not generalizable to other patient cohorts.⁶⁰² Thirteen observational studies showed improved outcome of survival to hospital discharge associated with care at a CAC (Figure 4).^{603,605–614,616,617} Three observational studies showed improved outcome for ROSC associated with care at a CAC (Figure 5).^604,606,613

We suggest adult patients with nontraumatic OHCA be cared for in CACs rather than in non-CACs (weak recommendation, very low–certainty evidence).^609a

We suggest adults with OHCA should be cared for in cardiac arrest centers (weak recommendation, low-certainty evidence).

The complete evidence-to-decision table is provided in Appendix A.

The management of cardiac arrest and other medical emergencies can be complex. Cognitive aids have been widely adopted to enhance adherence to guidelines, improve performance, and reduce errors. These aids may provide a structured framework and clinical guidance through complex and dynamic processes. Resuscitation councils worldwide use cognitive aids during training and clinical practice in the form of algorithms, flow charts, checklists, posters, digital applications, and other formats. Whether use of such cognitive aids during resuscitation improves performance and patient outcomes is uncertain.

ILCOR reviewed the evidence in 2020 and did not recommend cognitive aids for laypeople during training and real CPR; however, they were suggested for training of health care professionals.^620,621 Since then, new evidence has been published, triggering this update of the SysRev (PROSPERO registration CRD42020159162).⁶²² The complete CoSTR can be found online.⁶²³

All 29 studies included in this review were simulation studies that investigated the use of cognitive aids to facilitate clinical performance. No study investigated cognitive aids as an educational tool to improve knowledge acquisition. No meta-analyses could be performed because of a high degree of heterogeneity in the studies, and the overall certainty of evidence was very low for all outcomes. Details of individual studies are included in the published review and online.⁶²³

Four simulation studies^624–627 investigated the effects of cognitive aids in neonatal resuscitation by health care professionals. Findings included improvement in performance score with a decision support tool using augmented reality (AR),⁶²⁷ fewer deviations from a resuscitation algorithm with a decision support tool with auditory and visual prompts,⁶²⁵ and improved adherence to a resuscitation algorithm and improved performance according to a guideline with audio voice guidance.⁶²⁶ A poster of an algorithm demonstrated no difference in performance.⁶²⁴

The use of cognitive aids during simulated pediatric resuscitation was assessed in 3 studies^628–630 and showed no difference in CPR performance by using a noninteractive CPR checklist,⁶³⁰ and no difference in CPR quality metrics with a decision support app.⁶²⁹ However, improved adherence to protocols or processes was found in 2 RCTs.^628,629 A computer-based resuscitation tool improved task completion,⁶²⁸ and a decision support app found significantly fewer deviations from guideline recommendations.⁶²⁹

Eight studies^631–638 used interactive cognitive aids during adult ALS simulated resuscitation (smartphone apps,^631,635,637 tablet apps,^633,634,636 computer-based clinical decision display system^632,638) with improved adherence to a protocol or process in all studies.

Five studies^639–643 investigated the effects of cognitive aids (noninteractive checklists) used by health care professionals managing other emergencies in simulated events. In 4 RCTs: average performance scores increased,⁶⁴¹ failure to adhere to critical steps was reduced,⁶³⁹ use of a medical emergency checklist improved adherence to critical process steps,⁶⁴² and longer checklists seemed to be superior to shorter checklists or no checklist for overall CPR performance on procedural variables but not for CPR quality.⁶⁴³ Access to crisis checklists shortened time to adequate administration of glucose in a hypoglycemic coma scenario.⁶⁴⁰

Seven RCTs^644–650 and 2 observational studies^651,652 investigated the effects of cognitive aids used by lay rescuers during simulated resuscitation. Three RCTs^645,646,648 of mobile phone applications found improved adherence to clinical processes, while another mobile phone application RCT⁶⁵⁰ found no improvement. Other RCTs found that using instruction cards improved adherence to AED sequences and time to shock,⁶⁴⁴ a voice-activated visual and auditory-assisted decision device improved adherence to a 30:2 CPR ratio,⁶⁴⁷ and use of a flowchart demonstrated reduced hands-off time during CPR.⁶⁴⁹

An observational study⁶⁵¹ investigated the use of speech recognition software and found improved adherence to a clinical protocol assessed in an objective structured clinical examination. Another observational study⁶⁵² investigated the feasibility of Chatbot guidance, which produced mixed results.

