T. Inada et al., HEMODYNAMIC COMPARISON OF SEVOFLURANE AND ISOFLURANE ANESTHESIA IN SURGICAL PATIENTS, Canadian journal of anaesthesia, 44(2), 1997, pp. 140-145
Purpose: To compare the haemodynamic responses to surgical incision du
ring sevoflurane and isoflurane anaesthesia and to compare the haemody
namic effects of each anaesthetic alone with those obtained using an e
quipotent mixture of each anaesthetic plus N2O during steady-state sur
gical stimulation. Methods: Twenty-four patients undergoing gastrectom
y were randomized to receive sevoflurane (n = 12) or isoflurane (n = 1
2). At 1.5 MAC, haemodynamic measurements were performed before and af
ter surgical incision. During intestinal anastomosis, patients in each
group were given (in random order) either 1.5 MAC of the designated a
naesthetic or 0.85 MAC of the volatile plus 0.65 MAC N2O. Haemodynamic
measurements were repeated under each condition. Results: One patient
in the sevoflurane group and two in the isoflurane group were exclude
d from the incision study because of hypotension. in both groups, inci
sion increased the heart rate (HR), mean arterial pressure, mean pulmo
nary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCW
P), cardiac index, and systemic vascular resistance index (SVRI). Ther
e were no intergroup differences in the effects of incision. Inclusion
of N2O resulted in an increase of MPAP (P < 0.05) in both groups, an
increase of central venous pressure and PCWP in the sevoflurane group
(P < 0.005), and a decrease of HR (P < 0.005) and an increase of SVRI
(P < 0.05) in the isoflurane group. There were no intergroup differenc
es in the effects of N2O. Conclusions: At 1.5 MAC, sevoflurane and iso
flurane do not prevent the haemodynamic response to incision. The haem
odynamic effects of each volatile anaesthetic with N2O are minimal com
pared with those of equi-MAC volatile alone.