Cardiac arrest is common in critically ill patients with Covid-19 and is associated with poor survival, particularly among patients aged 80 or older, say researchers.

The findings, published in the journal The BMJ, could help guide end-of-life care discussions with critically ill patients with Covid-19 and their families, say the researchers.

For the study, the research team from Michigan University in the US set out to estimate the incidence, risk factors, and outcomes associated with in-hospital cardiac arrest and cardiopulmonary resuscitation (CPR) in critically ill adults with Covid-19.

Their findings are based on data for 5,019 critically ill patients (aged 18 years or over) with Covid-19 admitted to intensive care units at 68 hospitals across the United States.

The results show that 701 (14 per cent) of patients had in-hospital cardiac arrest within 14 days of admission to the intensive care unit, of whom only 400 (57 per cent) received CPR.

“Patients who had in-hospital cardiac arrest were older (average age 63 v 60 years), had more underlying health conditions (comorbidities), and were more likely to be admitted to a hospital with fewer intensive care unit beds,” the study authors wrote.

Importantly, this suggests that hospital resources, staffing, expertise, strain, or other factors not captured in this study, could have had a major impact, the researchers noted.

Patients who received CPR were younger than those who did not (average age 61 v 67 years). Among those who did receive CPR, only 12 per cent (48 out of 400) survived to hospital discharge, and the only seven per cent (28 out of 400) did so with normal or mildly impaired neurological status.

Most patients who survived to hospital discharge needed only a short course of CPR. Survival also differed by age, with 21 per cent of patients younger than 45 years surviving compared with three per cent of those aged 80 or older.

The researchers pointed to some limitations, such as being unable to assess the quality and timeliness of CPR and limiting data to the first 14 days after intensive care unit admission, potentially underestimating the true rate of cardiac arrest. However, strengths included the use of high quality, detailed data for a large number of patients who were followed until death or discharge.

However, the researchers noted that cardiac arrest is common in critically ill patients with Covid-19 and is associated with poor survival even when CPR is provided.