Ag. Jensen et al., A COMPARISON OF PROPOFOL AND ISOFLURANE ANESTHESIA - THE NEED FOR EPHEDRINE AND GLYCOPYRROLATE, European journal of anaesthesiology, 12(3), 1995, pp. 291-299
Sixty patients, ASA I-III, presenting for elective colonic surgery wer
e studied to assess the stability of blood pressure and heart rate dur
ing anaesthesia with three equally potent anaesthetic techniques. Pati
ents in group I (n=20) received thiopentone induction, isoflurane and
nitrous oxide; patients in group II (n=20) received total intravenous
anaesthesia with propofol; and patients in group III (n=20) received i
ntravenous propofol supplemented with nitrous oxide. Fentanyl and vecu
ronium were used in all three groups. The depth of anaesthesia was jud
ged on clinical signs of adequate anaesthesia. Episodes of bradycardia
(heart rate <50 beats min(-1)), tachycardia (heart rate >90 beats min
(-1)), hypotension (mean arterial pressure greater than or equal to 30
% below pre-operative blood pressure) or hypertension (mean arterial p
ressure greater than or equal to 30%, or systolic blood pressure > 15
mmHg, above pre-operative value) were recorded when lasting > 5 min. A
ny use of ephedrine or glycopyrrolate given to correct hypotension or
bradycardia was documented: In group II, significantly more patients w
ere given ephedrine (P<0.01) to treat hypotension. The drug was admini
stered after intubation but before skin incision in the majority of ca
ses (9/11). Glycopyrrolate was given to significantly more patients in
group III (P<0.025) to treat bradycardia, and in 21 of a total of 34
patients given glycopyrrolate it was administered before surgery. With
the use of these additional drugs, there were no differences in the n
umber of patients with 5 min episodes of hypotension, hypertension, ta
chycardia or bradycardia. The intravenous techniques using propofol wi
th or without nitrous oxide required more pharmacological intervention
s before surgery than the regular isoflurane-based technique in order
to maintain a stable blood pressure level and heart rate during this p
eriod.