Survival after long-term isoflurane sedation as opposed to intravenous sedation in critically ill surgical patients: Retrospective analysis.

Bellgardt, Martin; Bomberg, Hagen; Herzog-Niescery, Jenny; Dasch, Burkhard; Vogelsang, Heike; Weber, Thomas P; Steinfort, Claudia; Uhl, Waldemar; Wagenpfeil, Stefan; Volk, Thomas; Meiser, Andreas

BACKGROUND Isoflurane has shown better control of intensive care sedation than propofol or midazolam and seems to be a useful alternative. However, its effect on survival remains unclear. OBJECTIVE The objective of this study is to compare mortality after sedation with either isoflurane or propofol/midazolam. DESIGN A retrospective analysis of data in a hospital database for a cohort of consecutive patients. SETTING Sixteen-bed interdisciplinary surgical ICU of a German university hospital. PATIENTS Consecutive cohort of 369 critically ill surgical patients defined within the database of the hospital information system. All patients were continuously ventilated and sedated for more than 96 h between 1 January 2005 and 31 December 2010. After excluding 169 patients (93 >79 years old, 10 <40 years old, 46 mixed sedation, 20 lost to follow-up), 200 patients were studied, 72 after isoflurane and 128 after propofol/midazolam. INTERVENTIONS Sedation with isoflurane using the AnaConDa system compared with intravenous sedation with propofol or midazolam. MAIN OUTCOME MEASURES Hospital mortality (primary) and 365-day mortality (secondary) were compared with the Kaplan-Meier analysis and a log-rank test. Adjusted odds ratios (ORs) [with 95% confidence interval (95% CI)] were calculated by logistic regression analyses to determine the risk of death after isoflurane sedation. RESULTS After sedation with isoflurane, the in-hospital mortality and 365-day mortality were significantly lower than after propofol/midazolam sedation: 40 versus 63% (P = 0.005) and 50 versus 70% (P = 0.013), respectively. After adjustment for potential confounders (coronary heart disease, chronic obstructive pulmonary disease, acute renal failure, creatinine, age and Simplified Acute Physiology Score II), patients after isoflurane were at a lower risk of death during their hospital stay (OR 0.35; 95% CI 0.18 to 0.68, P = 0.002) and within the first 365 days (OR 0.41; 95% CI 0.21 to 0.81, P = 0.010). CONCLUSION Compared with propofol/midazolam sedation, long-term sedation with isoflurane seems to be well tolerated in this group of critically ill patients after surgery.