Three studies reported undesirable effects: increase in time to commencing chest compressions^647,649 and delays in calling emergency services.⁶⁴⁸

The complete evidence-to-decision tables are provided in Appendix A.

Current methods for training laypeople and health care professionals often fall short, resulting in poor skill acquisition and long-term skill decay. Identification of alternative educational strategies with improved learning outcomes will help to enhance process of care and patient outcomes from cardiac arrest. Immersive technologies, such as virtual reality (VR; defined as real-time simulation and interactions through sensorial channels created by a computer and displayed on a head-mounted or smartphone device)⁶⁵³ and AR (defined as computer-generated holographic images overlaid into the real environment enabling users to interact with both the hologram and real objects),⁶⁵⁴ provide an alternative learning modality to traditional instructor-led training. These technologies can support training when combined with other instructional methodologies such as video, manikin-based training, or online learning. Implementation of immersive technology comes with a cost for both hardware and software components. VR and AR technology have been used in educational settings for both laypeople and health care professionals, but ILCOR has not previously reviewed the available evidence. A SysRev was initiated because the overall impact of VR and AR on learning and performance outcomes is unclear (PROSPERO registration CRD42023376751).⁶⁵⁵ The full CoSTR can be found online.⁶⁵⁶

No meta-analyses could be performed because of a high degree of heterogeneity in the studies, and the overall certainty of evidence was very low for all outcomes. Details of individual studies are included in tables in the published review and online.⁶⁵⁶

Out of 18 studies^{653,654,657–672} included in this review, 3 studies used AR in BLS training.^653,654,658 Two of these used AR to provide real-time CPR feedback, with 1 study favoring AR and the other favoring the non-AR feedback.^653,658 The third study used AR to provide clinical guidance during training, and results favored the AR intervention but were not significant.⁶⁵⁴

Of the 3 studies investigating AR, 2 demonstrated no difference in CPR depth performance with and without use of AR during training.^653,654 One study reported better CPR depth compliance with the use of AR during training.⁶⁵⁸ Two studies showed no difference in CPR-quality parameters (compression depth and rate),^653,654 while an additional study found no difference in compression rate but a difference in depth with the use of AR during training.⁶⁵⁸ Overall CPR performance was assessed in 2 studies^653,658 and demonstrated mixed results.

VR for BLS was explored in 9 studies assessing laypeople ^{657,659–665,672} and 3 studies of health care professionals.^666–668 All featured VR as the primary instructional methodology. An additional 3 studies described VR use for ALS training in health care professionals.^669–671 Because of significant heterogeneity in the design of the interventions, control groups, participant types, and outcome measures, meta-analysis was not possible.

Six studies looked at VR for acquisition of BLS knowledge. Knowledge acquisition was significantly greater with VR in 3 studies compared with a serious game,⁶⁶⁶ e-learning with video,⁶⁶¹ and video-based training.⁶⁶² Two studies showed no difference compared with traditional training⁶⁶⁴ or video-based training.⁶⁶³ Knowledge retention with kindergarten teachers improved at 5 weeks after training with VR.⁶⁶² Two other studies showed no difference at 6 months.^660,664

Nine studies investigated the effects of VR on BLS skills outcomes. Adult laypeople achieved significantly greater chest compression fraction with instructor-led training compared with VR.⁶⁵⁷ Results for no-flow time were mixed. One study favored VR over web-based BLS training,⁶⁶⁸ and the other favored conventional BLS training over VR.⁶⁶⁷

