Secondary Logo

Institutional members access full text with Ovid®

Prevalence, Risk Factors, and Outcomes of Delirium in Mechanically Ventilated Adults*

Mehta, Sangeeta MD1; Cook, Deborah MD2; Devlin, John W. PharmD3; Skrobik, Yoanna MD4; Meade, Maureen MD5,6; Fergusson, Dean PhD7; Herridge, Margaret MD8; Steinberg, Marilyn RN9; Granton, John MD10; Ferguson, Niall MD11; Tanios, Maged MD12; Dodek, Peter MD13; Fowler, Robert MD14,15; Burns, Karen MD16,17; Jacka, Michael MD18; Olafson, Kendiss MD19; Mallick, Ranjeeta PhD7; Reynolds, Steven MD20,21; Keenan, Sean MD20,21; Burry, Lisa PharmD22

doi: 10.1097/CCM.0000000000000727
Clinical Investigations
Buy
SDC

Objective: Delirium is common during critical illness and associated with adverse outcomes. We compared characteristics and outcomes of delirious and nondelirious patients enrolled in a multicenter trial comparing protocolized sedation with protocolized sedation plus daily sedation interruption.

Design: Randomized trial.

Setting: Sixteen North American medical and surgical ICUs.

Patients: Four hundred thirty critically ill, mechanically ventilated adults.

Interventions: All patients had hourly titration of opioid and benzodiazepine infusions using a validated sedation scale. For patients in the interruption group, infusions were resumed, if indicated, at half of previous doses. Delirium screening occurred daily; positive screening was defined as an Intensive Care Delirium Screening Checklist score of 4 or more at any time.

Measurements and Main Results: Delirium was diagnosed in 226 of 420 assessed patients (53.8%). Coma was identified in 32.7% of delirious compared with 22.7% of nondelirious patients (p = 0.03). The median time to onset of delirium was 3.5 days (interquartile range, 2–7), and the median duration of delirium was 2 days (interquartile range, 1–4). Delirious patients were more likely to be male (61.1% vs 46.6%; p = 0.005), have a surgical/trauma diagnosis (21.2% vs 11.0%; p = 0.030), and history of tobacco (31.5% vs 16.2%; p = 0.002) or alcohol use (34.6% vs 20.9%; p = 0.009). Patients with positive delirium screening had longer duration of ventilation (13 vs 7 d; p < 0.001), ICU stay (12 vs 8 d; p < 0.0001), and hospital stay (24 vs 15 d; p < 0.0001). Delirious patients were more likely to be physically restrained (86.3% vs 76.7%; p = 0.014) and undergo tracheostomy (34.6% vs 15.5%; p < 0.0001). Antecedent factors independently associated with delirium onset were restraint use (hazard ratio, 1.87; 95% CI, 1.33–2.63; p = 0.0003), antipsychotic administration (hazard ratio, 1.67; 95% CI, 1.005–2.767; p = 0.047), and midazolam dose (hazard ratio, 0.998; 95% CI, 0.997–1.0; p = 0.049). There was no difference in delirium prevalence or duration between the interruption and control groups.

Conclusion: In mechanically ventilated adults, delirium was common and associated with longer duration of ventilation and hospitalization. Physical restraint was most strongly associated with delirium.

Supplemental Digital Content is available in the text.

1Department of Medicine and Interdepartmental Division of Critical Care, Mount Sinai Hospital and University of Toronto, Toronto, ON, Canada.

2Departments of Medicine, Clinical Epidemiology, and Biostatistics, McMaster University, St Joseph’s Healthcare, Hamilton, ON, Canada.

3School of Pharmacy, Northeastern University, Boston, MA.

4Département de Médecine, Soins Intensifs, Hôpital Maisonneuve Rosemont, Université de Montréal, Montréal, QC, Canada.

5Departments of Medicine, Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.

6Department of Critical Care, Hamilton Health Sciences, Hamilton, ON, Canada.

