Chest Compression Interruptions During Cardiopulmonary Resuscitation: Causes, Consequences and Minimization Strategies

High-quality cardiopulmonary resuscitation (CPR) is a crucial element for improving survival chances of cardiac arrest patients. Over the past decades, numerous studies have demonstrated the importance of minimizing chest compression interruptions to optimize coronary and cerebral perfusion. However, despite recommendations from scientific societies, chest compression interruptions remain frequent during cardiac arrest management, both in hospital and out-of-hospital settings.

 

This article aims to review the main causes of chest compression interruptions during CPR, their consequences on patient prognosis, as well as strategies to minimize them. We will rely on recent literature data, particularly from large-scale observational studies.

 

Epidemiology and Prognostic Impact of Interruptions

 

Frequency of Interruptions

Several observational studies have quantified the frequency and duration of chest compression interruptions during CPR. In a large retrospective study conducted in Seattle on 3,601 out-of-hospital cardiac arrests between 2007 and 2016, Hanisch et al. analyzed a total of 74,584 minutes of CPR[1]. They identified 30,043 pauses in chest compressions, representing 6,621 minutes, or 8.9% of the total resuscitation duration. The median duration of interruptions per case was 83 seconds (interquartile range [IQR] 46-145 seconds).

Another observational study conducted in Belgium by Dewolf et al. on 206 in- and out-of-hospital resuscitations recorded 1,867 compression interruptions, of which 623 lasted more than 10 seconds[2]. In 4.3% of cases, interruptions exceeded 60 seconds.

These figures show that chest compression interruptions remain frequent despite recommendations, with a significant impact on the total chest compression fraction.

Impact on Prognosis

Numerous studies have demonstrated an association between the duration of chest compression interruptions and the prognosis of cardiac arrest patients.

In an observational study including 319 out-of-hospital cardiac arrests, Brouwer et al. showed that a 5-second increase in the longest pause was associated with a significant decrease in survival chances (odds ratio [OR] 0.89; 95% confidence interval [CI] 0.83-0.95)[3]. This negative association was observed for both defibrillation-related pauses (OR 0.85; 95% CI 0.77-0.93) and other causes of pauses (OR 0.83; 95% CI 0.75-0.91).

Furthermore, Christenson et al. demonstrated that the chest compression fraction (defined as the percentage of time during which compressions are performed) was an independent predictive factor for survival in patients with ventricular fibrillation[4]. A 10% increase in the compression fraction was associated with a 1.11 (95% CI 1.01-1.21) increase in survival chances.

These data underline the importance of minimizing chest compression interruptions to optimize survival chances for cardiac arrest patients.

 

Main Causes of Chest Compression Interruptions

Cardiac Rhythm Analysis and Defibrillation

Cardiac rhythm analysis and defibrillation constitute the main cause of chest compression interruptions during CPR. In Hanisch et al.’s study, manual rhythm analysis and pulse checks accounted for 41.6% of the total interruption time, with a median duration of 8 seconds (IQR 5-12 seconds) per interruption[1]. Automated analysis by automated external defibrillator (AED) represented 13.7% of interruption time, with a median duration of 17 seconds (IQR 13-23 seconds).

Dewolf et al. also identified rhythm analysis and pulse checks as the main cause of prolonged interruption (>10 seconds), accounting for 51.6% of pauses[2].

These interruptions are necessary to allow reliable rhythm analysis without compression-related artifacts. However, their duration can be optimized through various strategies:

– Precharging the defibrillator during compressions

– Immediate resumption of compressions after shock, without rhythm verification

– Development of rhythm analysis algorithms during compressions

Airway Management

Airway management, particularly endotracheal intubation, is another frequent cause of prolonged compression interruptions. In Hanisch et al.’s study, intubation attempts accounted for 5.3% of total interruption time, with a median duration of 19 seconds (IQR 11-35 seconds)[1].

Wang et al. specifically studied the impact of prehospital intubation on CPR interruptions[5]. Out of 100 analyzed cardiac arrests, intubation was responsible for 25% of compression interruptions, with an average duration of 46.5 seconds per attempt (95% CI 40.0-53.0 seconds).

It’s important to note that the proportion of cases with interruption for intubation decreased over time in Hanisch et al.’s study, from 33.5% in 2007 to 16.7% in 2016 (p<0.0001)[1]. This suggests an improvement in practices, with an increasing ability to intubate without interrupting compressions.

