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: (Vaillancourt and Olasveengen were authors on papers included in the review.)
CoSTR Citation
Olasveengen TM, Semeraro F, Bray J, Smyth M, Vaillancourt C, Kudenchuk P, Masterson S, Johnson N, Norii T, Nehme Z, Ristagno G, Perkins GD, Morley PT -on behalf of the International Liaison Committee on Resuscitation Basic Life Support Task Force.
Minimizing pauses in chest compressions Consensus on Science with Treatment Recommendations [Internet] Brussels, Belgium: International Liaison Committee on Resuscitation (ILCOR) Basic Life Support Task Force, 2022 Jan x. Available from: http://ilcor.org
Methodological Preamble
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 conducted by Olasveengen, Semeraro and Morley with involvement of clinical content experts. Evidence for adult literature was sought and considered by the Basic Life Support Task Force. These data were taken into account when formulating the Treatment Recommendations.
PICOST
The PICOST (Population, Intervention, Comparator, Outcome, Study Designs and Timeframe)
Population: Among adults who are in cardiac arrest in any setting
Intervention: Minimizing of pauses in chest compressions (higher CPR fraction or shorter peri-shock pauses compared to control)
Comparators: Standard CPR (lower CPR fraction or longer peri-shock pauses compared to intervention)
Outcomes: Survival to hospital discharge with good neurological outcome and survival to hospital discharge were ranked as critical outcomes. Return of spontaneous circulation (ROSC) was ranked as an important outcome.
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.
Timeframe: All years and all languages were included as long as there was an English abstract; unpublished studies (e.g., conference abstracts, trial protocols) were excluded. Literature search updated to Dec 17th 2021.
PROSPERO Registration CRD42019154784
NOTE FOR RISK OF BIAS:
Bias was assessed per comparison rather than per outcome, since there were no meaningful differences in bias across outcomes. In cases where differences in risk of bias existed between outcomes this was noted.
Consensus on Science
The evidence identified was categorized into five categories
a) randomized controlled trials designed to evaluate interventions affecting quality of CPR, b) observational studies comparing outcomes before and after interventions designed to improve quality of care (including pauses in chest compressions) or between different systems with differences in chest compression pauses, c) observational studies exploring associations between pauses in chest compressions and outcomes, d) observational studies where outcomes were compared between groups in different chest compression pause categories, and e) observational studies where pauses in compressions were compared between survivors and non-survivors.
The overall quality of evidence was rated as very low for all outcomes primarily due to a very critical risk of bias. The individual studies were all at a critical risk of bias due to confounding. Because of this and a high degree of heterogeneity, no meta-analyses could be performed and individual studies are difficult to interpret.
- Randomized controlled trials designed to evaluate interventions affecting quality of CPR.
For the critical outcomes survival with favourable outcome and survival to discharge or 30 days, we identified very low certainty evidence (downgraded for very serious risk of bias and serious inconsistency) from 3 randomized controlled trials (Beesems 2016, Jost 2010, Nichol 2015) enrolling 25,012 adult out-of-hospital cardiac arrests.