7Clinical Epidemiology Program, Ottawa Hospital Research Institute and Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.

8Department of Medicine and Interdepartmental Division of Critical Care, University Health Network and University of Toronto, Toronto, ON, Canada.

9Department of Medicine, Mount Sinai Hospital, Toronto, ON, Canada.

10Division of Respirology, Interdepartmental Division of Critical Care, Faculty of Medicine, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.

11Interdepartmental Division of Critical Care Medicine, Departments of Medicine and Physiology, University of Toronto, University Health Network and Mount Sinai Hospital, Toronto, ON, Canada.

12Department of Medicine, Long Beach Memorial Medical Center, Long Beach, CA.

13Division of Critical Care Medicine and Center for Health Evaluation and Outcome Sciences, St. Paul’s Hospital and University of British Columbia, Vancouver, BC, Canada.

14Departments of Medicine and Critical Care Medicine, Sunnybrook Hospital, Toronto, ON, Canada.

15Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada.

16Keenan Research Centre and the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, ON, Canada.

17Interdepartmental Division of Critical Care Medicine and the Institute of Health Policy Management and Evaluation, University of Toronto, Toronto, ON, Canada.

18Departments of Anesthesiology and Critical Care, University of Alberta Hospital, Edmonton, AB, Canada.

19Section of Critical Care, Department of Medicine, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada.

20Department of Medicine, Royal Columbian Hospital, New Westminster, BC, Canada.

21Department of Medicine, Surrey Memorial Hospital, Surrey, BC, Canada.

22Department of Pharmacy and Medicine, Mount Sinai Hospital and University of Toronto, Toronto, ON, Canada.

* See also p. 703.

Trial Registration: ClinicalTrials.gov Identifier NCT00675363.

Members of the SLEAP investigators are listed in the supplementary material (Supplemental Digital Content 1, http://links.lww.com/CCM/B133).

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (http://journals.lww.com/ccmjournal).

Supported, in part, by the Canadian Institutes of Health Research and the Department of Pharmacy, Mount Sinai Hospital, Toronto, ON, Canada.

Dr. Mehta received support for article research from the Canadian Institutes for Health Research (CIHR). Dr. Cook is a Canada Research Chair of the CIHR. Dr. Granton consulted for Ikaria (membership of steering committee for international study of pulmonary hypertension) and Actelion (membership of Data Safety Monitoring Committee for international clinical trial), received other support from Actelion (support of hospital foundation), received support for travel from Actelion (coverage of expenses to present as an invited speaker at an international meeting), and lectured for Actelion (regional meeting). His institution consulted for Bayer and Actelion (advisory panel retreatment of pulmonary hypertension) and received grant support from Actelion (clinical trials of macitentan, caripul, and oral prostanoid agonist in pulmonary hypertension and clinical trial of macitentan in patients with pulmonary hypertension secondary to heart disease), Bayer (clinical trial of riociguat in thromboembolic pulmonary hypertension and clinical trial of riociguat in patients with pulmonary fibrosis and pulmonary hypertension), and Ikaria (clinical trial of inhaled nitric oxide in pulmonary hypertension). Dr. Ferguson’s institution received grant support from the CIHR. Dr. Dodek’s institution received grant support (funding from the coordinating center to conduct the study at our site). Dr. Fowler is a clinician scientist of the Heart and Stroke Foundation and received support for article research from the CIHR. Dr. Olafson’s institution received grant support (grant money to pay for research nurse time for this research project). Dr. Reynolds lectured for Pfizer (development of slide deck for treatment of hospital-acquired pneumonia) and has patents with Lungpacer (medical device copatent holder). His institution received grant support from Covidien (for investigator-driven ventilator research) and Pfizer (lecturing on antibiotic use). Dr. Burry’s institution received grant support from the CIHR (academic funding). The remaining authors have disclosed that they do not have any potential conflicts of interest.

For information regarding this article, E-mail: geeta.mehta@utoronto.ca

Copyright © by 2015 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.