The Role of Chest Compressions in Traumatic Cardiac Arrest

Objectives:

• Introduce the ongoing debate over the utility of chest compressions in traumatic cardiac arrest

• Summarize current US guidelines

• Explore the relevant primary literature

• Take-home points

Early in our medical education we are taught the importance of timely initiation of CPR in cardiac arrest and receive certifications in BLS/ACLS. A vital member of a code team is the chest compressor and as a medical student, this vital role often falls to us. However, it was not until my experience as an emergency medicine Sub-I that I learned chest compressions may not always be beneficial to the patient.

There is currently debate in the emergency medicine community on how chest compressions fit into traumatic arrest resuscitation or if they even fit at all.

“In traumatic arrest, in distinction from medical arrest they don’t need to be doing compressions while you’re doing that because compressions aren’t doing anything. So make it easy, tell them to stop CPR for a second to put the damn tube in and be done with it.” -Scott Weingart (1)

"Cardiac arrest resuscitation will likely be ineffective in the presence of uncorrected severe hypovolemia." - American Heart Association

In my personal experience, I found myself doing chest compressions on a trauma patient (gunshot wound to the chest) while an EM resident performed a thoracostomy. As I compressed, I was amazed at her ability to quickly perform the procedure but couldn't help but feel like I was in the way and wondered how or if my chest compressions were benefiting the patient.

Why do we do chest compressions?

Though there has been controversy in the past (thoracic pump vs. cardiac pump)(2) over the exact physiology of how chest compressions work, we perform chest compressions in CPR to propel blood (and oxygen) forward to vital organs (brain, heart) through the increase in intra-thoracic pressure with each compression.(3)

Why would there be an issue with chest compressions in traumatic cardiac arrest (like a penetrating chest wound)?

Common reversible causes of traumatic cardiac arrest, for example hemorrhage/hypovolemia, cannot be reversed or mitigated by increasing intra-thoracic pressure with chest compressions. You need preload and intravascular volume for chest compressions to work!

What do the current guidelines say?

American Heart Association(AHA) CPR and ECG Guidelines: (4,5)

Special Circumstances of Resuscitation – 12. Cardiac arrest associated with trauma

• BLS and ACLS for the trauma patient are fundamentally the same as that for the patient with primary cardiac arrest, with focus on support of airway, breathing, and circulation. However, management of the patient with trauma requires rapid assessment and vigilance for signs of hidden injuries and ongoing hemorrhage.

• Treatment of PEA requires identification and treatment of reversible causes, such as severe hypovolemia, hypothermia, cardiac tamponade, or tension pneumothorax.

• Control ongoing bleeding where possible and replace lost volume if the losses appear to have significantly compromised circulating blood volume.

• Cardiac arrest resuscitation will likely be ineffective in the presence of uncorrected severe hypovolemia.

• Ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT) are treated with CPR and attempted defibrillation.

Advanced Trauma Life Support (ATLS) Guidelines: (6)

Traumatic Circulatory Arrest - defined as trauma patients who are unconscious, have no pulse, PEA (pulseless electrical activity), ventricular fibrillation, asystole

• Start closed CPR simultaneously with ABC management.

• Secure a definitive airway with orotracheal intubation (without rapid sequence induction).

• To alleviate a potential tension pneumothorax, perform bilateral finger or tube thoracostomies.

• According to local policy and the availability of a surgical team skilled in repair of such injuries, a resuscitative thoracotomy may be required if there is no return of spontaneous circulation (ROSC).

• ATLS algorithm included below

Note: Guidelines on resuscitation initiation and termination of resuscitation can be found here.

Currently, neither the ACLS or ATLS guidelines give explicit recommendations on how or if chest compressions should be continued during ongoing hospital resuscitation (e.g. intubation, bilateral thoracostomies, FAST exam) of trauma patients.

Primary Literature Review

There is minimal research evaluating the effectiveness of chest compressions in traumatic cardiac arrest.

Watts S, Smith JE, Gwyther R, Kirkman E. Closed chest compressions reduce survival in an animal model of haemorrhage-induced traumatic cardiac arrest. Resuscitation. May 2019. doi:10.1016/j.resuscitation.2019.04.048 (7).

• Aim: To determine whether chest compressions are beneficial following hemorrhagic-induced TCA and whether resuscitation with blood improves survival compared to crystalloid.

• Method: 39 anesthetized, intubated, sedated pigs underwent controlled hemorrhage (30% blood volume) via right thigh bolt injury until MAP of 45mmhg, were then maintained at MAP of 40 for 60 minutes, and underwent further controlled hemorrhage to MAP of 20mmhg. They were were randomized into groups and received different methods of resuscitation received. Chest compressions were performed by LUCAS and fluid administered at 10ml/kg.

  • Group 1: Chest compressions (CC)

  • Group 2: IV whole blood only (WB)

  • Group 3: IV normal saline only (NS)

  • Group 4: IV whole blood + chest compression (WB + CC)

  • Group 5: IV normal saline + chest compression (NS + CC)

• Primary outcome: Attainment of return of spontaneous circulation (ROSC defined as MAP ≥ 50) within 15 minutes after completion of 3 cycles of resuscitation

• Results: Significant increase of ROSC in groups resuscitated with fluid alone (Gp 2 and 3) than with CCC (Gp 1) (p=0.001). Significant increase of ROSC in group resuscitated with NS alone (Gp 3) than with NS + CCC (5)(p=0.014). No significant difference between group resuscitated with WB alone (Gp2) than with WB + CCC (Gp 4).

