Prolonged intubation rates after coronary artery bypass surgery and ICU risk stratification score.

OBJECTIVE: To determine prolonged intubation rates among patients undergoing coronary artery bypass graft (CABG) surgery, and to evaluate the ability of the Intensive Care Unit Risk Stratification Score (ICURSS) model to predict these events.

DESIGN: Prospective observational study.

SETTING: A 24-bed ICU in a tertiary referral university hospital.

PATIENTS: Five hundred sixty-nine patients undergoing CABG surgery.

INTERVENTIONS: Variables of the ICURSS model were recorded at ICU admission. Extubation was performed according to a standard protocol. Patients remaining intubated within 8 h after ICU admission were designated as having early extubation failure (EEF). The next evaluations at 16, 24, 48, 72, and 96 h designated patients as having a prolonged intubation period (PIP) and prolonged mechanical ventilation (PMV) for 24, 48, 72, and 96 h. The ability of the ICURSS model to predict extubation failure at different cutoff values was measured using the Hosmer-Lemeshow goodness-of-fit test and the area under the receiver operating characteristic curve.

MEASUREMENTS AND RESULTS: Prolonged intubation rates were as follows: EEF, 40.2%; PIP, 17.2%; PMV for 24 h, 10.4%; PMV for 48 h, 7.6%; PMV for 72 h, 6.5%; and PMV for 96 h, 6.0%. At every cutoff, the ICURSS showed poor discrimination to predict the failure to be extubated. Calibration was also poor, although some ability to predict both EEF and PMV at > or = 48 h was shown.

CONCLUSIONS: Prolonged intubation rates after undergoing CABG surgery in our setting were comparable with those of other reports from institutions where fast-track cardiac anesthesia is currently in practice. In our cohort, the ICURSS was not useful for the prediction of length of intubation.