Out of Hospital Cardiac Arrest - Part 2

The UC Division of EMS has recorded a series of podcasts to celebrate EMS Week 2016.  We are honored to be able to engage EMS Providers throughout the world with this forum.  If you practice pre-hospital medicine, we would like to say thank you and that we appreciate everything you do to provide a high level of care to ill and injured patients in a wide variety of austere environments.  For this podcast, we were joined by Dr. Dustin Calhoun, Associate Director of the UC Division of EMS, as well as two of this year’s UC EMS Fellows, Dr. Mike Bohanske and Dr. Justin Benoit.

This part takes a look at the planning components of CPR, ventilation management, and medications associated with the management of cardiac arrest. While it’s crucial to focus on the basic components of the out of hospital cardiac arrest (OHCA) management, providers must utilize critical thinking and organized thought processes to increase the likelihood of success. 

Preplanning is not a new concept for public safety. Fire, law enforcement, and EMS work together to preplan their response to large campuses, critical infrastructures, and other potential disasters. OHCA management is something that EMS providers are more likely to encounter yet less likely to preplan for. While responding to a fire scene, tasks are delegated out to efficiently coordinate their attack. While responding to an OHCA, providers should know who’s going to be the first one on the chest, who’s going to manage the airway, who’s going to obtain vascular access, etc. Preplanning and coordination can organize the overall scene and make the management run much smoother. 

When everyone knows their role in a cardiac arrest, this allows the senior provider to take a step back and perform an overall assessment of the patient. This situational awareness can open up potential treatment modalities or even initiate the consideration that the patient may be one of the few patients who would benefit from transport to the ED during OHCA instead of working the arrest on scene. 

During cardiac arrest management, both in and out of hospital, many providers have issues with delivering the appropriate rate and tidal volume. One consideration, with an advanced airway in place, is to deliver one ventilation every 10 compressions. By timing the ventilation delivery with the compressions the ventilator will sync their timing with the compressor helping everyone stay on the same track. Providers can also reduce the tidal volume by either squeezing an adult BVM with their middle finger, index finger, and thumb or they can consider replacing the adult bag with a pediatric bag. This reduction in rate and volume helps decrease intrathoracic pressure and increase coronary perfusion. 

Over the past few guideline changes, some medications have stayed constant while other medications have fallen to the side. In the 2015 guidelines, vasopressin was removed but epinephrine has continued to be used. While there are some very small studies that may have shown some efficacy with vasopressin, the AHA has elected to remove it to keep the medications more streamlined. Aside from the AHA’s removal, vasopressin has been consistently on back order, comparatively expensive, and logistically more complicated. Recent research has also looked at the efficacy of Amiodarone & Lidocaine compared to a placebo. While at first glance the paper may suggest that there’s no benefit to wither medication over a placebo, some benefit may have been shown for stimulating ROSC in the OHCA.