Changing Compression Providers

Fatigue of the rescuer performing chest compressions requires regular provider changes, typically every 2 minutes. This change can be a source of interruptions if poorly coordinated.

In a study on pediatric in-hospital cardiac arrests, Sutton et al. showed that provider changes were responsible for 41% of the total compression interruption time[6].

Vascular Access

Establishing vascular access can also be a source of compression interruptions, especially in case of difficulty. In Hanisch et al.’s study, central venous line placement was associated with prolonged interruptions (median 32 seconds, IQR 17-77 seconds) but was infrequent (58 cases out of 3,601)[1].

The increasing use of intraosseous devices has helped reduce interruptions related to vascular access. Reades et al. showed that the median time to obtain tibial intraosseous access was significantly shorter than for peripheral venous access (4.6 vs 5.8 minutes, p<0.001)[7].

Other Causes

Other less frequent causes of interruption have been reported:

– Patient movement

– Installation of mechanical chest compression devices

– Cardiac ultrasound

– Performing coronary angiography

 

Temporal Evolution and Impact of Improvement Strategies

Several studies have shown a progressive improvement in the chest compression fraction over time, demonstrating the effectiveness of training strategies and practice optimization.

In Hanisch et al.’s 10-year study, the median total interruption duration per case decreased from 115 seconds in 2007 to 72 seconds in 2016 (p<0.0001)[1]. The median duration of individual interruptions also decreased, from 14 to 7 seconds (p<0.0001). This improvement was observed for most causes of interruption, notably manual rhythm analysis (11 vs 7 seconds, p<0.001) and AED analysis (22 vs 14 seconds, p<0.001).

These advances are the result of various implemented strategies:

1. 1. 1. Training in high-performance CPR
      2. Optimization of defibrillator interface (e.g., precharging during compressions)
      3. Coordination of interventions (e.g., provider rotation during rhythm analysis)
      4. Performing certain procedures without interrupting compressions (intubation, line placement)

The impact of these strategies is illustrated by the improvement in chest compression fraction, increasing from <80% in Resuscitation Outcomes Consortium studies in 2009-2011 to >85% in Hanisch et al.’s study[1,4].

 

Strategies to Minimize Interruptions

Rhythm Analysis and Defibrillation

Several strategies can reduce interruptions related to rhythm analysis and defibrillation:

1. 1. 1. Defibrillator precharging: Edelson et al. showed that precharging the defibrillator during compressions reduced the median pre-shock pause duration from 9 to 2 seconds (p<0.001)[8].

1. 1. 2. Immediate resumption of compressions after shock: Current recommendations advocate immediate resumption of compressions after shock, without rhythm or pulse check.

1. 1. 3. Analysis during compressions: Algorithms allowing rhythm analysis during compressions are in development. Berger et al. showed that an artifact reduction system could correctly identify ventricular fibrillation in 97% of cases during compressions[9].

1. 1. 4. “Hands-on defibrillation”: This technique involves continuing compressions during shock delivery. Although controversial, a study by Lloyd et al. showed that the leakage current measured in the rescuer was below electrical safety standards[10].

Airway Management

To limit interruptions related to airway management:

1. 1. 1. Initially prioritize passive oxygenation or mask ventilation
      2. If intubation is necessary, perform it without interrupting compressions
      3. Use supraglottic devices as an alternative to intubation
      4. Train teams in intubation during compressions

Changing Compression Providers

The change of provider for compressions should be anticipated and coordinated:

1. 1. 1. Use a timer to anticipate the change every 2 minutes
      2. Perform the change during rhythm analysis
      3. Train teams for rapid and smooth provider changes

Vascular Access

To limit interruptions related to vascular access:

1. 1. 1. Prioritize intraosseous access in case of difficulty with peripheral venous access
      2. Perform line placement without interrupting compressions
      3. Defer central line placement to a later phase if necessary

Other Strategies

Other strategies can help minimize interruptions:

1. 1. 1. Use of mechanical chest compression devices for transport
      2. Performing cardiac ultrasound without interrupting compressions
      3. Training teams in high-performance CPR with role assignment
      4. Post-resuscitation debriefing with analysis of interruptions

Future Perspectives

Despite progress made, additional efforts are needed to further optimize the chest compression fraction during CPR. Several promising research and development axes include:

1. 1. 1. Rhythm analysis during compressions
      2. Artificial intelligence and decision support
      3. Real-time feedback devices
      4. Simulation training
      5. Optimization of resuscitation protocols

 

Conclusion

Chest compression interruptions during CPR remain frequent despite recommendations, with a demonstrated negative impact on the prognosis of cardiac arrest patients. The main causes are rhythm analysis, defibrillation, airway management, and provider changes.

