With ICU beds at a premium, efforts are often made to transfer patients out of the ICU as soon as possible, but this could be particularly detrimental for older patients in whom readmission to the ICU is associated with a steep increase in mortality, according to a recent study.

Although geriatric patients comprise about one-fourth of all trauma admissions, geriatric ICU readmission has not been thoroughly studied. To get a better grasp of outcomes in this vulnerable population, Lindsey L. Perea, DO, and her colleagues conducted a retrospective study of all patients aged 40 years and older admitted to accredited Pennsylvania trauma centers between 2003 and 2018.

“We hypothesized that older patients with ICU bounce back (ICUBB) would have greater mortality rates than their younger counterparts. We also hypothesized that older age would lead to higher mortality,” said Dr. Perea, a trauma and acute care surgeon with Penn Medicine Lancaster General Health, in Lancaster, Pa., who presented the study at the 2021 Southeastern Surgical Congress.

Of all patients aged 40 years and older admitted to trauma centers during the 16-year study period, 3,896 (1.1%) met the inclusion criteria for ICUBB (i.e., being transferred to the ICU, then readmitted to the ICU during the same hospital stay). The ICUBB group was older, had a higher injury severity score and had a significantly longer hospital stay than the non-ICUBB population, at 12 and four days, respectively.

The ICUBB group also underwent intubation more frequently, and had a higher incidence of mortality, 12.6%, compared with 5% for non-ICUBB patients. The risk for mortality increased with each decade of age and was most significant in the oldest patients.

“When comparing the bounce-back and non–bounce-back groups, we found alarmingly high increased odds of mortality in our octogenarians and nonagenarians, with an odds ratio of 11.31 in the 80 to 89 group and 35 in the 90-plus group,” compared with those aged 40 to 49 years, Dr. Perea said. In contrast, the odds ratio of mortality in ICUBB patients 50 to 59 was 1.02 compared with those 40 to 49.

Of note, although ICUBB was associated with severe injuries to the head, neck, abdomen and chest, on multivariate analysis the injuries themselves were not associated with increased mortality.

“That raises the question of whether these patients were ready to leave the ICU initially,” Dr. Perea said.

She acknowledged limitations of the paper: Being limited to a single-state database, it may not be generalizable to the greater population, and the researchers were not able to discern the temporal nature of ICU admission.

“But given the profound increase in mortality in our aging trauma patients, it’s imperative to introduce initiatives to address the underlying causes of unplanned ICU readmissions to identify and mitigate risk in this vulnerable geriatric population,” Dr. Perea said.