biostudies-literatureWu JRTaipei Medical University2https://www.ebi.ac.uk/biostudies/studies/S-EPMC12764038biostudies-literatureUnknown26(1)<h4>Background</h4>Opioid-related oversedation is associated with respiratory depression and can lead to potentially catastrophic adverse events in hospitalized patients. This study aimed to investigate influential factors for postoperative sedation during morphine-based intravenous patient-controlled analgesia (IV-PCA).<h4>Methods</h4>We enrolled patients who received morphine-based IV-PCA for postoperative pain at a medical hospital between January 2020 and November 2022. The primary outcome was unintentional sedation within 72 h after surgery. The Observer Assessment of Alertness/Sedation Scale (OAA/S) was used to assess the sedation depth at 12-hour intervals. Multivariable logistic regression models were used to calculate the adjusted odds ratio (aOR) with 95% confidence interval (CI)BMC anesthesiologyRisk factors for morphine-associated sedation in intravenous patient-controlled analgesia for postoperative pain.PMC12764038TMU110-AE1-B11Wu JRChen JTWu HLWu YMCata JPCherng YGTai YHfalseRisk factors for morphine-associated sedation in intravenous patient-controlled analgesia for postoperative pain.<h4>Background</h4>Opioid-related oversedation is associated with respiratory depression and can lead to potentially catastrophic adverse events in hospitalized patients. This study aimed to investigate influential factors for postoperative sedation during morphine-based intravenous patient-controlled analgesia (IV-PCA).<h4>Methods</h4>We enrolled patients who received morphine-based IV-PCA for postoperative pain at a medical hospital between January 2020 and November 2022. The primary outcome was unintentional sedation within 72 h after surgery. The Observer Assessment of Alertness/Sedation Scale (OAA/S) was used to assess the sedation depth at 12-hour intervals. Multivariable logistic regression models were used to calculate the adjusted odds ratio (aOR) with 95% confidence interval (CI)2025-01-01T00:00:00Z2025 Nov2026-06-06T10:32:19.425Z2026-05-29T03:11:53.579ZS-EPMC127640384128675710.1186/s12871-025-03520-1