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
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: Theresa Olasveengen
CoSTR Citation
Cash R, Nehme Z, de Caen A, Perkins G, Dewan M, Dicker B, Dassanayake V, Raffay V, Vaillancourt C, Olasveengen T, Tjelmeland I, Kleinman M, Bray J, on behalf of the International Liaison Committee on Resuscitation (ILCOR) Basic Life Support Task Force. Dispatcher-assisted Compression-only CPR compared with Conventional CPR in Adults Consensus on Science with Treatment Recommendations [Internet] Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) Advanced Life Support Task Force, 2nd November 2024. Available from: http://ilcor.org
Methodological Preamble and Link to Published Systematic Review
The continuous evidence evaluation process for the production of Consensus on Science with Treatment Recommendations (CoSTR) started with a systematic review of basic life support (Ashoor 2017 112 – PROSPERO CRD42016047811) conducted by the Knowledge Synthesis Unit at St Michael’s Hospital, Toronto, Canada with involvement of clinical content experts. Following a review of the Ashoor et al. publication and changes to the PICOST, changes were made to the review protocol. Some of these changes have impacted the search and included studies:
- Changes were made to the search strategy, as many articles were found in the reference lists of included studies and not via the search strategy in the 2017 review. Our review of the search criteria found problematic search terms, which, when removed, the missing papers appeared in the search. To check no other studies were missing, we re-ran the search for the period of the last review (database inception to January 15, 2016) without these terms, and found no new studies from that period. We ran the revised search strategy in MEDLINE and Cochrane Central Register of Controlled Trials on June 18 and October 21,2024.
- Many studies examined dispatcher-assisted CPR (DA-CPR) instructions regardless of whether bystander CPR (B-CPR) was started prior to the emergency call. It was decided to examine the question of DA-CPR together with B-CPR among studies where both were present. Two studies included in the previous B-CPR CoSTR (Olasveengen 2008 914, SOS-Kanto Study Group 2007 920) that had substantial cases of DA-CPR have been moved to this CoSTR.
- The meta-analysis of B-CPR papers in the 2017 review included unadjusted and adjusted data, different study populations, and grouped studies involving B-CPR with and without dispatcher instructions. In this review, all studies that provided data comparing the CPR groups reported imbalances between groups in factors known to influence survival (Goto 2021 408, Javaudin 2021 812, Kitamura 2018 29, Olasveengen 2008 914, SOS-Kanto Study Group 2007 920, Wnent 2021 101). Thus, the review group decided to exclude a previous observational study not reporting adjusted outcomes (Kitamura 2011 3) and to report the included evidence narratively.
Evidence for adult and pediatric literature was sought and considered by the Basic Life Support Adult Task Force and the Pediatric Task Force groups, respectively.
Systematic Review
Cash R, Nehme Z, de Caen A, Perkins G, Dewan M, Dicker B, Dassanayake V, Raffay V, Vaillancourt C, Olasveengen T, Tjelmeland I, Kleinman M, Bray J. Impact of different cardiopulmonary strategies on patient outcomes strategies: A systematic review. In draft.
PICOST
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: Adults in out-of-hospital cardiac arrest.
Intervention: Dispatcher-assisted chest compression-only CPR (CCO-CPR).
Comparators: Dispatcher-assisted conventional CPR (C-CPR) with compressions and ventilations.
Outcomes: Critical: Favourable neurological survival (as measured by cerebral performance category or modified Rankin Score) at discharge or 30-days and at any time interval after 30-days. Important: Survival to discharge or 30 days, Survival to hospital admission, Survival to any time interval after discharge or 30 days survival, Return of spontaneous circulation (ROSC), Quality of life as measured by any indicator or score.
Study Designs: 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) are excluded. Studies without a comparator group, reviews, and pooled analyses were excluded. Observational studies that only reported unadjusted data were also excluded. All relevant publications in any language are included as long as there was an English abstract.
Timeframe: Literature search updated to October 21, 2024.
