Mecha CPR: Your Next Air Crew Member!
Transport of patients with ongoing CPR to the correct treatment center is a high risk but potentially lifesaving intervention. Mechanical CPR (mCPR) devices are recommended to reduce risk and maintain chest compression quality. However, such transports have inherent pitfalls to both patient and provider safety. This is a poorly studied field of our practice and no clear consensus for how this should be done exists. In this podcast episode, we are joined by Dr. Per Olav Berve to discuss the practical challenges of these missions, CPR physiology, hemodynamics, and hopefully some hard-earned advice on how to get a patient in cardiac arrest to hospital in a survivable physiologic state.
Listen to Per talk CPR hemodynamics on the EMcrit podcast here.
“I am a consultant anaesthesiologist working full time in Oslo HEMS since 2013. My clinical practice is on two of our five transport platforms; the SAR helicopter (the good old Sea King) of south eastern Norway, where we do land and sea rescue in addition to regular critical care missions, and on the physician manned critical care car in Oslo (a Skoda). I started my anaesthesia training in 2006 and am currently wrapping up a PhD on CPR haemodynamics and physiology, with an emphasis on mechanical CPR devices. My interest for the practicalities of CPR during transport started with our research projects, one of which included autopsy data from 115 cardiac arrest patients, but is now mainly fueled on the intense frustration of me doing it wrong.”
Ondruschka, B., et al. (2018). “Chest compression-associated injuries in cardiac arrest patients treated with manual chest compressions versus automated chest compression devices (LUCAS II) – a forensic autopsy-based comparison.” Forensic Sci Med Pathol 14(4): 515-525.
The aim of this autopsy study was to investigate chest-compression associated injuries to the trunk in out-of-hospital and in-hospital non-traumatic cardiac arrest patients treated with automated external chest compression devices (ACCD; all with LUCAS II devices) versus exclusive manual chest compressions (mCC). In this retrospective single-center study, all forensic autopsies between 2011 and 2017 were included. Injuries following cardiopulmonary resuscitation (CPR) in patients treated with mCC or ACCD were investigated and statistically compared using a bivariate logistic regression. In the seven-year period with 4433 autopsies, 614 were analyzed following CPR (mCC vs. ACCD: n = 501 vs. n = 113). The presence of any type of trunk injury was correlated with longer resuscitation intervals (30 +/- 15 vs. 44 +/- 25 min, p < 0.05). In comparison with mCC, treatment with ACCD led to more frequent skin emphysema (5 vs 0%, p = 0.012), pneumothorax (6 vs. 1%, p = 0.008), lung lesions (19 vs. 4%, p = 0.008), hemopericardium (3 vs 1%, p = 0.025) and liver lesions (10 vs. 1%, p = 0.001), all irrespective of confounding aspects. Higher age and longer CPR durations statistically influenced frequency of sternal and rib fractures (p < 0.001). The mean number of fractured ribs did not vary significantly between the groups (6 +/- 3 vs. 7 +/- 2, p = 0.09). In this cohort with unsuccessful CPR, chest compression-related injuries were more frequent following ACCD application than in the mCC group, but with only minutely increased odds ratios. The severity of injuries did not differ between the groups, and no iatrogenic injury was declared by the forensic pathologist as being fatal. In the clinical routine after successful return of spontaneous circulation a computed tomography scan for CPR-associated injuries is recommended as soon as possible.