John is a 46 year old male with a past history of Hypertension and Hyperlipidemia. He takes his medications religiously each day at the persistence of his wife and 2 daughters who live with him. Unfortunately, John is pretty unlucky and goes into cardiac arrest in the presence of his family on Thanksgiving.
John is a cut and dry cardiac arrest. You arrive on scene rapidly, shock him and immediately obtain ROSC. The ETCO2 of 62 with your mask BVM ventilations is a welcome sight to his family and you. The firefighter in the corner, visibly impressed with the life saving he witnessed, pushes the backboard to you and says “do you want help log rolling him?” You look at your pads tracing on the monitor and note a HR of 60 and visible ST elevations. John is young, time is muscle! Should we stabilize him now or just take off and check off tasks in transit?
I want to introduce the concept of the Post Arrest Pause- 10 minutes to save a life. The main focus of this 10 minutes is ensuring appropriate preparation for defibrillation, appropriate oxygenation and maintenance or improvement of hemodynamics.
Re-arrest isn’t uncommon in the EMS environment. In a study performed in Pittsburgh, the Re-arrest (RA) rate was 38% (1). Additionally, patients who suffered from RA carried a lower survival to hospital discharge (23.1%) vs those without RA (27.8%).
In the majority of the patients noted in the study above, VF or VT were the most common rhythms noted during RA. It is common knowledge that early defibrillation improves our chances of ROSC with neurologically intact survival, but does pad placement matter?
There is limited data on pad placement and associated ROSC with patients suffering from cardiac arrest, must less re-arrest. However, a pilot RCT released in 2020 showed some interesting data for patients in refractory ventricular fibrillation. Of the patients with refractory VF, 25% in standard pad placement achieved ROSC vs 39.3% in the vector change group (2). Given that the RA rhythm was either VF or VT in 50% of patients (1), application of pads in the AP position immediately after ROSC can yield gains, especially if not feasible with on going CPR initially.
Alright, we have checked off pad placement and prepared for potential dysrhythmia, but what about the airway? We know ventilating patients and ensuring adequate oxygenation during patient movement is especially challenging. Additionally, the success rate of intubation in a moving ambulance is less than while stationary(3). Given this information, it is most likely safer to perform an RSI on scene if your patients respiratory status and ability to protect their airway dictate such. This will allow a single provider to manage ventilation and endotracheal tube management during any movements. If personal or resources are limited, an airway adjunct can allow for adequate ventilation, however will often require more dedicated personal for an adequate seal. If an endotracheal tube or SGA was placed during the arrest, this is an appropriate time to add PEEP and ensure an adequate oxygen supply for extrication to the ambulance.
The last part of our pause is the treatment of hypotension. Post cardiac arrest hypotension is seen in approximately 47% of patients. This hypotension is thought to contribute to their higher rates of mortality and poor discharge function(4). Given the frequency of post arrest hypotension, it is reasonable to prepare a vasopressor with ROSC prior to any hypotensive episodes. Norepinpherine and Epinpehrine are common first line vasoactives in post arrest patients. Given the timing of making an infusion and preparation for either gravity or infusion pump administration, it may be reasonable to prepare a push dose vasoactive to allow for rapid treatment of hypotension while you delegate the preparation of a longer term infusion.
Now that we’ve reframed our immediate action steps after ROSC for John, lets run through the flow of this pause with a checklist for reference.
ROSC is noted with a rise in ETCO2. You immediately palpate a pulse, handing the firefighter next to the patient a set of fresh defibrillation pads and instructing him to place them in the AP position. As the patient is rolled back into the supine position, he is placed on a backboard. A 12 lead is obtained.
John begins spontaneously breathing with an adequate rate and volume. His oxygen rapidly rises to 100% on the BVM and he is switched to a non rebreather for movement. You mix a syringe of 1:100,000 epinephrine in preparation for probable hypotension with plans to prepare an infusion in the ambulance. A second O2 bottle is brought to the patients side. Prior to movement you confirm an intact airway, good ventilation, a pulse with correlating BP and secured access. You now direct the fire department to lift John and place him in your ambulance for transport to a PCI center.
1. Salcido, D. D., Stephenson, A. M., Condle, J. P., Callaway, C. W., & Menegazzi, J. J. (2010, October). Incidence of rearrest after return of spontaneous circulation in out-of-hospital cardiac arrest. Prehospital emergency care : official journal of the National Association of EMS Physicians and the National Association of State EMS Directors. Retrieved February 27, 2022, from https://pubmed.ncbi.nlm.nih.gov/20809686/
2. Cheskes, S., Dorian, P., Feldman, M., McLeod, S., Scales, D. C., Pinto, R., Turner, L., Morrison, L. J., Drennan, I. R., & Verbeek, P. R. (2020, February 19). Double sequential external defibrillation for refractory ventricular fibrillation: The dose VF pilot randomized controlled trial. Resuscitation. Retrieved February 27, 2022, from https://pubmed.ncbi.nlm.nih.gov/32084567/
3. Apiratwarakul, K., Phungeon, P., Gaysornsiri, D., & Kamonwon Lenghong. (2020, June). Endotracheal intubation on a stationary vs. moving ambulance. Retrieved February 27, 2022, from https://www.researchgate.net/publication/342530210_Endotracheal_Intubation_on_a_Stationary_vs_Moving_Ambulance
4. Trzeciak S;Jones AE;Kilgannon JH;Milcarek B;Hunter K;Shapiro NI;Hollenberg SM;Dellinger P;Parrillo JE; (2009, November). Significance of arterial hypotension after resuscitation from cardiac arrest. Critical care medicine. Retrieved February 27, 2022, from https://pubmed.ncbi.nlm.nih.gov/19866506/#:~:text=Post%2DROSC%20hypotension%20is%20common,improve%20outcomes%20from%20cardiac%20arrest.'