Impact of a Premorbid Psychiatric Disorder on the Incidence of Delirium during ICU Stay, Morbidity, and Long-Term Mortality

Abstract

Introduction. Delirium during ICU stay is a widespread problem with complex aetiology. A premorbid psychiatric disorder has been associated with an increased incidence of delirium in the general hospital population, but data on the impact of ICU delirium and consequences for morbidity and long-term mortality remain scarce. Methods. In this single-centre retrospective analysis, 472 patients with an ICU stay >48 hours were included during a 2-year period. Postresuscitation and neurosurgical patients were not included. The primary aim of the study was to establish the incidence and duration of delirium during ICU stay in patients with (PS group) and without (NPS group) a premorbid psychiatric disorder. Data were analysed with applicable nonparametric tests. In a secondary analysis, patients were compared according to the presence or absence of delirium. Finally, a binary logistic regression model was constructed to correct for potential confounders. Results. Of all patients, 19.7% were included in the PS group. Baseline characteristics with respect to severity of illness and type of admission did not differ between groups, but PS patients were significantly younger and more often female in comparison with NPS patients. The overall incidence of delirium during ICU was 57% and did not significantly differ between groups (65% in PS group vs. 56% in the NPS group, p=0.13). In a univariate analysis, the presence of a psychiatric history was also associated with prolonged mechanical ventilation, length of stay ICU, and hospital stay, but not with long-term all-cause mortality. The presence of delirium at any time during ICU admission was significantly associated with prolonged mechanical ventilation and prolonged ICU and hospital stay, but not with mortality. In a Kaplan–Meier analysis, 5-year all-cause mortality was clearly separated between groups, but the difference remained statistically insignificant (X2=3.01, p=0.08). In a binary logistic regression model, age, male sex, APACHE III score, and premorbid psychiatric disorder (OR 1.8, CI 1.1–3.0; p=0.023) were all independently associated with the presence of delirium. Conclusions. In ICU patients with a length of stay >48 hours and a premorbid psychiatric disorder, the incidence of delirium was not significantly higher in comparison with patients without a premorbid psychiatric disorder.

The Epidemiology and Outcomes of Mental Disorders in Critically Ill Patients With Systemic Lupus Erythematosus: A Population-Based Study

“…On the other hand, in another study of veterans by the same group, involving critically ill medical patients, crude hospital mortality was lower among those with mental disorders (7.3% vs. 8.7%, respectively), but higher on adjusted analysis (OR: 1.07; 95% CI: 1.01 - 1.14), though similar at 30-day (OR: 1.01; 95% CI: 0.94 - 1.08) [ 33 ]. Finally, in a single-center study from the Netherlands, unadjusted hospital morality was lower among critically ill patients with mental disorders that those without this diagnosis (9.7% vs. 13.3%, respectively), but the difference was not statistically significant, likely due to the small cohort size [ 16 ].…”

“…These findings prompted the investigators to hypothesize that mental disorders may predispose patients to critical illness [ 14 ]. Mental disorders were reported in 6.2% [ 14 ] to 36.4% [ 15 ] of ICU patients in the general population and studies on the association between mental disorders and short-term mortality showed either no difference [ 16 ] or increased risk of death [ 17 ], as compared to those without mental disorders.…”

The effects of interactive E-learning on delirium recognition ability and delirium-related strain of care among critical care nurses

“…Delirium refers to altered consciousness and cognition with an acute onset and a fluctuating course. 1 Its prevalence in intensive care units (ICU) varies from 4% to 89%. 2,3 Delirium is specifically prevalent among patients under mechanical ventilation so that more than 80% of these patients experience delirium.…”

“…2,3 Delirium is specifically prevalent among patients under mechanical ventilation so that more than 80% of these patients experience delirium. 1,4,5 A study reported that delirium increased the length of hospital stay by 3.45 so that the length of hospital stay among patients with and without delirium was eleven and seven days, respectively. Moreover, delirium increased the risk of death by 2.43 times.…”

Baseline Anxiety and Depression and Risk for ICU Delirium: A Prospective Cohort Study

“…Studies evaluating the association between mental disorders before ICU admission and ICU delirium occurrence have reported conflicting results and have important limitations (8)(9)(10)(11). Study populations have been small, the presence of anxiety and/or depression has not been rigorously evaluated, trained evaluators have not conducted delirium assessments, and the presence of established baseline and ICU daily factors for delirium has not been rigorously considered.…”