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: Laurie Morrison, Christian Vaillancourt
CoSTR Citation
Bray J, Cash R, Nehme Z, Dicker B, de Caen A, Perkins G, Dewan M, Dassanayake V, Raffay V, Vaillancourt C, Tjelmeland I, Kleinman M, Olasveengen T on behalf of the International Liaison Committee on Resuscitation (ILCOR) Basic Life Support Task Force. Continuous chest compressions versus standard cardiopulmonary resuscitation for in-hospital CPR: A systematic review Consensus on Science with Treatment Recommendations [Internet] Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) Basic Life Support Task Force, November 21 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 led by the Basic Life Support Task Force (Ashoor 2017 112) and conducted by the Knowledge Synthesis Unit at St Michael’s Hospital, Toronto, Canada with involvement of clinical content experts. The review team examined the Ashoor at al. 2017 systematic review and noted a high number of studies that were not identified in the search strategy used. Additionally, the Ashoor review included unadjusted data and some meta-analyses that had considerable heterogeneity.
For the present review, the team revised and re-executed the search strategy from database inception to October 20, 2024. Evidence for adult and pediatric literature was sought and considered by the Basic and Paediatric Life Support Task Forces. Since that time, additional scientific literature was published after the completion of the systematic review and identified by the Basic Life Support Task Force and is described before the justifications and evidence to decision highlights section of this CoSTR. These data were considered when formulating the Treatment Recommendations. The current review also excluded studies reporting unadjusted data and meta-analyses were reconsidered where there was significant heterogeneity between included studies.
Systematic Review
Cash R, Nehme Z, Dicker B, de Caen A, Perkins G, Dewan M, 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. Compression and ventilation strategies in cardiopulmonary resuscitation: A systematic review [in progress]
PICOST
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: Adults and children with cardiac arrest in any setting (out-of-hospital or in-hospital)
Intervention: Continuous chest compressions with or without ventilations delivered by in-hospital providers
Comparators: Standard CPR, defined as any compression-to-ventilation ratio delivered by in-hospital providers. Comparator groups that received no CPR or compared manual CPR with mechanical CPR were excluded from the review. Studies including automated CPR or any use of mechanical devices were only included if administered to all treatment arms.
Outcomes: 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; Survival to discharge or 30 days survival; 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 was conducted from database inception to October 20, 2024
PROSPERO Registration CRD42024559318
Consensus on Science
The search strategy was conducted in Medline and the Cochrane Central Register of Controlled Trials. The broader search identified 11,442 non-duplicate titles, of which 1 study (Lee 2013 158) included in the previous Ashoor 2017 systematic review was also included here.
The included single-center cohort study evaluated the effect of continuous mechanical chest compressions in patients admitted to an emergency department following OHCA.(Lee 2013 158) The application of the mechanical CPR device and airway placement occurred simultaneously, and the authors describe both typically occur within 30 second of arrival. In this study, positive pressure ventilation without interruption of chest compressions after tracheal intubation was compared with interruption of chest compressions for one ventilation after every fifth chest compression (a CV ratio of 5:1) among patients admitted to a hospital emergency department after OHCA. Chest compressions were delivered by a mechanical device known as the Thumper Mechanical CPR Machine (Michigan Instruments, Grand Rapids, MI) in all patients, a device that is not commonly used clinically and that delivered different average compression rates (70 versus 100 per minute) between the study periods. The study compared continuous chest compressions and ventilations delivered after every 10th compression (without pausing compressions) with a 5:1 CV ratio (with pauses for ventilation) that resulted in more frequent pauses in compressions and higher overall ventilation rates than the conventional 30:2 CV ratio recommended by the 2015 CoSTR.(Perkins 2015 e43, Travers 2015 S51)
Favourable neurological survival at discharge or 30-days
No adjusted data was reported.
Survival at discharge or 30-days
For the critical outcome of survival, we identified very-low certainty evidence (downgraded for risk of bias and very serious imprecision) from one cohort study.(Lee 2013 158) In the adjusted analysis, patients who received mechanical chest compressions and tracheal intubation with positive pressure ventilations without pausing chest compressions had increased adjusted survival to hospital discharge (adjusted odds ratio [aOR] = 2.43, 95%CI: 1.15 to 5.12) when compared to those who received mechanical chest compressions interrupted for ventilations at a ratio of 5 compressions to 1 ventilation.
Return of spontaneous circulation (ROSC)
For the critical outcome of return of spontaneous circulation, we identified very-low certainty evidence (downgraded for risk of bias and very serious imprecision) from one cohort study.(Lee 2013 158) In the adjusted analysis, patients who received mechanical chest compressions and tracheal intubation with positive pressure ventilations without pausing chest compressions had increased return of spontaneous circulation (adjusted odds ratio [aOR] = 1.62, 95%CI: 1.07 to 2.43) when compared to those who received mechanical chest compressions interrupted for ventilations at a ratio of 5 compressions to 1 ventilation.
Treatment Recommendations
In-hospital providers should perform CPR with 30 compressions to 2 ventilations or continuous chest compressions with positive pressure ventilations delivered without pausing chest compressions in adults in cardiac arrest (Good Practice Statement).