The first trial included 845 patients and evaluated an experimental AED algorithm that observed higher CPR fractions (61% vs. 48%, p<0.001) and shorter pre-shock (9 vs. 19 sec, p<0.001) and post-shock pauses (11 vs. 33, p<0.001) when comparing intervention vs. control. However, there were no significant difference in survival to hospital admission (RR 1.01, 95% CI 0.87 to 1.18 or 1 patient more/1000 survived with the intervention [95% CI, 7 fewer patients/1000 to 6 more patients/1000 survived with the intervention]) or discharge (RR 1.25, 95% CI 0.87 to 1.81 or 2 patients more/1000 survived with the intervention [95% CI, 2 fewer patients/1000 to 7 more patients/1000 survived with the intervention]).(Jost 2010)
The second trial included 23,711 patients and evaluated a continuous chest compression strategy that observed higher CPR fractions (83% vs. 77%, p<0.001) when comparing intervention vs. control (30:2 CPR). While there was lower survival to hospital admission in the intervention group (RR 0.95, 95% CI 0.91 to 0.99 or 2 patients less/1000 survived with the intervention [95% CI, 0 fewer patients/1000 to 2 fewer patients/1000 survived with the intervention]), there was no significant difference in survival to discharge (RR 0.92, 95% CI 0.85 to 1.00 or 1 patients less/1000 survived with the intervention [95% CI, 0 fewer patients/1000 to 2 fewer patients/1000 survived with the intervention]).(Nichol 2015)
The third trial included 456 patients and evaluated an experimental AED algorithm that observed higher CPR fractions (58% vs. 42%, p<0.001) and shorter pre-shock (6 vs. 20 sec, p<0.001) and post-shock pauses (7 vs. 27, p<0.001) when comparing intervention vs. control. However, there were no significant differences in survival to hospital admission (RR 0.95, 95% CI 0.83 to 1.10 or 3 patients fewer/1000 survived with the intervention [95% CI, 12 fewer patients/1000 to 6 more patients/1000 survived with the intervention]) or discharge (RR 1.10, 95% CI 0.88 to 1.38 or 4 patient more/1000 survived with the intervention [95% CI, 75fewer patients/1000 to 13 more patients/1000 survived with the intervention]).(Beesems 2016)
- Observational studies comparing outcomes before and after interventions designed to improve quality of care (including pauses in chest compressions) or between different systems with differences in chest compression pauses
For the critical outcome survival with favourable outcome, we identified very low certainty evidence (downgraded for very serious risk of bias, serious risk of inconsistency and indirectness) from 2 observational studies (Grunau 2018, Olasveengen 2009) in total enrolling 16,122 adult out-of-hospital cardiac arrests. The first study evaluated incremental changes in various CPR quality metrics and outcomes over time, and found that both CPR fraction and proportion of survivors with favourable survival increased from 2006 to 2016 (along with several other quality metrics).(Grunau 2019) The second study compared outcomes for patients treated by a physician-manned ambulance with patients treated with paramedic-manned ambulance, and observed higher CPR fraction (90% vs. 83%, p<0.001) and shorter pre-shock pauses (4 vs. 16 sec, 0<0.001) in patients treated by the physician-manned ambulance, but there were no significant differences in survival with favourable outcome (13% vs. 10%, p=0.38).
For the critical outcome survival to hospital discharge or 30 days, we identified very low certainty evidence (downgraded for very serious risk of bias, serious risk of inconsistency and indirectness) from 3 observational studies (Bleijenberg 2017, Grunau 2018, Olasveengen 2009) in total enrolling 16,246 adult out-of-hospital cardiac arrests. A study comparing outcomes before and after implementation of training and feedback interventions, found improved CPR fraction after intervention (86% vs. 79%, p<0.001), but did not observe any statistically significant difference in survival (20% vs. 15%, p=0.43).(Bleijenberg 2017) A study evaluating incremental changes with time, found CPR fraction increased from 81% to 87% and adjusted risk of discharge rate increased from 8.6% to 16% (p < 0.01 for trend) from the beginning to the end of the observation period (2006-2016).(Grunau 2019) The study comparing cardiac arrests treated by physician- vs. paramedic-manned ambulances observed similar survival to discharge between groups (11% vs. 13%, p=0.28).(Olasveengen 2009)