PROSPERO Registration CRD42024559318
Consensus on Science
After excluding the abovementioned studies, four RCTs (Rea 2010 423, Riva 2024 e010027, Svensson 2010 434) and six observational studies (Goto 2021 408, Javaudin 2021 812, Kitamura 2018 29, Olasveengen 2008 914, SOS-Kanto Study Group 2007 920, Wnent 2021 101) compared dispatcher-assisted compression-only CPR (CCO-CPR) with conventional CPR (C-CPR) at a ratio of 15:2 and/or 30:2 in adults or all ages, with or without bystander-CPR on-going at the time of call. As 15:2 CPR is no longer recommended, all outcomes, including these studies, were downgraded for indirectness. The overall quality of evidence was rated as low to very low for all outcomes primarily due to a very serious risk of bias. The individual observational studies were all at a critical risk of bias due to confounding. Because of this and a high degree of heterogeneity, it was determined that meta-analyses could not be performed.
For the critical outcome of favorable neurological function, we identified one RCT (Rea 2010 423), one observational study limited to only DA-CPR (Goto 2021 408), and three observational studies with combined B-CPR and DA-CPR cases (Javaudin 2021 812, Kitamura 2018 29, SOS-Kanto Study Group 2007 920). Indirect evidence of very-low certainty (downgraded for risk of bias and indirectness) from two cohort studies of combined bystander and DA-CPR suggests favorable neurological function with CCO-CPR compared to 15:2 CPR (adjusted OR 2.22, 95%CI: 1.17 to 4.21; SOS-Kanto Study Group 2007 920) and combined 15:2 and 30:2 CPR (adjusted OR 1.12, 95%CI: 1.06 to 1.19; Kitamura 2018 29). The remaining three studies, including the RCT, reported no difference between the two CPR strategies for survival with good neurological outcomes and either 15:2 CPR (e.g., risk difference 1.50, 95%CI: -1.40 to 4.40; Javaudin 2021 812) or 30:2 CPR (e.g., adjusted OR 0.92, 95%CI: 0.78 to 1.08; Goto 2021 408).
For the critical outcome of survival to hospital discharge or 30 days, we identified low to very-low certainty of evidence (downgraded for risk of bias, imprecision and indirectness) from 2 RCTs (Hallstrom 2000 1546, Svensson 2010 434), both using a 15:2 comparison, and five cohort studies (Goto 2021 408, Javaudin 2021 812, Kitamura 2018 29, Olasveengen 2008 914, Wnent 2021 101). One observational study in 143,500 presumed medical-origin OHCAs of all ages (Kitamura 2018 29) reported significantly higher odds of 30-day survival with CCO-CPR compared to C-CPR of either 15:2 or 30:2 (adjusted OR 1.05, 95%CI: 1.01 to 1.10). Two additional observational studies, one of 5,406 all-aged OHCAs (Wnent 2021 101) and the other of 24,947 adult bystander-witnessed OHCAs (Goto 2021 408), reported significantly lower odds of survival to hospital discharge for CCO-CPR compared to 15:2 and 30:2 CPR (adjusted OR 0.69, 95%CI: 0.53 to 0.90; Wnent 2021 101) and 30-day survival to CCO-CPR compared to 30:2 CPR (adjusted OR 0.72, 95%CI: 0.59, 0.88; Goto 2021 408). The remaining two RCTs and two observational studies reported no differences between the two CPR strategies for survival to hospital discharge (e.g., risk difference 4.20, 95%CI: -1.50 to 9.80; Hallstrom 2000 1546) or 30-day survival (e.g., risk difference 1.70, 95%CI: -1.20 to 4.60; Svensson 2010 434).
For the important outcome of survival to hospital admission, we identified low certainty of evidence (downgraded for imprecision and indirectness) from four RCTs (Hallstrom 2000 1546, Rea 2010 423, Riva 2024 e010027, Svensson 2010 434). Three studies were among adult patients with two comparing CCO-CPR to 15:2 CPR (Hallstrom 2000 1546, Rea 2010 423) and one comparing CCO-CPR to 30:2 CPR (Riva 2024 e010027). The fourth RCT was among all ages, comparing CCO-CPR to 15:2 CPR (Svensson 2010 434). None of the studies reported a significant difference in survival to hospital admission (e.g., risk difference 0.01, 95%CI: -0.57 to 0.07; Riva 2024 e010027).
