ICU delirium burden predicts functional neurologic outcomes.

Luis Paixao,Lauren M Mcclain,Eyal Y Kimchi,David W Zhou,Anudeepthi Neelagiri,Jacob Hogan,Oluwaseun Akeju,Haoqi Sun,Patrick L Purdon,M Brandon Westover,Mike Westmeijer,Katie Hartnack,Aleksandar R Zivkovic

doi:10.1371/journal.pone.0259840

Abstract

BackgroundWe investigated the effect of delirium burden in mechanically ventilated patients, beginning in the ICU and continuing throughout hospitalization, on functional neurologic outcomes up to 2.5 years following critical illness.MethodsProspective cohort study of enrolling 178 consecutive mechanically ventilated adult medical and surgical ICU patients between October 2013 and May 2016. Altogether, patients were assessed daily for delirium 2941days using the Confusion Assessment Method for the ICU (CAM-ICU). Hospitalization delirium burden (DB) was quantified as number of hospital days with delirium divided by total days at risk. Survival status up to 2.5 years and neurologic outcomes using the Glasgow Outcome Scale were recorded at discharge 3, 6, and 12 months post-discharge.ResultsOf 178 patients, 19 (10.7%) were excluded from outcome analyses due to persistent coma. Among the remaining 159, 123 (77.4%) experienced delirium. DB was independently associated with >4-fold increased mortality at 2.5 years following ICU admission (adjusted hazard ratio [aHR], 4.77; 95% CI, 2.10–10.83; P < .001), and worse neurologic outcome at discharge (adjusted odds ratio [aOR], 0.02; 0.01–0.09; P < .001), 3 (aOR, 0.11; 0.04–0.31; P < .001), 6 (aOR, 0.10; 0.04–0.29; P < .001), and 12 months (aOR, 0.19; 0.07–0.52; P = .001). DB in the ICU alone was not associated with mortality (HR, 1.79; 0.93–3.44; P = .082) and predicted neurologic outcome less strongly than entire hospital stay DB. Similarly, the number of delirium days in the ICU and for whole hospitalization were not associated with mortality (HR, 1.00; 0.93–1.08; P = .917 and HR, 0.98; 0.94–1.03, P = .535) nor with neurological outcomes, except for the association between ICU delirium days and neurological outcome at discharge (OR, 0.90; 0.81–0.99, P = .038).ConclusionsDelirium burden throughout hospitalization independently predicts long term neurologic outcomes and death up to 2.5 years after critical illness, and is more predictive than delirium burden in the ICU alone and number of delirium days.

Highlights

Delirium, a condition of an acute and fluctuating change in mental status, impaired attention, and disorganized thinking, occurs in 30–60% of patients admitted to an intensive care unit (ICU) [1, 2]
delirium burden (DB) was independently associated with >4-fold increased mortality at 2.5 years following ICU admission, and worse neurologic outcome at discharge, 3, 6, and 12 months
DB in the ICU alone was not associated with mortality (HR, 1.79; 0.93–3.44; P = .082) and predicted neurologic outcome less strongly than entire hospital stay DB

Summary

Introduction

A condition of an acute and fluctuating change in mental status, impaired attention, and disorganized thinking, occurs in 30–60% of patients admitted to an intensive care unit (ICU) [1, 2]. Few studies have tracked the course of ICU delirium throughout the entire hospital stay, little is known about the impact of the overall burden of delirium. In this prospective observational cohort study, we aimed to determine the independent impact of the burden of delirium throughout hospitalization on long-term functional neurological outcome among mechanically ventilated ICU patients. DB is not confounded by survival status nor length of hospital stay and may be a strong independent predictor of mortality and functional neurological outcomes at discharge and long-term. We investigated the effect of delirium burden in mechanically ventilated patients, beginning in the ICU and continuing throughout hospitalization, on functional neurologic outcomes up to 2.5 years following critical illness

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