For the important outcome survival to hospital admission, we identified very low certainty evidence (downgraded for very serious risk of bias, serious risk of inconsistency and indirectness) from 3 observational studies (Bleijenberg 2017, Lakomek 2020, Olasveengen 2009) in total enrolling 1,393 adult out-of-hospital cardiac arrests. A study comparing outcomes before and after implementation of training and feedback interventions, found improved CPR fraction after intervention (86% vs. 79%, p<0.001), but did not observe any statistically significant difference in survival to hospital admission (42% vs. 46%, p=0.59).(Bleijenberg 2017) A study evaluating the effect of CPR monitoring and feedback found an increase in CPR fraction (80% vs. 88%, p<0.001), but no significant difference in the rate of hospital admission (32% vs. 36%, p=0.52).(Lakomek 2020) A study comparing outcomes before and after implementation of system level feedback and targeted training, and observed higher CPR fraction (79% vs. 73%, p=0.007), but no significant differences in survival to hospital admission (12% vs. 12%, p=0.9).(Lyon 2012) The study comparing cardiac arrests treated by physician- vs. paramedic-manned ambulances observed a similar hospital admission rate between groups (25% vs. 28%, p=0.50).(Olasveengen 2009)
For the important outcome ROSC, we identified very low certainty evidence (downgraded for very serious risk of bias, serious risk of inconsistency and indirectness) from 5 observational studies (Grunau 2018, Hostler 2007, Lakomel 2020, Lyon 2012, Olasveengen 2009) enrolling 16,525 adult out-of-hospital cardiac arrests. A study evaluating incremental changes with time, found CPR fraction increased from 81% to 87% and the adjusted rate of ROSC rate increased from 40.7% to 51.4% (p < 0.01 for trend) from the beginning to the end of the observation period (2006-2016).(Grunau 2019) A study evaluating the effect of CPR monitoring and feedback found an increase in CPR fraction (80% vs. 88%, p<0.001), but no significant difference in ROSC (45% vs. 50%, p=46).(Lakomek 2020) A study comparing outcomes before and after implementation of system level feedback and targeted training observed higher CPR fraction (79% vs. 73%, p=0.007), but no significant differences in survival to hospital admission (32% vs. 40%, p=0.56).(Lyon 2012) The study comparing cardiac arrests treated by physician- vs. paramedic-manned ambulances observed similar ROSC between groups (33% vs. 34%, p=0.74).(Olasveengen 2009)
- Observational studies exploring associations between pauses in chest compressions and outcomes
CPR fraction
For the critical outcome survival to discharge or 30 days, we identified very low certainty evidence (downgraded for very serious risk of bias and indirectness, and serious risk of inconsistency) from 4 observational studies (Bouwer 2015, Cheskes 2017, Christenson 2009, Wik 2016) enrolling a total of 18,390 adult out-of-hospital cardiac arrests. Two of these studies found increased CPR fraction to be associated with improved survival (adjusted OR 6.34; 95% CI 1.02-39.5 and OR 1.11; 95% CI 1.01-1.21),(Christenson 2009, Wik 2016) whereas the remaining two did not. (Bouwer 2015, Cheskes 2017)
For the important outcome ROSC, we identified very low certainty evidence (downgraded for downgraded for very serious risk of bias and indirectness, and serious risk of inconsistency) from one observational study enrolling 2,103 adult out-of-hospital cardiac arrests which did not find increasing CPR fraction to be associated with improved survival (adjusted OR 1.05; 95% CI 0.99-1.12).(Vaillancourt 2011)
Peri-shock pauses
For the critical outcome survival to discharge or 30 days, we identified very low certainty evidence (downgraded for very serious risk of bias and indirectness, and serious risk of inconsistency) from 2 observational studies (Bouwer 2015, Cheskes 2017) enrolling 15,887 adult out-of-hospital cardiac arrests. One of these studies found increasing peri-shock pause to be associated with lower survival (adjusted OR for survival 0.85 per 5 min increase; 95% CI 0.77-0.93),(Bouwer 2015) while the other found no significant association between pre-shock pause and survival (adjusted OR for survival 1.07 per 5 sec increase; 95% CI 0.99-1.16).(Cheskes 2017)
- Observational studies where outcomes where compared between groups in dichotomized categories of chest compression fraction and chest compression pause duration
CPR fraction
For the critical outcome survival with favourable outcome, we identified very low certainty evidence (downgraded for very serious risk of bias, serious risk of inconsistency and indirectness) from 1 observational study (Rea 2014) enrolling 446 adult out-of-hospital cardiac arrests which showed higher survival in arrests with CPR fraction >80.4% compared to <80.4% (20% vs. 7%, P=0.015) in the sub-group with 20 minute CPR duration. There were no significant differences in survival based on CPR fraction between the corresponding patient subgroups with 5 or 10 min CPR durations.
