Elizabeth Rohrs, PhD(c)
Respiratory Therapist
Simon Fraser University, United States
Disclosure information not submitted.
Steve Reynolds, MD
Critical Care physician
Simon Fraser University, United States
Disclosure information not submitted.
Title: Meta-Analysis of Delirium and Prolonged Mechanical Ventilation
Introduction: While mechanical ventilation (MV) is a crucial life-support tool, it may also cause injury to the brain, and is a risk factor for delirium. Many studies have demonstrated greater length of hospital stay, duration of MV, and mortality in patients with delirium during hospitalization. We sought to explore the current knowledge in the literature regarding prolonged MV and delirium through a systematic review.
Methods: Following the PRISMA protocol, a librarian performed a search in publication databases including Medline, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, and the Database of Abstracts of Reviews and Effects. Only articles that were focused on links between MV and delirium were included. Papers were limited to prospective and retrospective studies published in English. Publications were separated into two subgroups: papers that reported prolonged MV as an independent variable associated with the likelihood of delirium, and papers that reported delirium as an independent variable associated with the likelihood of prolonged MV ( >8 days on MV). Odds ratios (OR) were used to calculate the weight and heterogeneity of the data in the manuscripts, using inverse covariance with a random-effects model. P-value < 0.1 for the chi-square test was considered significant. Heterogeneity was evaluated using Higgins’s metric. All statistical analyses were performed using Review Manager software (RevMan, Version 5.4.1, The Cochrane Collaboration, 2020).
Results: Our search identified 2,607 papers. After applying the inclusion criteria, 26 papers were selected to be part of our analysis. Ten papers identified prolonged duration of MV as an independent variable associated with a greater likelihood of patients developing delirium during hospitalization, reporting odds ratios ranging from 2.23 to 10.50, with a pooled odds ratio of 3.42 (Figure 1). Seven papers identified delirium during hospitalization as an independent variable associated with a greater likelihood of prolonged duration of MV, reporting odds ratios ranging from 1.15 to 10.14, with a pooled odds ratio of 2.06 (Figure 2).
Conclusion: The literature suggests an association between prolonged MV and delirium.