Induction with propofol target-concentration infusion vs. 8% sevoflurane inhalation and alfentanil in hypertensive patients.

Haemodynamic parameters during an inhalation induction with 8% sevoflurane were compared with those obtained with a target-controlled infusion of propofol in 50 hypertensive patients in a prospective randomised study. Heart rate and arterial pressure were recorded continuously. End-tidal sevoflurane and nitrous oxide concentration, SpO2 and bispectral index (BIS) were also collected from the beginning of anaesthesia until 8 min after tracheal intubation. Patients either received 4 mg.l-1 target-concentration propofol or performed a vital capacity inhalation of 8% sevoflurane in a high flow of oxygen (8 l.min-1) supplemented with 50% nitrous oxide at loss of consciousness. As soon as BIS was < 60, 20 microg.kg-1 alfentanil and 0.6 mg.kg-1 rocuronium were injected and orotracheal intubation was then performed 1 min later. Thereafter, the end-tidal concentration of sevoflurane was reduced to 1.3 minimum alveolar concentration (MAC). Hypotension was defined as a 30% decrease in arterial pressure and was treated with repeated 3-mg boluses of ephedrine. When 12 mg ephedrine was unable to correct hypotension, the concentration of propofol was reduced by 1 mg.l-1 and that of sevoflurane by 0.5%. Hypotension occurred in 22 patients in the sevoflurane group and 21 in the propofol group, and hypertension occurred in two and three patients in each group, respectively. The maximal reduction in mean (SD) arterial pressure was similar in the sevoflurane (45 (4) mmHg) and propofol (41.3 (2.6) mmHg) groups, as were the ephedrine requirements (9.6 (1.1) vs. 9.1 (1.1) mg, sevoflurane vs. propofol, p > 0.05), the duration of hypotension (276 (37) vs. 292 (38) s, sevoflurane vs. propofol, p > 0.05), and the number of hypotensive episodes or anaesthetic changes and depth of anaesthesia. Nevertheless, heart rate was lower during the 8 min following tracheal intubation in the sevoflurane group. In both groups, the duration of hypotension was easily controlled either by ephedrine or by adjusting the anaesthetic concentrations. Overall, haemodynamic tolerance appears to be similar in the two techniques. Because hypotension occurred after alfentanil in most patients, this study questioned which is the best opioid dose, if any, to associate with propofol or sevoflurane for the induction in hypertensive patients.