Remifentanil and fentanyl during anaesthesia for major abdominal and gynaecological surgery. An open, comparative study of safety and efficacy.
BACKGROUND
and objective This open, multicentre study compared the efficacy and safety of remifentanil with fentanyl during balanced anaesthesia with 0.8% isoflurane (end-tidal concentration) for major abdominal and gynaecological surgery, and the efficacy and safety of remifentanil for pain management in the immediate postoperative period.


METHODS
Two-hundred and eighty-six patients were randomized to receive remifentanil 1 microg kg(-1) followed by 0.2 microg kg(-1) min-1 (n=98), remifentanil 2 microg kg(-1) followed by 0.4 microg kg(-1) min(-1) (n=91) or fentanyl 3 microg kg(-1) (n=97) at induction. Thereafter, the study opioids and isoflurane were titrated to effect during the operation.


RESULTS
Compared with fentanyl, remifentanil 2 microg kg(-1) followed by 0.4 microg kg(-1) min(-1) reduced the incidence of response to tracheal intubation (30% vs. 13%, P < 0.01), skin incision (33% vs. 4%, P < 0.001) and skin closure (11% vs. 3%, P < 0.05), respectively. Patients receiving remifentanil 1 microg kg(-1) followed by 0.2 microg kg(-1) min(-1) had fewer responses to skin incision than the fentanyl group (12% vs. 33%, P < 0.001), but the incidences of response to tracheal intubation and skin closure were similar. Significantly fewer patients in both remifentanil groups had > or = 1 responses to surgical stress intraoperatively compared with fentanyl (68% and 48% vs. 87%, P < 0.003). The mean isoflurane concentrations required were less in both remifentanil groups compared with the fentanyl group (0.1%, P=0.05). In remifentanil-treated patients, continuation of the infusion at 0.1 microg kg(-1) min(-1) with titration increments of +/- 0.025 microg kg(-1) min(-1) was effective for the management of immediate postoperative pain prior to transfer to morphine analgesia. However, a high proportion of patients experienced at least moderate pain whilst the titration took place.


CONCLUSIONS
Anaesthesia combining isoflurane with a continuous infusion of remifentanil was significantly more effective than fentanyl at blunting responses to surgical stimuli. Significantly fewer patients responded to tracheal intubation with remifentanil at 0.4 microg kg(-1) min(-1), supporting the use of a higher initial infusion rate before intubation. Both remifentanil and fentanyl were well-tolerated, with reported adverse events typical of mu-opioid agonists.
Sneyd
J R
JR
Department of Anaesthesia, Derriford Hospital, Plymouth, PL6 8DH, Devon, UK. rsneyd@pms.ac.uk
Camu
F
F
Doenicke
A
A
Mann
C
C
Holgersen
O
O
Helmers
J H
JH
Appelgren
L
L
Noronha
D
D
Upadhyaya
B K
BK
D000005:Abdomen / Q000601:surgery*; D000328:Adult; D000762:Anesthesia Recovery Period; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000009:adverse effects; D013509:Gynecologic Surgical Procedures; D006801:Humans; D007530:Isoflurane; D008297:Male; D010100:Oxygen / Q000097:blood; D010149:Postoperative Pain / Q000453:epidemiology / Q000517:prevention & control; D010880:Piperidines / Q000008:administration & dosage / Q000009:adverse effects; D000077208:Remifentanil; D015656:Respiratory Mechanics / Q000187:drug effects / Q000502:physiology
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D010880:Piperidines; D007530:Isoflurane; D000077208:Remifentanil; D010100:Oxygen; D005283:Fentanyl