Justification and Evidence to Decision Framework Highlights
- Interruptions in chest compressions have been associated with poorer clinical outcomes in observational studies.(Christenson 2009 1241) Pauses for ventilations are a significant source of interruptions in chest compressions and may negatively impact coronary and aortic blood flow.(Berg 2001 2465) Asynchronous positive pressure ventilation may achieve similar oxygenation without compromising chest compression quality.
- This topic was prioritised for review due to the time since the previous systematic review.(Ashoor 2017 112)
- The only study (Lee 2013 158) that examined this PICOST was conducted with a before-and-after design that, although adjusted for demographic and cardiac arrest characteristics, did not account for potential temporal differences in resuscitation efficiencies between study periods. In addition to the adjusted data presented above, the included study reported no demonstrable benefit for unadjusted favourable neurological function (1.6% [5/307] vs. 1.9% [4/208], p=0.80) when compared to those who received mechanical chest compressions interrupted for ventilations at a ratio of 5 compressions to 1 ventilation.(Lee 2013 158)
- The good practice statement for practice before an advanced airway is placed was added to fill the treatment gap and provide guidance for immediate CPR.
- Data on the same question in EMS found no high-quality evidence to support the superiority of either CCC or standard CPR for patient outcomes in OHCA. The task force also placed high-value on providing consistent recommendations for EMS and in-hospital providers. One large high-quality RCT in EMS reported no difference in patient outcomes with ventilations at a rate of 10/min without pausing compressions compared with a 30:2 ratio before intubation.(Nichol 2015 2203)
- The task force also placed a relatively high value on providing high-quality chest compressions and simplifying resuscitation logistics for providers. It also noted support for the clinical benefit of bundles of care involving minimally interrupted cardiac resuscitation. Evidence suggests that a CV ratio of 30:2 may be much harder to achieve in practice and would ultimately result in asynchronous ventilations.(Schmicker 2021 31)
- Future reviews should also include EMBASE in the search strategy.
Knowledge Gaps
Several knowledge gaps were identified in the review of this topic, including:
1. Are continuous chest compressions with or without ventilations delivered by in-hospital providers comparable to standard CPR?
2. What is the effect of delayed positive pressure ventilation versus 30:2 high-quality CPR?
3. How effective is passive oxygenation during resuscitation?
4. How does adherence to compression-only CPR or a CV ratio of 30:2 influence patient outcomes?
EtD Table: BLS 2222 In hospital CCO vs standard CPR Et D
References
Ashoor, H. M., E. Lillie, W. Zarin, B. Pham, P. A. Khan, V. Nincic, F. Yazdi, M. Ghassemi, J. Ivory, R. Cardoso, G. D. Perkins, A. R. de Caen, A. C. Tricco and I. B. L. S. T. Force (2017). "Effectiveness of different compression-to-ventilation methods for cardiopulmonary resuscitation: A systematic review." Resuscitation 118: 112.
Lee, I. H., C. K. How, W. H. Lu, Y. M. Tzeng, Y. J. Chen, C. H. Chern, W. F. Kao, D. H. Yen and M. S. Huang (2013). "Improved survival outcome with continuous chest compressions with ventilation compared to 5:1 compressions-to-ventilations mechanical cardiopulmonary resuscitation in out-of-hospital cardiac arrest." J Chin Med Assoc 76(3): 158.
Nichol, G., B. Leroux, H. Wang, C. W. Callaway, G. Sopko, M. Weisfeldt, I. Stiell, L. J. Morrison, T. P. Aufderheide, S. Cheskes, J. Christenson, P. Kudenchuk, C. Vaillancourt, T. D. Rea, A. H. Idris, R. Colella, M. Isaacs, R. Straight, S. Stephens, J. Richardson, J. Condle, R. H. Schmicker, D. Egan, S. May, J. P. Ornato and R. O. C. Investigators (2015). "Trial of Continuous or Interrupted Chest Compressions during CPR." N Engl J Med 373(23): 2203.
Perkins, G. D., A. H. Travers, R. A. Berg, M. Castren, J. Considine, R. Escalante, R. J. Gazmuri, R. W. Koster, S. H. Lim, K. J. Nation, T. M. Olasveengen, T. Sakamoto, M. R. Sayre, A. Sierra, M. A. Smyth, D. Stanton, C. Vaillancourt and C. Basic Life Support Chapter (2015). "Part 3: Adult basic life support and automated external defibrillation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations." Resuscitation 95: e43.
Schmicker, R. H., G. Nichol, P. Kudenchuk, J. Christenson, C. Vaillancourt, H. E. Wang, T. P. Aufderheide, A. H. Idris and M. R. Daya (2021). "CPR compression strategy 30:2 is difficult to adhere to, but has better survival than continuous chest compressions when done correctly." Resuscitation 165: 31.
Travers, A. H., G. D. Perkins, R. A. Berg, M. Castren, J. Considine, R. Escalante, R. J. Gazmuri, R. W. Koster, S. H. Lim, K. J. Nation, T. M. Olasveengen, T. Sakamoto, M. R. Sayre, A. Sierra, M. A. Smyth, D. Stanton, C. Vaillancourt and C. Basic Life Support Chapter (2015). "Part 3: Adult Basic Life Support and Automated External Defibrillation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations." Circulation 132(16 Suppl 1): S51.