Cardiac arrest ICU admissions rose with outdoor heat, especially in women, older adults

As temperatures in the U.S. rose above 90°F (32°C), the rate of out-of-hospital cardiac arrest (OHCA) admissions to intensive care units (ICUs) also increased. However, the heat did not seem to affect the overall outcomes of people admitted for cardiac arrest during heat waves compared to other times, according to new preliminary research.

OHCA is a serious cardiovascular emergency with a 90% mortality rate. Vulnerable populations include older adults, those with disabilities, and individuals without air conditioning or reliable transportation. Researchers analyzed data from 10 health systems across the U.S. and found that those admitted during extreme heat (90°F or 32°C) were more likely to require interventions for low blood pressure and kidney dysfunction during their ICU stay.

Despite these additional clinical interventions, the overall discharge status and survival rate of these individuals were similar to those admitted during milder temperatures. The researchers were surprised to find that outcomes were not significantly different between the two groups, suggesting that clinicians effectively stabilized OHCA patients upon admission.

However, they emphasize that the increase in ICU admissions during heat waves puts additional strain on hospital resources, as ICU beds, equipment, and staff are limited. The study suggests that health care systems must adapt and prepare for the growing impact of extreme heat, and hospitals could potentially use temperature forecasts to adequately prepare for climate-related illnesses.