• Conclusion: This study supports the rationale that when there is clearly a hemorrhagic pathophysiology, chest compressions should not be performed, and fluid resuscitation with whole blood (or blood component therapy to achieve as close to this as possible) should be initiated.

Luna GK, Pavlin EG, Kirkman T, Copass MK, Rice CL. Hemodynamic effects of external cardiac massage in trauma shock. J Trauma. 1989;29(10):1430-1433. doi:10.1097/00005373-198910000-00022 (8)

• Aim: To determine the hemodynamic effects of external massage in profound shock, hypotension was induced in baboons.

• Method: 3 anesthetized, intubated, sedated baboons each underwent sequential lab-controlled scenarios of tamponade (via pericardial infusion), hypovolemia (via phlebotomy), and cardiac arrest (via barbituate overdose). Arterial pressures and intra-pericardial pressures were measured throughout the experiments and changes in pressures recorded when external chest compressions were performed during each scenario.

• Results: Average augmentation in systolic, diastolic, and MAP by external cardiac compressions decreased in scenarios of hypovolemia and tamponade vs. cardiac arrest. Absolute increment in pressure augmentation markedly less in the presence of hypovolemia.

• Conclusion: External cardiac massage does not produce the hemodynamic changes and potential benefits for trauma victims that are well described and proven in acute cardiogenic shock. Cardiac massage should not delay correction of underlying deficits in shock, inadequate ventricular and intravascular volume.

Our clinical interpretation of these studies' results are limited as both are animal models and have relatively small sample sizes however they help better describe a mechanism of why chest compressions may be ineffective in traumatic cardiac arrest scenarios.

Take-home points: Chest compressions remain a vital part of cardiac arrest resuscitation and should continue to be implemented according to guidelines and local hospital policies. However, there is growing evidence that compressions may be less effective in traumatic arrest. Be aware that chest compressions may hinder a more definitive procedure (e.g. thoracostomy, needle decompression) and plan how your trauma team would handle the scenario.

References

1. Scott Weingart. EMCrit Podcast 36 – Traumatic Arrest. EMCrit Blog. Published on December 4, 2010. Accessed on August 24th 2020. Available at [https://emcrit.org/emcrit/traumatic-arrest/ ]

2. Schlelen, C. L., Berkowitz, I. D., Traystman, R., & Rogers, M. C. (1989). Controversial Issues in Cardiopulmonary Resuscitation. Anesthesiology, 71(1), 133–149. doi:10.1097/00000542-198907000-00022

3. Harris AW, Kudenchuk PJ. Cardiopulmonary resuscitation: the science behind the hands. Heart. 2018;104(13):1056-1061. doi:10.1136/heartjnl-2017-312696

4. Vanden Hoek, T. L., Morrison, L. J., Shuster, M., Donnino, M., Sinz, E., Lavonas, E. J., Jeejeebhoy, F. M., & Gabrielli, A. (2010). Part 12: Cardiac Arrest in Special Situations: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation, 122(18_suppl_3), S829–S861. doi:10.1161/circulationaha.110.971069

5. Lavonas, E. J., Drennan, I. R., Gabrielli, A., Heffner, A. C., Hoyte, C. O., Orkin, A. M., Sawyer, K. N., & Donnino, M. W. (2015). Part 10: Special Circumstances of Resuscitation. Circulation, 132(18 suppl 2), S501–S518. doi:10.1161/cir.0000000000000264

6. ATLS: Advanced Trauma Life Support for Doctors (Student Course Manual). Tenth ed. American College of Surgeons; 2018.

7. Watts S, Smith JE, Gwyther R, Kirkman E. Closed chest compressions reduce survival in an animal model of haemorrhage-induced traumatic cardiac arrest. Resuscitation. May 2019. doi:10.1016/j.resuscitation.2019.04.048

8. Watts S, Smith JE, Gwyther R, Kirkman E. Closed chest compressions reduce survival in an animal model of haemorrhage-induced traumatic cardiac arrest. Resuscitation. May 2019. doi:10.1016/j.resuscitation.2019.04.048

FOAMED Resources

• Allen, Bryant MD. “Traumatic Cardiac Arrest.” EmDOCs.net - Emergency Medicine Education, 21 Apr. 2017, www.emdocs.net/traumatic-cardiac-arrest/.

• "No CPR in Trauma Arrest?" ERcast Lite, 10 Mar. 2015, https://ercast.libsyn.com/no-cpr-in-trauma-arrest.

• Costain, Nick MD. "Management Controversies in Traumatic Cardiac Arrest." EM Ottawa. 12 Apr. 2018, https://emottawablog.com/2018/04/management-controversies-in-traumatic-cardiac-arrest/

Bio:

Kendrick Lang is a 4th year medical student and aspiring emergency physician. After spending a year doing emergency medicine research, he is excited to be back in the hospital and ED.