[Remifentanil for intraoperative anesthesia].

OBJECTIVE: To compare the efficacy and safety of remifentanil with fentanyl used for intraoperative anesthesia. METHODS: Fifty-four patients undergoing modified radical mastectomy or total hysterectomy were randomly assigned to remifentanil group or fentanyl group with 27 cases in each group. Anesthesia was induced with propofol (2 mg/kg) and either remifentanil (2 micrograms/kg) or fentanyl (2.5 micrograms/kg), and was maintained with inhalation of nitrous oxide in oxygen (2:1) and a continuous infusion of either remifentanil (0.2 microgram.kg-1.min-1) or fentanyl (0.03 microgram.kg-1.min-1). Depth of anesthesia, hemodynamic changes, recovery profile of anesthesia, postoperative analgesia and adverse reactions were observed. RESULTS: The number of patients exhibited light depth of anesthesia during tracheal intubation and maintenance in the remifentanil group was significantly fewer than that in the fentanyl group (P < 0.05). Hemodynamic changes during intubation, skin incision, maintenance of anesthesia and extubation in the remifentanil group were significantly smaller than those in the fentanyl group (P < 0.05, P < 0.01). The time to opening eyes on command and the time for extubation after surgery were comparable between the two groups. More patients in the remifentanil group required bolus injection of morphine for postoperative pain relief than those in the fentanyl group (P < 0.05). There was no significant difference between the two groups in the aspect of adverse reactions. CONCLUSION: The anesthetic and analgesic effects of remifentanil are more potent than those of fentanyl. Remifentanil can offer superior intraoperative hemodynamic stability compared with fentanyl without compromising recovery from anesthesia.

[Perioperative melatonin secretion rhyme in patients undergoing coronary artery bypass grafting surgery].

OBJECTIVE: To investigate perioperative patterns of melatonin and cortisol secretion rhyme in patients undergoing coronary artery bypass grafting surgery. METHODS: Eleven male patients scheduled for elective coronary artery bypass grafting surgery (CABG) under hypothermic cardiopulmonary bypass (CPB) were enrolled in the study. Anesthesia was induced and maintained with propofol (3 mg.kg-1.h-1) and supplemented with fentanyl (15 micrograms/kg). Blood samples were taken during surgery at specific time-points and every 3 h in the immediate postoperative period and postoperative day 2 and day 3. Plasma melatonin and cortisol levels were measured by radioimmunoassay and enzyme-linked immunosorbent assay respectively. RESULTS: During surgery, plasma melatonin levels were below the minimum sensitivity level but low levels, without circadian variation, were measured during the immediate postoperative period. During postoperative day 2 and day 3, circadian secretion patterns of melatonin were present in 10 patients and showed an inverse correlation with light intensity exposed (r = -0.480, P = 0.01). Plasma cortisol levels in the immediate postoperative period were significantly higher than those before induction of anesthesia (P < 0.01). During postoperative day 2 and day 3, only 3 patients regained circadian secretion of cortisol. CONCLUSIONS: It is concluded that melatonin and cortisol secretion are disrupted during cardiac surgery and in the immediate postoperative period.

[Perioperative anesthetic management for the excision of phaeochromocytoma complicated with catecholamine cardiomyopathy].

OBJECTIVE: To summarize experience of perioperative anesthetic management for patients undergone excision of pheochromocytoma and complicated with catecholamine cardiomyopathy. METHODS: Perioperative anesthetic management for surgical treatment of three cases of pheochromocytoma complicated with catecholamine cardiomyopathy was described and discussed according to literature reports. RESULTS: The catecholamine cardiomyopathy of the three cases presented with left ventricular hypertrophy, congestive cardiac failure and acute myocardial infarction. After removal of the pheochromocytoma under general anesthesia, a prolonged hypotension occurred in all of the three cases. In order to maintain stable hemodynamics, large dose of catecholamine was required after surgery. All of the three patients were survived and discharged. CONCLUSIONS: It is suggested that myocardial dysfunction may be another important factor for the prolonged hypotension after removal of the tumor. Meticulous preoperative assessment of heart function is of primary importance for the management of anaesthesia during surgical procedures.