Understanding the Enemy: In-Hospital Cardiac Arrest in COVID19

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The Pre-brief

The COVID-19 pandemic has challenged the medical community this last year, as few others have. One of the staggering statistics that continue to embattle our healthcare system is the fatality rate of in-hospital cardiac arrest in COVID patients. While the topic of cardiac arrest management, the pathophysiology of COVID arrest, and ethics are all important topics, today I want to concentrate on a British Medical Journal article out from the STOP-COVID investigators at University of Michigan and Harvard University entitled, In-hospital cardiac arrest in critically ill patients with covid-19: a multicenter cohort study. This is a multi-center cohort study that looked at the incidence, risk factors, and outcomes associated with in-hospital cardiac arrest and cardiopulmonary resuscitation in critically ill adults with coronavirus disease in 2019.

The study obtained data from 68 hospitals across the US and enrolled  5,019 patients. Participants enrolled were 18 or older with confirmed COVID-19, with the primary measure looking at cardiac arrest within 14 days of admission to an intensive care unit and in-hospital mortality.

The numbers were staggering. Of the 5019 patients admitted with COVID 19, 701 (14%) sustained an in-hospital cardiac arrest. Of those 701 patients, 400 (57.1%) received cardiopulmonary resuscitation. 135 of the 400 patients (33.8%) who received cardiopulmonary resuscitation achieved return of spontaneous circulation. 48 (12%) patients survived to discharge, but only 28 (7%)) were discharged with average or mild neurological impairment. 

The mean age of patients who had an in-hospital cardiac arrest was 63 and typically had more comorbidities and were often admitted to smaller hospitals with fewer ICU beds. The mean age of patients that received resuscitative efforts was 61. Survival to discharge differed dramatically, with 21.2% of patients younger than 45 years survived compared to 2.9% (1/34) of those aged 80 or older. 

The most common initial rhythm was pulseless electrical activity (49.9%,199/400) and asystole (23.8%, 95/400). 

In the patients that did receive resuscitative efforts, Epinephrine was the most commonly used treatment during cardiopulmonary resuscitation (81.0%, 324/400), followed by defibrillation (18.5%, 74/400). The median duration of cardiopulmonary resuscitation was 10 minutes (interquartile range 5-18). Younger patients received cardiopulmonary resuscitation for a longer duration than older patients (median 13 minutes (interquartile range 7-20) in patients younger than 45 years compared with 7 minutes (4-14) in patients aged 80 or older).

The authors of the article identified three important implications from their findings. 

  1. A large percentage of critically ill patients that were admitted to the hospital would suffer a cardiac arrest.
  2. The data set was able to help identify important patient and hospital risk factors, thereby highlighting patients that may need closer monitoring or earlier goals of treatment discussions
  3. Information on survival could guide end of life care discussions with critically ill patients and their families as the data helped characterize the likelihood of survival in critically ill COVID-19 patients.

Strengths of their study:

  1. Large study with 5019 patients
  2. Data were obtained from chart review at 68 hospitals
  3. All patients were followed until death, hospital discharge, or a minimum of 30 days from admission to the intensive care unit. 
  4. Collection of neurologic status at hospital discharge among survivors.


  1. Data on the cardiac rhythm of patients who did not receive resuscitation were not available
  2. Unable to obtain data from the timing of initial treatment such as chest compressions or defibrillation. This made assessing the quality and timeliness of resuscitation, which could have been compromised from personnel donning PPE, could have contributed to poor outcomes.
  3. The data was collected on patients admitted between 4 March and 1 June 2020, which might not reflect current trends.
  4. The true cardiac arrest numbers may have been underestimated as patients were only followed for 14 days after admission to the intensive care unit.

The Debrief

So what does this multicenter cohort study tell me? COVID patients that were younger with fewer comorbidities and were admitted to larger institutions were more likely to survive their critical illness of COVID19. Science struggled to improve cardiac arrest outcomes before this pandemic, but COVID19 has proven to be a challenge that has overwhelmed our systems. The elevated rates of cardiac arrest in COVID patients and the unique pathophysiology that may contribute to it are still being assessed. The authors reference that cardiac arrest in critically ill patients with COVID19 appeared to be predominantly related to non-cardiac causes. The initial rhythm for most patients in their study was non-shockable (pulseless electrical activity or asystole in 73% of patients). Respiratory failure and prothrombotic events that have been extensively described in patients with covid-19 are probably significant contributors to in-hospital cardiac arrest in this setting.

With this data, I believe we can best generate a better understanding of the patient’s factors that can help guide the goals of care when discussing the futility of cardiopulmonary resuscitation in some patients. None of us like to bow to defeat when it comes to doing all we can to resuscitate our patients. Still, with limiting resources and data showing possible futility in resuscitative efforts, we may be forced to concede. Fortunately, we have seen some modalities since this study was concluded that have improved critical illness in some COVID-19 patients, such as dexamethasone. Hopefully, we can find a silver lining in this pandemic and learn to improve our systems and mitigate the factors that continue to challenge our healthcare system during this awful pandemic.


  1. Hayek SS, Brenner SK, Azam TU, Shadid HR, Anderson E, Berlin H, Pan M, Meloche C, Feroz R, O’Hayer P, Kaakati R, Bitar A, Padalia K, Perry D, Blakely P, Gupta S, Shaefi S, Srivastava A, Charytan DM, Bansal A, Mallappallil M, Melamed ML, Shehata AM, Sunderram J, Mathews KS, Sutherland AK, Nallamothu BK, Leaf DE; STOP-COVID Investigators. In-hospital cardiac arrest in critically ill patients with covid-19: multicenter cohort study. BMJ. 2020 Sep 30;371:m3513. doi: 10.1136/bmj.m3513. PMID: 32998872; PMCID: PMC7525342.


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