For the critical outcome survival to discharge or 30 days, we identified very low certainty evidence (downgraded for very serious risk of bias, serious risk of inconsistency and indirectness) from 5 observational studies (Cheskes 2015, Cheskes 2017, Christenson 2009, Rea 2014, Vaillancourt 2020) enrolling 31,459 adult out-of-hospital cardiac arrests. One study observed higher survival in arrests with CPR fraction >80.4% compared to <80.4% (20% vs. 8%, P=0.032) in the sub-group with 20 minute CPR duration,(Rea 2014) whereas two other studies observed higher adjusted odds ratio for survival in arrests with lower CPR fractions (2.00; 95% CI 1.16-3.32 when <40% was compared to >80%)(Vaillancourt 2020) and lower adjusted odds ratio for survival in higher CPR fractions (0.30; 95% CI 0.20-0.44 and 0.49; 95% CI 0.36-0.68 when <60% was compared to <80% and 60-79%).(Cheskes 2015) There were no significant differences in outcomes in the remaining two studies.(Cheskes 2017, Christenson 2009)
For the important outcome ROSC, we identified very low certainty evidence (downgraded for very serious risk of bias, serious risk of inconsistency and indirectness) from 4 observational studies (Rea 2014, Talikowska 2017, Vaillancourt 2011, Vaillancourt 2020) enrolling 15,679 adult out-of-hospital cardiac arrests. One study observed higher ROSC rates in arrests with CPR fraction >80.4% compared to <80.4% in the sub-group with 10 minute (59% vs. 40%, P=0.004) and 20 minute (40% vs. 18%, P=0.004) CPR duration,(Rea 2014) and another study observed lower adjusted odds ratio for ROSC in arrests with CPR fraction 40-60% (0.83; 95% CI 0.72-0.95) and 60-80% (0.85; 95% CI 0.77-0.94) compared to CPR fraction >80%.(Vaillancourt 2020) A third study observed lower adjusted odds ratio for ROSC with CPR fraction >80 compared to <80% (0.49, 95%CI: 0.28–0.87).(Talikowska 2017) There were no significant differences in outcomes in the remaining study.(Vaillancourt 2011)
Peri-shock pauses
For the critical outcome survival to discharge or 30 days, we identified very low certainty evidence (downgraded for very serious risk of bias, serious risk of inconsistency and indirectness) from 4 observational studies (Cheskes 2011, Cheskes 2014, Cheskes 2015, Cheskes 2017) enrolling 20,400 adult out-of-hospital cardiac arrests. Three of these studies observed higher survival in patients with shorter pre-shock pauses (< 10 sec) compared to longer pre-shock pauses (>10-20 sec), (Cheskes 2011, Cheskes 2014, Cheskes 2015) and two observed higher survival in patients with shorter peri-shock pauses (< 20 sec) compared to longer peri-shock pauses (>20-40 sec). (Cheskes 2011, Cheskes 2015) The largest (15,568 patients), most recent study did not find improved survival with pre-shock pause < 10 sec compared to > 10 seconds in adjusted analysis (adjusted OR 0.86; 95% CI 0.69-1.05).(Cheskes 2017)
- Observational studies where chest compression fraction and pauses in compressions were compared between survivors and non-survivors
CPR fraction
For the critical outcome survival to discharge or 30 days, identified very low certainty evidence (downgraded for very serious risk of bias and indirectness, and serious risk of inconsistency) from 4 observational studies (Brouwer 2015, Cheskes 2011, Cheskes 2014, Wik 2005) enrolling 3,215 adult out-of-hospital cardiac arrests. One study observed higher CPR fractions during the first 5 minutes in non-survivors compared to survivors (74% vs. 71%, p=0.04).(Brouwer 2015) The remaining studies did not observe any differences in CPR fraction between groups.(Cheskes 2011, Cheskes 2014, Wik 2005)
For the important outcome ROSC, we identified very low certainty evidence (downgraded for very serious risk of bias and indirectness, and serious risk of inconsistency) from 4 observational studies (Abella 2005, Talikowska 2017, Uppiretla 2020, Valenzuela 2005) enrolling 607 adult out-of-hospital cardiac arrests. While one study observed higher CPR fractions among those not achieving ROSC in a sub-group of patients with downtimes > 15 minutes (83% vs. 73%, p=0.02),(Talikowska 2017) another study observed significantly higher CPR fractions in patients with ROSC compared to those without ROSC (81% vs. 61%, p=0.001).(Uppiretla 2020) The remaining studies did not observe any differences in CPR fraction between groups. (Abella 2005, Valenzuela 2005)
Treatment Recommendations
We suggest CPR fraction and peri-shock pauses in clinical practice be monitored 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 preshock and postshock pauses in chest compressions be as short as possible (weak recommendation, very-low-certainty evidence).