Three studies in adult laypeople showed significantly better CPR depth in the control group compared with VR.^657,659,672 Two other studies showed no difference in CPR depth between groups.^664,665 Participants in instructor-led CPR training had significantly better CPR depth compliance compared with VR.^657,672 One study demonstrated higher CPR rates with VR.⁶⁵⁷ Two other studies found no difference in CPR rate.^659,665 CPR rate compliance was not better with VR; CPR rate compliance was either better for instructor-led training,^657,672 or no difference was found.⁶⁶⁴ One study reported better chest recoil compliance with VR,⁶⁵⁷ but 3 studies demonstrated no difference.^664,665,672 For overall CPR performance after training, 3 studies found no difference when comparing VR with instructor-led training^665,672 or video-based training.⁶⁶³ Two studies measured retention of CPR skills at 6 months⁶⁶⁴ and 3 months⁶⁷² after training and found no difference in CPR depth, rate, or chest recoil when comparing traditional training and VR.^664,672

A study in adult laypeople found more willingness to perform CPR with instructor-led CPR training at 6 months after training than with VR-based CPR training (81% willing in the instructor-led control group compared with 71% in the VR intervention group, P=0.02).⁶⁶⁰

Three studies investigated VR for ALS training. A study in neonatal resuscitation compared high-fidelity simulation with VR and showed no difference in knowledge immediately after training.⁶⁷¹ An advanced cardiovascular life support study found significantly improved adherence to guidelines with traditional training compared with VR training with limited feedback. No difference was found when comparing traditional training with VR training with comprehensive feedback.⁶⁶⁹ An additional study found no difference in objective structured clinical examination scores for clinical performance between standard Helping Babies Breathe training and VR-based Helping Babies Breathe immediately after training and 6 months later.⁶⁷⁰

We suggest the use of either AR or traditional methods for BLS training of laypeople and health care professionals (weak recommendation, very low–certainty evidence).

We suggest against the use of virtual reality only for BLS and ALS training of laypeople and health care professionals (weak recommendation, very low–certainty evidence).

The complete evidence-to-decision table can be found in Appendix A.

Increased familiarity and ease with technology and digital media are features of younger generations. More effective teaching strategies for these learners may include a greater degree of stimulation and engagement with the use of active participation with and alongside peers. Gamification refers to the use of game-like elements (competition, point systems, scaffolded levels of difficulty, leaderboards), usually in a digital format, to encourage interactive and intuitive participation by learners. Some preliminary studies have found that gamified learning improves knowledge and skill during CPR training, either alone or used as pretraining to a standard life support course; other studies have found no significant difference. The task force undertook a SysRev because the impact of gamified learning on learning and performance outcomes is unclear (PROSPERO registration CRD42023483540).⁶⁷³ The full CoSTR can be found online.⁶⁷⁴

Six randomized trials and 7 observational studies were identified.^675–687 Details of study design and key findings are presented in table form in the published review and online.⁶⁷⁴ No meta-analyses could be performed because of a high degree of heterogeneity in the studies, and the overall certainty of evidence was low to very low for all outcomes.

Eleven studies used digital platforms, including online or screen-based platforms,^{675,676,681,684,685,687} a digital leaderboard,^677,680,681 and smartphone applications.^683,686 One study used a board game, and another a card game.^678,679 Eleven studies involved health care professionals,^{675–683,686,687} and 2 involved laypeople (high school students).^684,685 Three studies examined performance of teams^679,685,686; the remaining 10 examined individual performance. No study reported on outcomes of process, costs, and resources utilization, or on critical clinical and patient outcomes.

Overall CPR performance was addressed in 4 RCTs^{676,677,681,682} and 1 observational study.⁶⁸⁵ Three RCTs^676,681,682 found better performance with gaming for health care professionals and laypeople. A multicenter RCT found no effect.⁶⁷⁷ The observational study in laypeople found improved performance 6 months after training with gaming.⁶⁸⁵ In an observational study of BLS training amongst high school students using a screen-based gamified learning interface, chest compression depth and rate was improved immediately after training and remained improved 3 months later.⁶⁸⁴

Two observational studies of health care professionals demonstrated improved knowledge scores after gamified learning during the Neonatal Resuscitation Program, a finding that persisted at 6 months in 1 of the studies.^678,687 A card game to enhance Neonatal Resuscitation Program knowledge reported high levels of perceived usefulness.⁶⁷⁹ Another observational study found improved skills scores and faster time to positive pressure ventilation in a neonatal scenario that followed gamified learning.⁶⁷⁵

For ALS knowledge, 2 RCTs in health care professionals showed improvements with smartphone-based games.^683,686 The latter study showed no difference for skills during ALS scenarios used in a smartphone-based game involving ALS scenarios but led to better self-reported confidence among users.

