Conflict of Interest Declaration
The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. The following Task Force members and other authors were recused from the discussion as they declared a conflict of interest: none applicable
The following Task Force members and other authors declared an intellectual conflict of interest and this was acknowledged and managed by the Task Force Chairs and Conflict of Interest committees: none applicable
Dunne C, Morgan P, Bierens J, Olasveengen T, Morley PT, Perkins GD. on behalf of the International Liaison Committee on Resuscitation BLS Life Support Task Force(s).
Ventilation of compression first strategies for drowning Consensus on Science with Treatment Recommendations [Internet] Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) Advanced Life Support Task Force, 2021 Dec 6. Available from: http://ilcor.org
There is ongoing debate in the scientific literature regarding the merits of commencing resuscitation with chest compressions prior to ventilations. Existing ILCOR recommendations for adult BLS “suggests commencing CPR with compressions rather than ventilations (weak recommendation, very-low-certainty evidence)” whilst the paediatric task force concluded that there was insufficient evidence to make a recommendation. The evidence base informing this recommendation is limited to data from four manikin studies with no human studies previously identified. Unlike the majority of adult cardiac arrests and some paediatric cardiac arrests which arise primarily due to a cardiac cause, drowning leading to cardiac arrest is primarily caused by hypoxia. Whether a different approach in the special circumstances associated with drowning warrants an alternative approach is uncertain.
This review was initiated following a request from the American Heart Association. The review was led by a group of drowning experts commissioned to undertake a series of reviews relating to drowning.
The continuous evidence evaluation process for the production of Consensus on Science with Treatment Recommendations (CoSTR) started with a systematic review the literature (Perkins et al 2021 PROSPERO CRD42021259983) conducted by Patrick Morgan, Cody Dunne, Samantha Johnson, Joost Bierens and Gavin Perkins with involvement of clinical content experts.
Evidence for adult and paediatric literature was sought and considered by the Basic Life Support Adult Task Force and the Paediatric Task Force groups respectively. These data were taken into account when formulating the Treatment Recommendations.
Adults and children in cardiac arrest1 following drowning2
Resuscitation which follows a compression first strategy (CAB)
Resuscitation which starts with ventilation first (ABC)
Critical 9: Survival to discharge / 30 days or later
Critical 8: Survival with favourable neurological outcome to discharge / 30 days or later
Critical 7: Return of spontaneous circulation (ROSC)
Randomized controlled trials (RCTs) and non-randomized studies (non-randomized controlled trials, interrupted time series, controlled before-and-after studies, cohort studies) are eligible for inclusion.
Unpublished studies (e.g., conference abstracts, trial protocols), manikin studies, narrative reviews and animal studies were excluded.
All years and all languages are included as long as there is an English abstract
Database inception to current time.
1A broad definition of cardiac arrest will be used including those who are unconscious and not breathing normally or those requiring resuscitation interventions e.g. chest compressions, defibrillation.
2 Drowning is the process of experiencing respiratory impairment from submersion/immersion in liquid
PROSPERO Registration CRD42021259983
Consensus on Science
A search of Medline, Pre-Medline, Embase, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials identified 1085 references. After de-duplication of references 730 references were reviewed. After review of titles and abstracts 9 papers were shortlisted for full text review. No studies were identified which addressed the PICOST question.
- We recommend a compression-first strategy (CAB) for lay persons providing resuscitation for adults and children in cardiac arrest due to drowning (Good practice statement)
This prioritizes simplicity and cohesiveness in training recommendations for lay persons, with the goal of faster resuscitation initiation. This is supported by manikin studies finding limited delay in ventilations even with a compression-first strategy.
- We recommend that health care professionals and those with a duty to respond to drowning (e.g. lifeguards) consider providing rescue breaths / ventilations first (ABC) prior to chest compressions if they have been trained to do so. (Good practice statement)
This considers that indirect evidence suggests earlier ventilations may improve prognosis, and the specialized training of lifeguards and healthcare professionals (including cardiac monitoring and ventilation-delivery equipment). The current evidence is unclear if earlier ventilations improve outcomes once cardiac arrest has occurred, or if the benefit is in preventing respiratory arrest deteriorating into cardiac arrest.
Justification and Evidence to Decision Framework
Seven hundred and thirty abstracts were reviewed, of which 9 proceeded for a full text read. Ultimately, no studies were identified as relevant to the PICO question comparing initial resuscitation strategies (ventilation-first or compression-first) for cardiac arrests due to drowning. In order to determine good practice statements, the reviewers identified literature and other consensus statements which indirectly related to the research question.