We suggest the CPR fraction during cardiac arrest (CPR time devoted to compressions) should be as high as possible and at least 60% (weak recommendation, very-low-certainty evidence).
Justification and Evidence to Decision Framework Highlights
This topic was prioritized by the BLS Task Force as the topic had not been reviewed since the 2015 Consensus on Science and Treatment recommendations.
There is general consensus within the resuscitation community is that high quality CPR is important for patient outcomes, and that high quality CPR includes high CPR fraction and short peri-shock pauses. Although the exact targets of these CPR metrics are uncertain, the strong belief in minimizing pauses in compressions (along with physiological rationale in the detrimental effect of no compressions) make prospective clinical trials of long vs. short compression pauses unlikely. The evidence identified in this review was either indirect (in that the interventional studies were developed for related purposes) or observational. Observational studies are challenged by the association between pauses in compressions and good outcome as short resuscitations in patients with shockable rhythms tend to have better outcomes that long resuscitation efforts in non-shockable cardiac arrest patients. The number and proportion of pauses will be dependent on both cardiac rhythm and resuscitation length, and an optimal target will therefore depend on the cardiac arrest characteristics. Shorter resuscitations with a shockable rhythms and recurrent ROSC will be associated with low CPR fractions but good outcome, whereas long resuscitations with asystole will be associated with high CPR fractions but poor outcomes. These factors make interpreting observational data and providing guidance for CPR metrics particularly challenging.
Experimental animal data have to a limited degree explored possible positive effects of post-conditioning (limited pauses in CPR). (Matsuura 2017 8, Segal 2012 1397) There is no human data to inform post-conditioning during cardiac arrest. Weighing a theoretical possibility of positive effects from limited pauses in chest compressions against a certain detrimental effect of lack of chest compressions, it is reasonable to assume low risk of harm from lack of chest compression pauses and that the possibility for desirable effects from fewer pauses outweigh the possible undesirable effects.
The cost or need for resources to implement the intervention is uncertain. Increasing CPR fraction or shorten peri-shock pauses in a resuscitation system will require resources for measuring CPR quality, training and education. However, it is unclear whether the requirements surpass the resources systems already have in place for continued education and training. The task force assessed the resources needed would likely be covered by standard operating costs of high performing systems.
Knowledge Gaps
- No studies directly evaluated a strategy of minimizing pauses in compressions compared to longer pauses in compressions.
- The theoretical benefit from limited pauses in compressions as part of a post-conditioning strategy has not been evaluated in humans.
- Optimal pauses and CPR metrics will depend of patient and cardiac arrest characteristics, there are no studies evaluating specific CPR metric goals for various sub-groups (shockable vs. non-shockable, short vs. longer resuscitations etc).
Attachments
References
References listed alphabetically by first author last name in this citation format (Circulation)
1.Beesems, Stefanie G., Berdowski, Jocelyn, Hulleman, Michiel, Blom, Marieke T., Tijssen, Jan G. P., Koster, Rudolph W.. Minimizing pre- and post-shock pauses during the use of an automatic external defibrillator by two different voice prompt protocols. A randomized controlled trial of a bundle of measures. Resuscitation; 2016.