An observational study⁶⁸⁰ of nurses using a leaderboard showed decreased time to epinephrine dosing in children as well as increased proportion of learners knowing the correct concentration of epinephrine.

We suggest the use of gamified learning be considered as a component of resuscitation training for all types of BLS and ALS courses (weak recommendation, very low–certainty evidence).

The complete evidence-to-decision table is provided in Appendix A.

Rapid cycle deliberate practice (RCDP) is a type of training in which feedback occurs immediately and frequently during the training. It should not be confused with repetitive practice. RCDP is characterized by a goal to be achieved, a stop-and-go practice with immediate feedback on the performance, ample time for repetition to improve performance aiming to improve clinical outcomes, and a safe environment that fosters an atmosphere where learners have no fear of making mistakes and receive feedback from a constructive perspective.⁶⁸⁸ ILCOR has not previously reviewed available evidence about RCDP in resuscitation training. Therefore, a SysRev was initiated (PROSPERO registration CRD42023468862).⁶⁸⁹ The full CoSTR can be found online.⁶⁹⁰

Seven RCTs^691–697 and 1 observational before-after study⁶⁸⁸ were identified, all in simulation settings.^{688,691–697} The studies included medical students,⁶⁹⁶ interns,^693,694 residents,^688,692,697 physicians,⁶⁹⁵ and a mix of fellows, nurses, and respiratory therapists⁶⁹¹: all involved in adult,^695,696 pediatric,^{688,691,692,694,697} and neonatal⁶⁹³ simulated scenarios. Seven of them referred directly to RCDP^{688,691–695,697}; 1 used “in-simulation debriefing” during the clinical scenario, which contained the key components of RCDP.⁶⁹⁶

Details of the individual simulation studies are presented in the published review and online.⁶⁹⁰ Meta-analysis was only possible for time to chest compressions.

For time to chest compressions, 2 pediatric^692,697 studies and 1 neonatal⁶⁹³ study provided very low–certainty evidence of no benefit from RCDP when compared with after-event debriefing (Figure 6). In an observational study, RCDP resulted in a significantly shorter time from cardiac arrest to initiation of chest compressions.⁶⁸⁸

A single RCT found no benefit in time to recognition of cardiac arrest with RCDP.⁶⁹⁵ An observational study found no benefit in time to bag-mask ventilation.⁶⁸⁸ In an RCT, time to positive-pressure ventilation within 1 minute was more frequent with RCDP than in the control.⁶⁹³ Three RCTs^692,695,697 and 1 observational study⁶⁸⁸ assessed time to defibrillation, with shorter time from rhythm recognition to defibrillation in 2 RCTs^692,695 and in the observational study.⁶⁸⁸ Two RCTs assessed time to administration of epinephrine,^692,693 with 1 study describing a benefit with RCDP.⁶⁹³ RCDP also resulted in shorter pre-defibrillation pause durations in 2 studies.^688,695 RCDP improved compression fraction/no-flow fraction in an RCT⁶⁹⁵ and in an observational study.⁶⁸⁸ Retention of skills at 4 months was analyzed in an RCT, and there was no difference with RCDP.⁶⁹³

For adherence to protocol, 1 RCT reported higher scores,⁶⁹³ but 2 others found no difference.^691,694 Team leader performance was better with RCDP in 1 study.⁶⁹⁷ In contrast, participants’ subjective perception of the teaching effectiveness scored lower for RCDP.⁶⁹⁶

We suggest that it may be reasonable to include RCDP as an instructional design feature of BLS and ALS training (weak recommendation, very low–certainty evidence).

