Consideration of the optimal epidural fentanyl doses in abdominal surgery.
OBJECTIVE
To determine an optimal dose of epidural fentanyl in open abdominal surgery by examining the effects of different doses of epidural fentanyl in combination with or without low concentration of lidocaine on hemodynamic and endocrine responses to surgical stress.


METHODS
Prospective, randomized study.


METHODS
University hospital.


METHODS
40 ASA physical status I and II patients scheduled for elective abdominal surgery including gastrectomy (n = 20), colectomy (n = 10), liver tumor resection (n = 2), pancreatectomy (n = 3), pancreaticoduodenectomy (n = 1), low anterior resection (n = 3), and cholecystectomy (n = 1).


METHODS
Patients were randomly allocated to one of two groups: epidural fentanyl with 0.5% lidocaine (Group L + F; n = 25) or epidural fentanyl alone (Group F; n = 15). Both two groups were divided into subgroups; in Group L + F, epidural fentanyl was administered as doses of 0, 0.3, 1, 3, and 5 micrograms/kg in 5 patients each. In Group F, epidural fentanyl was administered as doses of 1, 3, and 5 micrograms/kg in 5 patients each. Hemodynamic data and plasma catecholamine concentrations were compared between before the epidural injection and immediately after peritoneal incision.


RESULTS
There was no difference in mean arterial pressure (MAP) and heart rate (HR) between Group L + F and Group F at the time before epidural administration of fentanyl, 20 minutes after epidural fentanyl, and immediately after peritoneal incision. However, there were significant decreases in MAP immediately after skin incision in epidural fentanyl 0 and 3 micrograms/kg in Group L + F patients and also in epidural fentanyl 1 and 3 micrograms/kg in Group F patients. HR significantly decreased in epidural fentanyl 5 micrograms/kg of Group L + F at peritoneal incision (p < 0.05). Plasma epinephrine decreased significantly in fentanyl 3 and 5 micrograms/kg in Group L + F immediately after peritoneal incision (p < 0.05), whereas the increase in norepinephrine was significant in Group F (p < 0.01). Plasma dopamine significantly increased only in fentanyl 1 microgram/kg in Group F (p < 0.05).


CONCLUSIONS
Epidural fentanyl 3 micrograms/kg with 0.5% lidocaine may be most adequate for laparotomy because these doses caused neither bradycardia nor increments of norepinephrine perioperatively.
Arakawa
M
M
Department of Anesthesiology, Kitasato University School of Medicine, Kanagawa, Japan.
Hoka
S
S
D000005:Abdomen / Q000601:surgery*; D000767:Anesthesia, Epidural; D019162:Anesthetics, Combined / Q000008:administration & dosage / Q000009:adverse effects; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects; D000779:Anesthetics, Local; D002395:Catecholamines / Q000097:blood; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000009:adverse effects; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008012:Lidocaine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013312:Stress, Physiological / Q000097:blood / Q000209:etiology / Q000503:physiopathology
D019162:Anesthetics, Combined; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D002395:Catecholamines; D008012:Lidocaine; D005283:Fentanyl