Preoperative cerebral oxygen saturation is associated with time to extubation during fast-track cardiac anaesthesia

Introduction: Fast-track cardiac anaesthesia programmes have been linked to a decrease in intensive care unit and hospital lengths of stay and a decrease in mortality and morbidity [1]. It is not known which patients are ideal candidates to undergo early postoperative extubation. The present pilot study was designed to determine preand intraoperative factors influencing postoperative ventilation times in a heterogeneous cohort of cardiac surgical patients. Method: Following implementation of a new fast-track protocol at our institution, accompanied by recording preand intraoperative factors potentially influencing postoperative time on the respirator, we retrospectively analysed 79 consecutive patients. Successful fast-track was defined as time to extubation within 75 min after admission to ICU [1]. Intraoperatively, depth of anaesthesia had been titrated to achieve a bispectral-index (BIS) of 40 to 50. Results: Sixty patients fulfilled the criterion of successful fast-track (mean 43.9 min (95% CI, 40 to 47 min). 19 patients needed more than 75 min to be weaned from the respirator (135 min (95% CI, 120 to 157 min)). Analysis of preand intraoperative factors revealed that these groups differed only with respect to preoperative cerebral oxygen saturation (ScO2) levels (ScO2: short ventilation time group: 67.7 ± 5.2%; long ventilation time group: 60.8 ± 7.4%; P=0.001). The correlation between preoperative ScO2 and time to extubation was: –0.55 (95% CI, -0.68 to –0.37; P<0.0001) Receiver-Operating-Curve analysis of preoperative ScO2 readings and time to extubation revealed an AUC of 0.83 (95% CI, 0.79 to 0.91; P<0.0001). The best cutoff value to discriminate fast (≤ 75 min) versus not-so-fast (>75 min) extubation was a ScO2 ≥ 66% (sensitivity 94.7%, specificity 63.3%). Conclusions: Taking into account the limitations of the small sample size and the retrospective design, the results of this pilot study suggests that preoperative ScO2 is related to time to extubation following cardiac surgery and can thus be used to select ideal candidates for fast-track cardiac anaesthesia programmes. References: 1. Ender J, Borger MA, Scholtz M et al. Cardiac surgery Fast-track treatment in a postanesthetic care unit: six months results of a fast-track concept. Anesthesiology 2008; 109 (1): 61-6 Free oral sessions