Related Experiment Video
Updated: Aug 22, 2025

An Experimental Paradigm for the Prediction of Post-Operative Pain PPOP
Published on: January 27, 2010
Prediction of postoperative respiratory depression and respiratory complications in patients on preoperative
Ryu Komatsu1,2, Michael G Nash3, Jiang Wu4
1Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA. komatsr@ccf.org.
Purpose:
We developed prediction models for postoperative respiratory depression and respiratory complications for 958 patients who were on methadone preoperatively.
Methods:
The primary outcome was postoperative respiratory depression as defined by respiratory rate < 10/min, oxygen saturation (SpO2) < 90%, or requirement of naloxone for 48 h postoperatively. Secondary outcome was the composite of postoperative respiratory complications. Prediction models for postoperative respiratory depression and respiratory complications were constructed using multivariate logistic regression with preoperative and intraoperative characteristics as the predictors.
Results:
For the multivariate logistic regression model for postoperative respiratory depression, surgery duration (P = 0.005), body mass index (BMI) (P = 0.008), surgery involving digestive system (P = 0.031), and American Society of Anesthesiologists (ASA) physical status ≥ 4 (P = 0.038) were statistically significant predictors. The area under the receiver operating characteristic curve (AUROC) of the model was 0.581 (0.558-0.601) [median (95% confidence interval (CI))] with fivefold cross-validation. For the model for postoperative respiratory complications, surgery duration (P = 0.001), history of hypertension (P = 0.028), surgery involving musculoskeletal system (P < 0.001), surgery involving integumental system (P = 0.034), surgery categorized to miscellaneous therapeutic procedures (P = 0.028), combined general and regional anesthesia (P = 0.033), ASA physical status 3 (P < 0.001), and ASA physical status ≥ 4 (P < 0.001) were statistically significant predictors, and AUROC of the model was 0.726 (0.712-0.737).
Conclusions:
Multivariate logistic regression models including preoperative, and intraoperative characteristics as the predictors performed poorly to predict postoperative respiratory depression, and moderately for postoperative respiratory complications. Neither model is accurate enough to be subject to clinical use.
Related Concept Videos
Cardiomyopathy VII: Pre and Post Operative Nursing Management
Parenteral Anesthetics: Overview
Upper Respiratory Drugs: Antitussives, Expectorants, and Mucolytics
Antitussives include codeine, dextromethorphan (Robitussin), and benzonatate (Tessalon). Codeine and dextromethorphan exert their effects centrally by suppressing the cough reflex center in the medulla. Benzonatate operates peripherally within the respiratory tract by...
Respiratory Assessment: Purpose and Indications
Objectives and Importance:
The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a...
Stages of General Anesthesia
Opioid Analgesics: Synthetic and Semisynthetic Opioids