The complete evidence-to-decision table is provided in Appendix A.

Team competencies are defined as nontechnical skills, including team-related communication, task allocation, and leadership, that are known to be associated with patient outcomes in resuscitation. Investigating whether specific training of team competencies improves resuscitation performance could impact the organization of resuscitation services worldwide and potentially improve patient care. In 2020 we recommended the use of specific leadership training for resuscitation courses on the basis of very low–certainty evidence.⁶²⁰ This SysRev aimed to assess the effect of specific training on a broader range of team competencies as part of resuscitation training (PROSPERO registration CRD42023473154).⁶⁹⁸ The full CoSTR can be found online.⁶⁹⁹

Seventeen studies were included in this review, and individual study details are provided in the published review and online.^699–716 No evidence was identified for CPR-skill quality and performance, confidence, and team competencies beyond 1 year. One RCT⁷⁰⁵ reported descriptive data on patient survival outcomes favoring team competencies, but this was not powered to make inferences.

For CPR skills and quality at course completion, 2 RCTs^700,710 reported shorter time to at least 1 CPR-skills performance. One nonrandomized study for pediatric ALS⁷⁰⁶ reported higher checklist scores for CPR skills with team training, and 1 RCT⁷⁰⁴ found greater adherence to ALS guidelines. Nine studies (1 observational,⁷⁰⁶ 8 RCTs^{702,705,709–711,713,715,716}) reporting CPR performance found no effect from team competence training. One RCT⁷⁰¹ reported shorter no-flow time, whereas another found no difference.⁷⁰⁴ Two studies found no difference in hands-on time or compression rate⁷⁰⁹ or chest compression quality.⁷⁰⁸

Two RCTs found no difference in CPR performance at 4 months⁷¹⁶ and 6 months.⁷¹¹ Another RCT⁷⁰⁹ reported increased hands-on time and higher compression rates 4 months after course completion. Confidence at course completion and at a nonspecified follow-up interval showed was not different in 1 RCT.⁷⁰²

Team competencies were evaluated at course completion by 14 studies (12 RCTs,^{700–703,707–710,713–716} 2 nonrandomized studies^706,712). Three RCTs^708,709,714 reported more leadership statements, 3 RCTs^703,713,714 identified increased directed team communication, 1 RCT⁷¹³ found increased closed-loop communication, and another RCT⁷⁰¹ reported higher “teamwork verbalizations” (eg, directed orders, task assignments, planning).

Decision-making improved in 1 RCT.⁷⁰⁸ Leadership behavior was better in 2 RCTs,^705,707 with 1 also reporting increased correction of improper chest compressions. A nonrandomized study⁷¹² reported no difference in leadership behavior.

Teamwork improved in 1 RCT⁷⁰² with higher team-level efficacy, and 1 nonrandomized study⁷⁰⁶ reported more teamwork intervention events. Two RCTs^715,716 and a nonrandomized study⁷¹² found no differences in teamwork measures. Nontechnical skills performance was found to be higher in 2 RCTs,^700,710 and 2 RCTs^714,715 reported improved workload management.

Beyond course completion, 1 RCT reported more leadership statements, task assignments, commands, and decisions at 4 months.⁷⁰⁹ Another RCT found higher ratings on a self-reported teamwork scale,⁷⁰² but no difference was found in teamwork scores at 3 months in another RCT.⁷¹⁶

We suggest that specific team and leadership training be included as part of ALS training for health care providers (weak recommendation, very low–certainty evidence).⁶²⁰

We suggest that teaching team competencies be included in BLS and ALS training (weak recommendation, very low–certainty evidence).

The complete evidence-to-decision table is provided in Appendix A.

The task force undertook this ScopRev because the individual backgrounds of specific populations (eg, working in a special environment, someone with special needs, impairments, or disabilities) who are not health care professionals may warrant specific BLS training that differs from standard courses.^717–719 However, it is unclear which specific populations exactly could benefit from adapted tailored teaching. The complete report of this ScopRev can be found online.⁷²⁰