2.Nichol, G., Leroux, B., Wang, H., Callaway, C. W., Sopko, G., Weisfeldt, M., Stiell, I., Morrison, L. J., Aufderheide, T. P., Cheskes, S., Christenson, J., Kudenchuk, P., Vaillancourt, C., Rea, T. D., Idris, A. H., Colella, R., Isaacs, M., Straight, R., Stephens, S., Richardson, J., Condle, J., Schmicker, R. H., Egan, D., May, S., Ornato, J. P.. Trial of continuous or interrupted chest compressions during CPR. New England Journal of Medicine; 03 Dec 2015.
3.Jost, D., Degrange, H., Verret, C., Hersan, O., Banville, I. L., Chapman, F. W., Lank, P., Petit, J. L., Fuilla, C., Migliani, R., Carpentier, J. P.. DEFI 2005: a randomized controlled trial of the effect of automated external defibrillator cardiopulmonary resuscitation protocol on outcome from out-of-hospital cardiac arrest. Circulation; 2010.
4.Lakomek, F., Lukas, R. P., Brinkrolf, P., Mennewisch, A., Steinsiek, N., Gutendorf, P., Sudowe, H., Heller, M., Kwiecien, R., Zarbock, A., Bohn, A.. Real-time feedback improves chest compression quality in out-of-hospital cardiac arrest: A prospective cohort study. PLoS ONE; 2020.
5.Grunau, B., Kawano, T., Dick, W., Straight, R., Connolly, H., Schlamp, R., Scheuermeyer, F. X., Fordyce, C. B., Barbic, D., Tallon, J., Christenson, J.. Trends in care processes and survival following prehospital resuscitation improvement initiatives for out-of-hospital cardiac arrest in British Columbia, 2006-2016. Resuscitation; April 2018.
6.Bleijenberg, Eduard, Koster, Rudolph W., de Vries, Hendrik, Beesems, Stefanie G.. The impact of post-resuscitation feedback for paramedics on the quality of cardiopulmonary resuscitation. Resuscitation; 2017.
7.Lyon, R. M., Clarke, S., Milligan, D., Clegg, G. R.. Resuscitation feedback and targeted education improves quality of pre-hospital resuscitation in Scotland. Resuscitation; January 2012.
8.Olasveengen, T. M., Lund-Kordahl, I., Steen, P. A., Sunde, K.. Out-of hospital advanced life support with or without a physician: Effects on quality of CPR and outcome. Resuscitation; November 2009.
9.Hostler, D., Rittenberger, J. C., Roth, R., Callaway, C. W.. Increased chest compression to ventilation ratio improves delivery of CPR. Resuscitation; September 2007.
10.Cheskes, Sheldon, Schmicker, Robert H., Rea, Tom, Morrison, Laurie J., Grunau, Brian, Drennan, Ian R., Leroux, Brian, Vaillancourt, Christian, Schmidt, Terri A., Koller, Allison C., Kudenchuk, Peter, Aufderheide, Tom P., Herren, Heather, Flickinger, Katharyn H., Charleston, Mark, Straight, Ron, Christenson, Jim. The association between AHA CPR quality guideline compliance and clinical outcomes from out-of-hospital cardiac arrest. Resuscitation; 2017.
11.Wik, L., Olsen, J. A., Persse, D., Sterz, F., Lozano, M., Brouwer, M. A., Westfall, M., Souders, C. M., Travis, D. T., Herken, U. R., Lerner, E. B.. Why do some studies find that CPR fraction is not a predictor of survival?. Resuscitation; 01 Jul 2016.
12.Brouwer, T. F., Walker, R. G., Chapman, F. W., Koster, R. W.. Association between chest compression interruptions and clinical outcomes of ventricular fibrillation out-of-hospital cardiac arrest. Circulation; 15 Sep 2015.
13.Vaillancourt, C., Everson-Stewart, S., Christenson, J., Andrusiek, D., Powell, J., Nichol, G., Cheskes, S., Aufderheide, T. P., Berg, R., Stiell, I. G.. The impact of increased chest compression fraction on return of spontaneous circulation for out-of-hospital cardiac arrest patients not in ventricular fibrillation. Resuscitation; December 2011.