Rationale for the ventilation-first strategy (differing from adult BLS treatment recommendations) is due to the hypoxic mechanism of cardiac arrest in drowning, and belief that earlier ventilations will reverse the hypoxia sooner, and either prevent the patient from progressing from respiratory arrest to cardiac arrest or increase the likelihood of Return of Spontaneous Circulation (ROSC) after correcting the underlying aetiology.
This similar rationale is commonly held in paediatric cardiac arrest, where hypoxia is a more common than aetiology than primary cardiac events.[Lee 2019 7032] ILCOR reviewed the evidence for initial resuscitation strategy in paediatric cardiac arrest in both 2015 and 2020.[De Caen 2015 S177; Maconochie 2020 S140] No human studies were identified, and the task force did not recommend either strategy as superior. Instead, noting that a compression-first strategy prioritized uniformity with adult guidelines and simplicity, and a ventilation-first strategy prioritized hypoxia reversal sooner. Two manikin RCT studies were identified in the review that demonstrated ventilations were only delayed by 5.7-6.0s with a compression-first strategy compared to ventilation-first.[Marsch 2013 w13856; Sekiguchi 2013 1248]
There is only indirect evidence to support a ventilation-first strategy. Another systematic review is presently determining the impact of any ventilations at all as part of the resuscitation strategy, however a recent scoping review identified bystander CPR including ventilations as favourable for survival.[Bierens 2021 205]
In addition, one retrospective observational study compared in-water resuscitation (i.e., ventilations) versus none for drowning victims in respiratory (and possibly cardiac) arrest. Survival (87.5% versus 25.0%) and survival with favourable neurological outcome (52.6% versus 7.4%) was higher in the in-water resuscitation cohort.[Szpilman 2004 25] Another study describes significantly worse neurological outcomes in paediatric drowning patients who experience cardiac arrest compared to respiratory arrest only (81% versus 0%, p<0.001). By intervening with ventilations early in the arrest process before the heart has stopped (i.e., addressing the hypoxic mechanism), one may prevent worse outcomes.[Mtaweh 2015 91]
Of note, no direct or indirect evidence is available to support any certain number of initial ventilations if lifeguards or healthcare professionals adopt a ventilation-first strategy. Most importantly, resuscitation should not be delayed by either selected strategy.
There were no studies which directly evaluated this question. Further research, informed by the Utstein template for drowning may usefully address this on-going uncertainty.
Attachment: There is no ETD table as no evidence was identified.
References listed alphabetically by first author last name in this citation format (Circulation)
- Lee J, Yang WC, Lee E, Huang J, Hsiao H, Lin M, et al. Clinical survey and predictors of pediatric out-of-hospital cardiac arrest admitted to the Emergency Department. Nature. 2019;
- De Caen AR, Maconochie IK, Aickin R, Atkins DL, Biarent D, Guerguerian AM. Part 6: Pediatric Basic Life Support and Pediatric Advanced Life Support. Circulation. 2015; 132(16):S177-S203. https://doi.org/10.1161/CIR.0000000000000275
- Maconochie IK, Aickin R, Hazinski MF, Atkins DL, Bingham R, Couto TB, et al. Pediatric Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Circulation. 2020;142:S140-S184. https://doi.org/10.1161/CIR.0000000000000894
- Marsch S, Tschan F, Semmer NK, Zobrist R, Hunziker PR, Hunziker S. ABC versus CAB for cardiopulmonary resuscitation: a prospective, randomized simulator-based trial. Swiss Med Wkly. 2013; 143:w13856. https://doi.org/10.4414/smw.2013.13856.
- Sekiguchi H, Kondo Y, Kukita I. Verification of changes in the time taken to initiate chest compressions according to modified basic life support guidelines. Am J Emerg Med. 2013; 31:1248–1250. https://doi.org/10.1016/j.ajem.2013.02.047
- Bierens J, Abelairas-Gomez C, Barcala-Furelos R, Beerman S, Claesson A, Dunne C, et al. Resuscitation and emergency care in drowning: A scoping review. Resuscitation. 2021;162:205-217. https://doi.org/j.resuscitation.2021.01.033
- Szpilman D, Soares M. In-water resuscitation – is it worthwhile? Resuscitation. 2004;63:25-31.
- Mtaweh H, Kochanek PM, Carcillo JA, Bell MJ, Fink EL. Patterns of multiorgan dysfunction after pediatric drowning. Resuscitation. 2015;90:91-96. https://doi.org/10.1016/j.resuscitation.2015.02.005