Prediction of Postoperative Pulmonary Complications in a Population-based Surgical Cohort

TLDR

Current knowledge of postoperative pulmonary complication risk is limited to narrowly selected patient and procedure studies. The study aimed to develop a predictive index for PPCs using a reduced set of perioperative variables in a broad surgical population. The authors used a prospective multicenter cohort of 2,464 patients, randomly split into development and validation sets, to build a logistic regression model identifying seven independent risk factors for PPCs. The resulting index, based on seven objective factors, achieved an AUC of 90% in development and 88% in validation, correctly identified 5% of patients with PPCs, and was associated with a markedly higher 30‑day mortality (19.5% vs 0.5%).

Abstract

Current knowledge of the risk for postoperative pulmonary complications (PPCs) rests on studies that narrowly selected patients and procedures. Hypothesizing that PPC occurrence could be predicted from a reduced set of perioperative variables, we aimed to develop a predictive index for a broad surgical population.Patients undergoing surgical procedures given general, neuraxial, or regional anesthesia in 59 hospitals were randomly selected for this prospective, multicenter study. The main outcome was the development of at least one of the following: respiratory infection, respiratory failure, bronchospasm, atelectasis, pleural effusion, pneumothorax, or aspiration pneumonitis. The cohort was randomly divided into a development subsample to construct a logistic regression model and a validation subsample. A PPC predictive index was constructed.Of 2,464 patients studied, 252 events were observed in 123 (5%). Thirty-day mortality was higher in patients with a PPC (19.5%; 95% [CI], 12.5-26.5%) than in those without a PPC (0.5%; 95% CI, 0.2-0.8%). Regression modeling identified seven independent risk factors: low preoperative arterial oxygen saturation, acute respiratory infection during the previous month, age, preoperative anemia, upper abdominal or intrathoracic surgery, surgical duration of at least 2 h, and emergency surgery. The area under the receiver operating characteristic curve was 90% (95% CI, 85-94%) for the development subsample and 88% (95% CI, 84-93%) for the validation subsample.The risk index based on seven objective, easily assessed factors has excellent discriminative ability. The index can be used to assess individual risk of PPC and focus further research on measures to improve patient care.