Intraoperative administration of isoflurane improves survival in rats exposed to caecal ligation and puncture

BACKGROUND: Emerging data suggest that volatile anaesthetic agents may be protective during critical illness. METHODS: Three-month-old Sprague Dawley rats were randomly allocated to one of four groups: isoflurane during surgery followed by 3 days of isoflurane 0.8% (and intralipid i.v.), propofol during surgery and 314 μg kg(−1) h(−1) propofol for 3 days, isoflurane during surgery and intralipid for 3 days, and propofol during surgery and intralipid for 3 days. After induction with propofol or isoflurane, rats breathed oxygen 100% spontaneously via a nose cone. Propofol or intralipid was administered through a 22-gauge jugular vein i.v. catheter. Caecal ligation and puncture was performed through a paramedian incision. The surgical concentration of isoflurane was kept at 2%, and propofol was maintained at 800 μg kg(−1) h(−1). After recovery and 3 days of exposure to intralipid or anaesthetic agents, the rats were allowed to roam free in an adequately vented, temperature- and humidity-controlled cage with food and water ad libitum. RESULTS: Rats that received isoflurane for 3 days survived longer than the postoperative propofol group (P=0.0002, log-rank test). Among rats receiving no postoperative anaesthetic, those receiving isoflurane during surgery survived longer than those that received propofol during surgery group (P=0.0081). CONCLUSIONS: Exposure to isoflurane, as opposed to propofol, may improve survival in rats exposed to caecal ligation and puncture.