Independent Predictors and Outcomes of Unanticipated Early Postoperative Tracheal Intubation after Nonemergent, Noncardiac Surgery

BACKGROUND: Although the risk of hypoxemia is greatest during the first 72 h after surgery, little is known of the incidence of respiratory failure during this period. The authors studied the incidence and predictors of unanticipated early postoperative intubation (within 3 days) and its role in mortality. METHODS: A total of 222,094 adult patients undergoing nonemergent, noncardiac surgery in the American College of Surgeons-National Surgical Quality Improvement Program database were studied to determine the incidence and independent predictors of unanticipated early postoperative intubation. A risk-class model was developed and subsequently validated in 109,636 patients. RESULTS: Overall, 2,828 of 5,725 (49.4%) unanticipated tracheal intubations in a period of 30 days occurred within the first 3 days after surgery. The incidence of unanticipated early postoperative intubation was 0.83-0.9% in the derivation and validation cohorts. Independent predictors of unanticipated early postoperative intubation included current ethanol use, current smoker, dyspnea, chronic obstructive pulmonary disease, diabetes mellitus needing insulin therapy, active congestive heart failure, hypertension requiring medication, abnormal liver function, cancer, prolonged hospitalization, recent weight loss, body mass index less than 18.5 or ≥ 40 kg/m, medium-risk surgery, high-risk surgery, very-high-risk surgery, and sepsis. Unanticipated early postoperative intubation was an independent predictor of 30-day mortality, with an adjusted odds ratio of 9.2. Higher risk classes were associated with increasing incidence of unanticipated early postoperative intubation and death. CONCLUSIONS: One half of unanticipated tracheal intubations in a period of 30 days occurred within the first 3 days after nonemergent, noncardiac surgery and were independently associated with a 9-fold increase in mortality. The authors present a validated perioperative risk class index for determining risk of unanticipated early postoperative intubation.