Correlations of preoperative hormonal changes with propofol and remifentanil requirements in pituitary adenoma patients

ABSTRACT

BACKGROUND: Anesthetic requirements are affected by the preoperative levels of some hormones. This study investigated to identify the hormonal status such as plasma level and maximal secretary capacity correlating with propofol and remifentanil requirements in pituitary adenoma patients who show various hormonal secretory states perioperatively. METHODS: From 51 adult female pituitary adenoma patients, preoperative basal values and maximal stimulated levels of various hormones related to the axis of hypothalamus-pituitary-target organs on combined pituitary function test were recorded. Total intravenous anesthesia using target controlled infusion with propofol and remifentanil was administered. The effect-site concentration (Ce) of propofol reaching anesthetic induction and the consumed dosages of propofol and remifentanil during operation were measured. Anesthetic maintenance was controlled within 30% of preanesthetic hemodynamic variables by remifentanil and within ranges of BIS 45 +/- 10 by propofol. Spearman correlations between hormonal status and anesthetic requirements such as propofol Ce for induction, total consumed doses of propofol and remifentanil were performed with a statistical significance at P of 0.05. RESULTS: The preoperative basal level of ACTH was correlated positively with propofol induction Ce and maintenance dose, and the maximal secretory capacity of prolactin also correlated positively with propofol induction Ce. Remifentanil consumption dose was not related with any hormones measured regardless of either preoperative basal levels or maximal secretory levels. CONCLUSIONS: Propofol requirements may be related with preoperative plasma level of ACTH or maximal secretory capacity of prolactin.