Association between opioid infusion use and duration of mechanical ventilation and related outcomes in critically ill adults: a systematic review and meta-analysis

Background: We performed a systematic review with meta-analysis to examine the relationship between sedation including a continuous IV opioid infusion and duration of mechanical ventilation (MV) and relevant secondary outcomes in MV critically ill adults. Methods: We searched MEDLINE, EMBASE, and Cochrane CENTRAL database up to March 2025. We included randomized controlled trials in MV critically ill adults comparing use of sedation including a continuous IV opioid versus sedation without. We assessed MV duration, pain, delirium and coma occurrence, ICU/hospital length of stay (LOS) and 28-day mortality. Study risk of bias was evaluated (PROSPERO: CRD42024498555). We pooled data using a Restricted Maximum Likelihood Estimation random-effects model and followed PRISMA guidelines. Results: Eight studies (n = 803 patients) published between 2006 and 2021 were included. Sedation including a continuous IV opioid (vs. sedation without) may increase MV duration (3 studies, 425 patients, mean difference (MD) = 3.63 h, 95% confidence interval (CI) 2.27-4.99, very low certainty), reduce pain (2 studies, VAS score at 24 h MD = -0.44 mm, 95% CI - 0.82 to -0.07, low certainty), reduce delirium (3 studies, odds ratio (OR) = 0.28, 95% CI 0.16 to 0.47, very low certainty) and reduce mortality (3 studies, OR = 0.41, 95% CI 0.21 to 0.80, very low certainty). Sedation including a continuous IV opioid does not increase coma or reduce ICU/ hospital LOS. Risk of bias was critical for most studies. Conclusion: The effect of sedation including a continuous IV opioid on MV duration, pain delirium, coma, mortality and LOS remain uncertain. The role for continuous IV opioids as a part of ICU sedation regimens requires additional evaluation.