- The more packed a hospital intensive care unit is with COVID-19 patients, the greater likelihood those patients will die, according to a new study by researchers from the Department of Veterans Affairs, Indiana University School of Medicine and a variety of other academic medical centers and research institutes.
- The researchers monitored VA medical centers with 10 or more COVID-19 patients in its ICUs between March and November of last year. Their findings of the outcomes of more than 8,500 patients were published in JAMA Network Open on Tuesday.
- The mortality rate of patients was twice as high in April — the peak of ICU demand — versus July, when about one-seventh the number of COVID-19 patients needed intensive care.
COVID-19 initially overwhelmed hospitals when it all but shut down the United States in early spring. According to this new study, that is also when mortality rates peaked for COVID-19 patients in the ICU, hitting 22.5% in March and then rising again to 25% in April.
But as the infection curve was bent later in the spring and summer and hospital capacity freed up, mortality rates declined significantly. They dropped to 15.5% in May, 13.6% in June and 12.5% in July before rising slightly to 12.8% in August. The number of COVID-19 patients in the ICUs of the hospitals had begun outstripping capacity in early April before dropping dramatically in May,
"This important early investigation suggests that mortality for patients with COVID-19 who are critically ill may be associated with the extent of burden of other patients with COVID-19 in the ICU," wrote Lewis Rubinson, chief medical officer of New Jersey's Morristown Medical Center in an accompanying commentary. "Additionally, the timing of an individual's hospitalization within the surge of the virus across the community may be associated with ICU survival, again as a result of the concurrent critical care COVID-19 burden during the individual's admission."
That likely means COVID-19 mortality rates are rising again as hospitals in Southern California and other parts of the country have reached capacity. In New York state, hospitals were ordered last month to expand capacity as part of a special surge and flex program. In the VA hospital system, ICU capacity is pegged to staffing availability. Many hospitals are currently experiencing shortages of nurses and other clinicians, prompting them to be more flexible regarding staffing.
The study does have some limitations. For example, the percentage of COVID-19 patients in ICUs above the age of 85 was significantly higher in April (14.3%) than in July (9.6%). And the proportion of Black patients, who have been hit particularly hard by COVID-19, also was significantly higher in April (51.6%) versus July (37.4%).
Moreover, since VA hospitals were being studied, the vast majority of patients (well over 90%) were men. The proportion of patients on ventilators also dropped, from 16.4% in April to 9.9% in July. Although the study has numerous controls it does not take into account new treatments and care protocols developed during the pandemic.
However, the study did conclude that patients were 1.94 times as likely to die if they were in an ICU brimming with COVID-19 patients than one that had fewer such cases. Its authors suggested hospitals within a single system or a specific geography collaborate to triage patients to facilities that had greater ICU capacity in order to reduce the mortality rate.