IT ALL STARTED WITH A PLUNGER

apple-touch-icon-144x144Anesthesia and Analgesia just published a superb review on the current edge of CPR. But everything started with a plunger. Yup! A plunger ! In the late eighties, a son resuscitated his father with the help of a plunger. Poorly accustomed to standard CPR, he snapped a plunger to his father’s chest. This strategy may have amplified the chest decompression and he successfully resuscitated his father.

This story was told in 1990 in the JAMA by Keith Lurie. Frank Zappa once said that without deviation from the norm, there is no progress. I think that we have got a nice illustration here!

Back in the now, CPR has evolved, but most of us are still practising in the dark ages. Recently the same Keith Lurie has published a superb review of current advances and the physiology of cardio-pulmonary resuscitation in Anesthesia & Analgesia. It is a must read for anyone interested in the finer points of CPR!

Compression depth and rate

Most of us think we know CPR. It’s a basic emergency skill. But frankly, I learned a lot reading this article. There are many concepts, and many tips and tricks on CPR and common errors in CPR that makes the article worth reading, but of recent advances, there are three main ideas I focused on :

ACD ITD

an active compression decompression device (ACD) is useful when used properly. This device has lost its sex-appeal with large studies with mixed results. According to the authors of the CPR physiology review (involved in ACD design), there are a lot of heterogeneity in practice and the outcome may be skewed. To me, it is physically harder to deliver CPR with an ACD, than standard CPR. This might explain some discrepancies in studies. The authors also underscore the complementary effect of the ACD with an ITD.

an impedance threshold device (ITD) limits the cardio-pulmonary interactions especially during positive pressure ventilation. Its goal it to impedes airflow during the the recoil phase of the thorax. This way, the intrathoracic pressure is kept low and the venous return to the thorax is increased instead of air influx to the lungs.

the supine position might not be the optimal position to perform CPR, head-up CPR is a promising research path. Experimental research in animals has shown that an head-up CPR might decrease intracranial pressure and increase venous return. Both could limit hypoxic brain injury with the hope of a substantial outcome benefit. I guess that this strategy needs some feasibility studies first…

The article adds a lot more gold than this short synopsis and also gives a good summary of the common errors during CPR and new insights into anticipation of the post-resuscitation phase.

I also like the parallel made at the end of the article about complex diseases and the need for a bundle to fight cardiac arrest. Keith Lurie writes : “In the case of HIV, 3 drugs found to be ineffective alone were shown to be highly effective when combined”. L’union fait la force!

My personal conclusion after reading this article is that CPR deserves more attention. It’s difficult to be super-optimistic with the low survival rates and poor neurologic outcomes, but seeing the glass half full, I’d say that there’s still a lot to be implemented in every day practice that might lead to many more patients being successfully resuscitated.

The Physiology of Cardiopulmonary Resuscitation, Lurie et al, Anesth Analg, Nov 2015.

CPR: the P stands for plumber’s helper, Lurie, JAMA 1990.

PS. COI: Lurie has been developing the ResCuePod, and might have a more positive take on ACD/ITD than most. But don’t let that distract you from this great article of CPR physiology.

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