Significant progress has been made in recent years, with a progressive reduction in the duration of interruptions and an improvement in the chest compression fraction. These advances are the result of training strategies and practice optimization.

Continued research and training efforts are necessary to move towards the goal of truly uninterrupted CPR. The development of new technologies, such as rhythm analysis during compressions, could allow a new milestone in minimizing interruptions.

 

 

References

 

1. Hanisch JR, Counts CR, Latimer AJ, et al. Causes of Chest Compression Interruptions During Out-of-Hospital Cardiac Arrest Resuscitation. J Am Heart Assoc. 2020;9(6):e015599. doi:10.1161/JAHA.119.015599

 

2. Dewolf P, Wauters L, Clarebout G, et al. Assessment of chest compression interruptions during advanced cardiac life support. Resuscitation. 2021;165:140-147. doi:10.1016/j.resuscitation.2021.06.022

 

3. Brouwer TF, Walker RG, Chapman FW, Koster RW. Association Between Chest Compression Interruptions and Clinical Outcomes of Ventricular Fibrillation Out-of-Hospital Cardiac Arrest. Circulation. 2015;132(11):1030-1037. doi:10.1161/CIRCULATIONAHA.115.014016

 

4. Christenson J, Andrusiek D, Everson-Stewart S, et al. Chest compression fraction determines survival in patients with out-of-hospital ventricular fibrillation. Circulation. 2009;120(13):1241-1247. doi:10.1161/CIRCULATIONAHA.109.852202

 

5. Wang HE, Simeone SJ, Weaver MD, Callaway CW. Interruptions in cardiopulmonary resuscitation from paramedic endotracheal intubation. Ann Emerg Med. 2009;54(5):645-652.e1. doi:10.1016/j.annemergmed.2009.05.024

 

6. Sutton RM, Maltese MR, Niles D, et al. Quantitative analysis of chest compression interruptions during in-hospital resuscitation of older children and adolescents. Resuscitation. 2009;80(11):1259-1263. doi:10.1016/j.resuscitation.2009.08.009

 

7. Reades R, Studnek JR, Vandeventer S, Garrett J. Intraosseous versus intravenous vascular access during out-of-hospital cardiac arrest: a randomized controlled trial. Ann Emerg Med. 2011;58(6):509-516. doi:10.1016/j.annemergmed.2011.07.020

 

8. Edelson DP, Robertson-Dick BJ, Yuen TC, et al. Safety and efficacy of defibrillator charging during ongoing chest compressions: a multi-center study. Resuscitation. 2010;81(11):1521-1526. doi:10.1016/j.resuscitation.2010.07.014

 

9. Berger RD, Palazzolo J, Halperin H. Rhythm discrimination during uninterrupted CPR using motion artifact reduction system. Resuscitation. 2007;75(1):145-152. doi:10.1016/j.resuscitation.2007.02.025

 

10. Lloyd MS, Heeke B, Walter PF, Langberg JJ. Hands-on defibrillation: an analysis of electrical current flow through rescuers in direct contact with patients during biphasic external defibrillation. Circulation. 2008;117(19):2510-2514. doi:10.1161/CIRCULATIONAHA.107.763011

 

11. Coult J, Blackwood J, Sherman L, Rea TD, Kudenchuk PJ, Kwok H. Ventricular fibrillation waveform analysis during chest compressions to predict survival from cardiac arrest. Circ Arrhythm Electrophysiol. 2019;12(1):e006924. doi:10.1161/CIRCEP.118.006924

 

12. Kirkbright S, Finn J, Tohira H, Bremner A, Jacobs I, Celenza A. Audiovisual feedback device use by health care professionals during CPR: a systematic review and meta-analysis of randomised and non-randomised trials. Resuscitation. 2014;85(4):460-471. doi:10.1016/j.resuscitation.2013.12.012

 

13. Cheskes S, Schmicker RH, Verbeek PR, et al. The impact of peri-shock pause on survival from out-of-hospital shockable cardiac arrest during the Resuscitation Outcomes Consortium PRIMED trial. Resuscitation. 2014;85(3):336-342. doi:10.1016/j.resuscitation.2013.10.014