For the important outcome of ROSC, we identified very-low certainty of evidence (downgraded for risk of bias, imprecision and indirectness) from one cohort study (Kitamura 2018 29). This cohort study of 143,500 presumed medical-origin all-age OHCAs reported no difference in ROSC with CCO-CPR compared to either 15:2 or 30:2 CPR (adjusted 0.99, 95%CI: 0.96, 1.03; Kitamura 2018 29).
Treatment Recommendations
We recommend that dispatchers provide chest compression-only CPR instructions to callers for adults with suspected OHCA (strong recommendation, low-certainty of evidence).
Justification and Evidence to Decision Framework Highlights
In making these recommendations, the task force acknowledged the low-quality evidence, but strongly endorsed the 2020 ILCOR Consensus on Science that all rescuers should perform chest compressions for all patients in cardiac arrest. The task force also considered:
- This topic was prioritized for review due to the age of the previous systematic review which was published in 2017 (Ashoor 2017 112). During that time, a number of additional observational studies were published on the topic.
- Bystander CPR more than doubles OHCA survival (Sasson 2010 63). We placed a higher emphasis on the importance of providing high-quality chest compressions and increasing the overall rate of bystander CPR over providing rescue breaths.
- Increases in rates of bystander CPR and patient outcomes have been reported following the introduction of dispatcher-assisted CCO- or compression-focused CPR in adults (Bray 2011 1393, Iwami 2015 415, Kitamura 2012 2834, Malta Hansen 2015 255). Using a CO-CPR strategy may increase the willingness of bystanders to respond during a cardiac arrest.
- Most bystander CPR for adults is given with DA-CPR instructions, even in the presence of CPR-trained lay-bystanders (Riva 2024 e010027).
- The ongoing TANGO2 (Telephone Assisted CPR. AN evaluation of efficacy amonGst cOmpression only and standard CPR) trial is designed to evaluate whether compression-only cardiopulmonary resuscitation (CPR) by trained laypersons is noninferior to standard CPR in adult out-of-hospital cardiac arrest (NCT03981107). This study will provide additional insight, and likely prompt the task force to revisit this review.
- In making these recommendations, the task force took into consideration heterogeneity in the body of evidence, particularly related to implementation of DA-CPR. Despite this, most included studies suggested either a slight improvement or no difference in patient outcomes for dispatcher-assisted CCO-CPR and C-CPR, regardless of patient population or comparison ratio.
Knowledge Gaps
- What are the identifying key words used by callers that are associated with cardiac arrest?
- Should there be “trigger” words or phrases from the bystander that are so likely to indicate cardiac arrest that the dispatcher can skip parts of the protocol and shorten the time to dispatch and to CPR instruction?
- What is the impact of adherence to or failure to follow dispatch protocols?
- What is the optimal instruction sequence for coaching callers in dispatcher-assisted CPR?
- What is the impact of telephone CPR instructions on non-cardiac etiology arrests such as drowning, trauma, asphyxia in adult and pediatric patients?
- What is the impact of language barriers to performance?
- How many chest compressions should be given, and for how long, before ventilation instructions are introduced?
- Should resuscitation instructions be modified in the context of advanced directives from the victim asking not to be resuscitated?
ETD summary table: BLS 2112 DA CCO vs conventional CPR Et D
References
Ashoor HM, Lillie E, Zarin W, Pham B, Khan PA, Nincic V, Yazdi F, Ghassemi M, Ivory J, Cardoso R, Perkins GD, de Caen AR and Tricco AC. Effectiveness of different compression-to-ventilation methods for cardiopulmonary resuscitation: A systematic review. Resuscitation. 2017;118:112.
Bray JE, Deasy C, Walsh J, Bacon A, Currell A and Smith K. Changing EMS dispatcher CPR instructions to 400 compressions before mouth-to-mouth improved bystander CPR rates. Resuscitation. 2011;82:1393.
Goto Y, Funada A, Maeda T and Goto Y. Dispatcher instructions for bystander cardiopulmonary resuscitation and neurologically intact survival after bystander-witnessed out-of-hospital cardiac arrests: a nationwide, population-based observational study. Crit Care. 2021;25:408.
Hallstrom A, Cobb L, Johnson E and Copass M. Cardiopulmonary resuscitation by chest compression alone or with mouth-to-mouth ventilation. N Engl J Med. 2000;342:1546.
