Altered mental status predicts length of stay but not death in a community-based cohort of hospitalized COVID-19 patients.

introductionAltered Mental Status (AMS) is a common neurological complication in patients hospitalized with the diagnosis of COVID-19 (Umapathi et al., 2020; Liotta et al., 2020). Studies show that AMS is associated with death and prolonged hospital stay. In addition to respiratory insufficiency, COVID-19 causes multi-organ failure and multiple metabolic derangements, which can cause AMS, and the multi-system involvement could account for the prolonged hospital stay and increased mortality. In this study, we built on our previous publication (Chachkhiani et al., 2020) using a new, larger cohort to investigate whether we could reproduce our previous findings while addressing some of the prior study's limitations. Most notably, we sought to determine whether AMS still predicted prolonged hospital stay and increased mortality after controlling for systemic complications such as sepsis, liver failure, kidney failure, and electrolyte abnormalities.

objectivesThe primary purpose was to document the frequency of AMS in patients with COVID-19 at the time of presentation to the emergency room. Secondary aims were to determine: 1) if AMS at presentation was associated with worse outcomes as measured by prolonged hospitalization and death; and 2) if AMS remained a predictor of worse outcome after adjusting for concomitant organ failure and metabolic derangements.

resultsOut of 367 patients, 95 (26%) had AMS as a main or one of the presenting symptoms. Our sample has a higher representation of African Americans (53%) than the US average and a high frequency of comorbidities, such as obesity (average BMI 29.1), hypertension (53%), and diabetes (30%). Similar to our previous report, AMS was the most frequent neurological chief complaint. At their admission, out of 95 patients with AMS, 83 (88%) had organ failure or one of the systemic problems that could have caused AMS. However, a similar proportion (86%) of patients without AMS had one or more of these same problems. Age, race, and ethnicity were the main demographic predictors. African Americans had shorter hospital stay [HR1.3(1.0,1.7),p = 0.02] than Caucasians. Hispanics also had shorter hospital stay than non-Hispanics [HR1.6(1.2,2.1), p = 0.001]. Hypoxia, liver failure, hypernatremia, and kidney failure were also predictors of prolonged hospital stay. In the multivariate model, hypoxia, liver failure, and acute kidney injury were the remaining predictors of longer hospital stay, as well as people with AMS at baseline [HR0.7(0.6,0.9), p < 0.02] after adjusting for the demographic characteristics and clinical predictors. AMS at baseline predicted death, but not after adjusting for demographics and clinical variables in the multivariate model. Hypoxia and hyperglycemia at baseline were the strongest predictors of death.

conclusionAltered mental status is an independent predictor of prolonged hospital stay, but not death. Further studies are needed to evaluate the causes of AMS in patients with COVID-19.