Newly Published
Perioperative Medicine  |   May 2017
A Systematic Review and Meta-analysis Examining the Impact of Incident Postoperative Delirium on Mortality
Author Notes
  • Department of Anesthesiology and Pain Medicine (G.M.H., M.M.L., D.I.M.), Faculty of Medicine (K.W., J.D.), Regenerative Medicine Program (M.M.L.), Clinical Epidemiology Program (D.I.M.), and The Ottawa Hospital Research Institute (M.M.L., D.I.M.), University of Ottawa, Ottawa, Ontario, Canada.
  • Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).
    Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).×
  • Submitted for publication October 4, 2016. Accepted for publication March 21, 2017.
    Submitted for publication October 4, 2016. Accepted for publication March 21, 2017.×
  • Acknowledgments: The authors acknowledge the assistance of Sascha Davis, Information Specialist (Learning Services, The Ottawa Hospital, Ottawa, Ontario, Canada), for her assistance in developing and executing our search.
    Acknowledgments: The authors acknowledge the assistance of Sascha Davis, Information Specialist (Learning Services, The Ottawa Hospital, Ottawa, Ontario, Canada), for her assistance in developing and executing our search.×
  • Research Support: Support was provided solely from institutional and/or departmental sources.
    Research Support: Support was provided solely from institutional and/or departmental sources.×
  • Competing Interests: Dr. McIsaac acknowledges salary support and use of DistillerSR from The Ottawa Hospital Department of Anesthesiology. Dr. Hamilton is a Canadian Frailty Network Highly Qualified Person. The authors declare no competing interests.
    Competing Interests: Dr. McIsaac acknowledges salary support and use of DistillerSR from The Ottawa Hospital Department of Anesthesiology. Dr. Hamilton is a Canadian Frailty Network Highly Qualified Person. The authors declare no competing interests.×
  • Correspondence: Address correspondence to Dr. McIsaac: Department of Anesthesiology, 1053 Carling Ave, Ottawa, Ontario K1Y 4E9, Canada. dmcisaac@toh.ca. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Perioperative Medicine / Central and Peripheral Nervous Systems
Perioperative Medicine   |   May 2017
A Systematic Review and Meta-analysis Examining the Impact of Incident Postoperative Delirium on Mortality
Anesthesiology Newly Published on May 4, 2017. doi:10.1097/ALN.0000000000001660
Anesthesiology Newly Published on May 4, 2017. doi:10.1097/ALN.0000000000001660
Abstract

Background: Delirium is an acute and reversible geriatric syndrome that represents a decompensation of cerebral function. Delirium is associated with adverse postoperative outcomes, but controversy exists regarding whether delirium is an independent predictor of mortality. Thus, we assessed the association between incident postoperative delirium and mortality in adult noncardiac surgery patients.

Methods: A systematic search was conducted using Cochrane, MEDLINE/PubMed, Cumulative Index to Nursing and Allied Health Literature, and Embase. Screening and data extraction were conducted by two independent reviewers. Pooled-effect estimates calculated with a random-effects model were expressed as odds ratios with 95% CIs. Risk of bias was assessed using the Cochrane Risk of Bias Tool for Non-Randomized Studies.

Results: A total of 34 of 4,968 screened citations met inclusion criteria. Risk of bias ranged from moderate to critical. Pooled analysis of unadjusted event rates (5,545 patients) suggested that delirium was associated with a four-fold increase in the odds of death (odds ratio = 4.12 [95% CI, 3.29 to 5.17]; I2 = 24.9%). A formal pooled analysis of adjusted outcomes was not possible due to heterogeneity of effect measures reported. However, in studies that controlled for prespecified confounders, none found a statistically significant association between incident postoperative delirium and mortality (two studies in hip fractures; n = 729) after an average follow-up of 21 months. Overall, as study risk of bias decreased, the association between delirium and mortality decreased.

Conclusions: Few high-quality studies are available to estimate the impact of incident postoperative delirium on mortality. Studies that controlled for prespecified confounders did not demonstrate significant independent associations of delirium with mortality.