Growth hormone (GH) secretion is regulated by various
hormones or
neurotransmitters, including
gamma-aminobutyric acid. The aim of this study was to determine the
propofol requirement in patients with GH-secreting
pituitary tumors undergoing transsphenoidal surgery.
General anesthesia was induced in 60 patients with GH-secreting
tumors (GH group,
n = 30) or nonfunctioning
pituitary tumors (NF group,
n = 30) using an effect-site target-controlled intravenous
propofol infusion. The effect-site concentrations were recorded at both a
loss of consciousness and a bispectral index (BIS) of 40, along with the effect-site concentration after extubation, during emergence from the
anesthesia. The effect-site concentration of
propofol was higher in the GH group than in the NF group at a
loss of consciousness and a BIS of 40 (4.09 ± 0.81 vs. 3.58 ± 0.67, p = 0.009 and 6.23 ± 1.29 vs. 5.50 ± 1.13, p = 0.025, respectively) and immediately after extubation (1.60 ± 0.27 vs. 1.40 ± 0.41, p = 0.046). The total doses of
propofol and
remifentanil during
anesthesia were comparable between the groups (127.56 ± 29.25 vs. 108.64 ± 43.16 µg/kg/min, p = 0.052 and 6.67 ± 2.89 vs. 7.05 ± 1.96 µg/kg/h, p = 0.550, respectively). The
propofol requirement for the induction of a
loss of consciousness and the achievement of a BIS of 40 is increased during the induction of
general anesthesia in patients with GH-secreting
tumors.