Source: Neuroimaging Clin N Am  |  Posted 6 years ago

By Mike Fillon

ATLANTA, GA -- October 24, 2005 -- A study presented here at the American Society of Anesthesiologists (ASA) Annual Meeting shows that use of the inhaled anesthetic agent isoflurane is associated with better neurocognitive outcomes after cardiac surgery than two other anesthesia agents, sevoflurane and desflurane.

In the randomized, double blind, prospective study, researchers compared neuropsychological outcomes and S 100 beta protein levels in 42 male patients undergoing coronary artery bypass grafting surgery (CABGS) with cardiopulmonary bypass (CPB).

Researcher Fatma Saricaoglu, MD, Assistant Professor, Hacettepe University, Ankara, Turkey, presented the study findings on September 22[^]nd[].

After induction of anaesthesia, patients were divided into three groups of 14 patients each and were given one of three treatments -- isoflurane, sevoflurane, or desflurane. The total bypass times were 63.2 minutes with isoflurane, 77.7 minutes with sevoflurane, and 78.8 minutes with desflurane.

Subjects were evaluated before surgery and on both the first day and third day after surgery using the Mini Mental State Examination Test (MMSET) and the Visual Aural Digit Span Test (VADST).

Subjects' S 100 beta protein levels were measured by blood samples taken before anesthesia, before heparinization, 15 minutes into CPB, following protamine administration, within 24 hours of surgery, and postoperative on the third and sixth day.

Results show that the postoperative third and sixth day MMSET scores and third visual written subtest scores were significantly lower in the sevoflurane group than in either the isoflurane or the desflurane groups (P < .05). In addition, S 100 beta protein levels increased with the beginning of anesthesia in Group S and D.

Although S 100 beta protein levels decreased to baseline in the first postoperative day in the sevoflurane group, it was significantly higher at the third and sixth postoperative days in the desflurane group (P < .05). S 100 beta level was significantly higher only after CPB in the isoflurane group (P < .05).

Dr. Saricaoglu said the study showed that isoflurane had a clear advantage over both sevoflurane and desflurane.

"When all three agents are measured side by side, isoflurane showed a superior neuropsychological outcome after cardiac surgery," Dr. Saricaoglu concluded.

[Presentation title: The Effects of Isoflurane, Sevoflurane, and Desflurane Anesthesia on Neurologic Outcome after Cardiac Surgery. Abstract A31]