Iwami T, Kitamura T, Kiyohara K and Kawamura T. Dissemination of Chest Compression-Only Cardiopulmonary Resuscitation and Survival After Out-of-Hospital Cardiac Arrest. Circulation. 2015;132:415.
Javaudin F, Raiffort J, Desce N, Baert V, Hubert H, Montassier E, Le Cornec C, Lascarrou JB and Le Bastard Q. Neurological Outcome of Chest Compression-Only Bystander CPR in Asphyxial and Non-Asphyxial Out-Of-Hospital Cardiac Arrest: An Observational Study. Prehosp Emerg Care. 2021;25:812.
Kitamura T, Iwami T, Kawamura T, Nagao K, Tanaka H, Berg RA and Hiraide A. Time-dependent effectiveness of chest compression-only and conventional cardiopulmonary resuscitation for out-of-hospital cardiac arrest of cardiac origin. Resuscitation. 2011;82:3.
Kitamura T, Iwami T, Kawamura T, Nitta M, Nagao K, Nonogi H, Yonemoto N, Kimura T and Japanese Circulation Society Resuscitation Science Study G. Nationwide improvements in survival from out-of-hospital cardiac arrest in Japan. Circulation. 2012;126:2834.
Kitamura T, Kiyohara K, Nishiyama C, Kiguchi T, Kobayashi D, Kawamura T and Iwami T. Chest compression-only versus conventional cardiopulmonary resuscitation for bystander-witnessed out-of-hospital cardiac arrest of medical origin: A propensity score-matched cohort from 143,500 patients. Resuscitation. 2018;126:29.
Malta Hansen C, Kragholm K, Pearson DA, Tyson C, Monk L, Myers B, Nelson D, Dupre ME, Fosbol EL, Jollis JG, Strauss B, Anderson ML, McNally B and Granger CB. Association of Bystander and First-Responder Intervention With Survival After Out-of-Hospital Cardiac Arrest in North Carolina, 2010-2013. Jama. 2015;314:255.
Olasveengen TM, Wik L and Steen PA. Standard basic life support vs. continuous chest compressions only in out-of-hospital cardiac arrest. Acta Anaesthesiol Scand. 2008;52:914.
Rea TD, Fahrenbruch C, Culley L, Donohoe RT, Hambly C, Innes J, Bloomingdale M, Subido C, Romines S and Eisenberg MS. CPR with chest compression alone or with rescue breathing. N Engl J Med. 2010;363:423.
Riva G, Boberg E, Ringh M, Jonsson M, Claesson A, Nord A, Rubertsson S, Blomberg H, Nordberg P, Forsberg S, Rosenqvist M, Svensson L, Andréll C, Herlitz J and Hollenberg J. Compression-Only or Standard Cardiopulmonary Resuscitation for Trained Laypersons in Out-of-Hospital Cardiac Arrest: A Nationwide Randomized Trial in Sweden. Circulation Cardiovascular quality and outcomes. 2024;17:e010027.
Sasson C, Rogers MA, Dahl J and Kellermann AL. Predictors of survival from out-of-hospital cardiac arrest: a systematic review and meta-analysis. Circulation Cardiovascular quality and outcomes. 2010;3:63.
SOS-Kanto Study Group. Cardiopulmonary resuscitation by bystanders with chest compression only (SOS-KANTO): an observational study. Lancet. 2007;369:920.
Svensson L, Bohm K, Castrèn M, Pettersson H, Engerström L, Herlitz J and Rosenqvist M. Compression-only CPR or standard CPR in out-of-hospital cardiac arrest. N Engl J Med. 2010;363:434.
Wnent J, Tjelmeland I, Lefering R, Koster RW, Maurer H, Masterson S, Herlitz J, Böttiger BW, Ortiz FR, Perkins GD, Bossaert L, Moertl M, Mols P, Hadžibegović I, Truhlář A, Salo A, Baert V, Nagy E, Cebula G, Raffay V, Trenkler S, Markota A, Strömsöe A and Gräsner JT. To ventilate or not to ventilate during bystander CPR - A EuReCa TWO analysis. Resuscitation. 2021;166:101.