14.Christenson, J., Andrusiek, D., Everson-Stewart, S., Kudenchuk, P., Hostler, D., Powell, J., Callaway, C. W., Bishop, D., Vaillancourt, C., Davis, D., Aufderheide, T. P., Idris, A., Stouffer, J. A., Stiell, I., Berg, R.. Chest compression fraction determines survival in patients with out-of-hospital ventricular fibrillation. Circulation; September 2009.
15.Vaillancourt, Christian, Petersen, Ashley, Meier, Eric N., Christenson, Jim, Menegazzi, James J., Aufderheide, Tom P., Nichol, Graham, Berg, Robert, Callaway, Clifton W., Idris, Ahamed H., Davis, Daniel, Fowler, Raymond, Egan, Debra, Andrusiek, Douglas, Buick, Jason E., Bishop, T. J., Colella, M. Riccardo, Sahni, Ritu, Stiell, Ian G., Cheskes, Sheldon. The impact of increased chest compression fraction on survival for out-of-hospital cardiac arrest patients with a non-shockable initial rhythm. Resuscitation; 2020.
16.Talikowska, Milena, Tohira, Hideo, Inoue, Madoka, Bailey, Paul, Brink, Deon, Finn, Judith. Lower chest compression fraction associated with ROSC in OHCA patients with longer downtimes. Resuscitation; 2017.
17.Cheskes, Sheldon, Schmicker, Robert H., Rea, Tom, Powell, Judy, Drennan, Ian R., Kudenchuk, Peter, Vaillancourt, Christian, Conway, William, Stiell, Ian, Stub, Dion, Davis, Dan, Alexander, Noah, Christenson, Jim. Chest compression fraction: A time dependent variable of survival in shockable out-of-hospital cardiac arrest. Resuscitation; 2015.
18.Rea, Thomas, Olsufka, Michele, Yin, Lihua, Maynard, Charles, Cobb, Leonard. The relationship between chest compression fraction and outcome from ventricular fibrillation arrests in prolonged resuscitations. Resuscitation; 2014.
19.Cheskes, Sheldon, Schmicker, Robert H., Verbeek, P. Richard, Salcido, David D., Brown, Siobhan P., Brooks, Steven, Menegazzi, James J., Vaillancourt, Christian, Powell, Judy, May, Susanne, Berg, Robert A., Sell, Rebecca, Idris, Ahamed, Kampp, Mike, Schmidt, Terri, Christenson, Jim. The impact of peri-shock pause on survival from out-of-hospital shockable cardiac arrest during the Resuscitation Outcomes Consortium PRIMED trial. Resuscitation; 2014.
20.Cheskes, S., Schmicker, R. H., Christenson, J., Salcido, D. D., Rea, T., Powell, J., Edelson, D. P., Sell, R., May, S., Menegazzi, J. J., Van Ottingham, L., Olsufka, M., Pennington, S., Simonini, J., Berg, R. A., Stiell, I., Idris, A., Bigham, B., Morrison, L.. Perishock pause: An independent predictor of survival from out-of-hospital shockable cardiac arrest. Circulation; 05 Jul 2011.
21.Uppiretla, A. K., G, M. G., Rao, S., Don Bosco, D., S, M. S., Sampath, V.. Effects of Chest Compression Fraction on Return of Spontaneous Circulation in Patients with Cardiac Arrest; a Brief Report. Advanced Journal of Emergency Medicine; 2020.
22.Wik, L., Kramer-Johansen, J., Myklebust, H., Sorebo, H., Svensson, L., Fellows, B., Steen, P. A.. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest. Journal of the American Medical Association; 19 Jan 2005.
23.Valenzuela, T. D., Kern, K. B., Clark, L. L., Berg, R. A., Berg, M. D., Berg, D. D., Hilwig, R. W., Otto, C. W., Newburn, D., Ewy, G. A.. Interruptions of chest compressions during emergency medical systems resuscitation. Circulation; 2005.
24.Abella, B. S., Alvarado, J. P., Myklebust, H., Edelson, D. P., Barry, A., O'Hearn, N., Vanden Hoek, T. L., Becker, L. B.. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest. Journal of the American Medical Association; 19 Jan 2005.