[High dose epidural fentanyl suppresses the increase in cortisol levels during open chest surgery]

We investigated the effect of high dose epidural fentanyl (HEF) on plasma levels of epinephrine (E), norepinephrine (NE) and cortisol (C) during open chest surgery (OCS). Twenty five patients undergoing open chest surgery was divided randomly into two groups. Thirteen patients had HEF (F-Group) and the rest of 12 patients had epidural mepivacaine (M-Group). Epidural puncture (Th5-6) and catheterization were performed before anesthetic induction. Anesthesia was induced with thiamylal (5 mg.kg-1) and trachea was intubated after injection of vecuronium (0.1 mg.kg-1). Anesthesia was maintained with 50% N2O and isoflurane as needed. After 0.2 ml.kg-1 of fentanyl was injected through the epidural catheter, fentanyl was infused continuously (0.05 mg.h-1) in F-Group. In M-Group, after 0.2 ml.kg-1 of 1% mepivacaine was injected through the epidural catheter, 1% mepivacaine was infused continuously (10 ml.h-1). For the measurement of E, NE and C, blood samples were collected at following points; 1) before anesthetic induction, 2) before incision, 3) during open chest and 4) in the recovery room. In both groups, E and NE levels did not change significantly. In F-Group, plasma C levels decreased significantly when chest was opened. C levels in F-Group, were significantly lower than in M-Group before incision and during open chest.