Predictive risk index and prognosis of postoperative reintubation after planned extubation during general anesthesia: a single-center retrospective case-controlled study in Taiwan from 2005 to 2009

Abstract

Objectives: Postoperative reintubation after planned extubation (RAP) following general anesthesia is a major anesthetic morbidity. A previous study on RAP identified the various risk factors for RAP, including chronic obstructive pulmonary disease (COPD), pneumonia, systemic inflammatory response syndrome (SIRS), and airway surgery. However, the prognosis and predictive risk index of RAP were not investigated.

Methods: Data on surgical patients who were reintubated after planned extubation at the end of surgery between January 1, 2005 and December 31, 2009 were retrospectively sorted out from the quality assurance database of the Department of Anesthesiology, Chang Gung Memorial Hospital. Risk factors and prognosis of RAP cases were compared with the control group (successful planned extubation) using descriptive statistics and logistic regression. The RAP predictive risk index was developed from multivariate logistic regression and the predictive accuracy was evaluated by goodness-of-fit test.

Results: Of the 227,876 patients who were subjected to endotracheal intubation for general anesthesia, 130 (0.06%) sustained postoperative RAP. The control group consisted of 390 patients who were randomly selected from those who underwent endotracheal intubation without RAP. A total of 30 variables, including demographic, operative, anesthetic data, and prognosis were analyzed. We found that significant risk factors for RAP included COPD (odds ratio: 4.30), pneumonia (odds ratio: 6.60), ascites (odds ratio: 4.86), SIRS (odds ratio: 7.52), hypothermia (body temperature <35°C; odds ratio: 2.45), rocuronium as muscle relaxant (odds ratio: 1.90), inexperienced anesthetic service (odds ratio: 3.44), and airway surgery (odds ratio: 4.34). An RAP predictive risk index was developed and the predictive accuracy was confirmed by goodness-of-fit test as excellent discrimination (c statistic: 0.873). RAP significantly increased postoperative stay in hospital (odds ratio: 2.46) and intensive care unit, as well as tracheostomy and mortality (odds ratio: 58.52).

Conclusion: The RAP predictive risk index included higher American Society of Anesthesiologists classification, conscious disturbance, COPD, pneumonia, SIRS, room air SpO2 <95%, hypothermia, airway surgery, and head and neck surgeries. The RAP predictive risk index provides us an opportunity to take preventive measures including renewal of risk-reduction protocols for high-risk patients.