Sevoflurane improves the neuroendocrine stress response during laparoscopic pelvic surgery

Stress response to surgery is modulated by several factors, including magnitude of the injury, type of procedure (e.g., laparoscopy vs laparotomy) and type of anesthesia. Our purpose was to compare intra- and postoperative hormonal changes during isoflurane vs sevoflurane anesthesia, in a clinical model of well defined operative stress (laparoscopic pelvic surgery).

In this prospective randomized clinical study, 20 women requiring laparoscopic pelvic surgery for benign ovarian cysts received either a standard isoflurane plus fentanyl (Group A) or sevoflurane plus fentanyl anesthesia (Group B). Blood samples were collected preoperatively, 30 min after the beginning of surgery, at the end of surgery after extubation, and two and four hours after the end of surgery. Intra- and postoperative plasma levels of norepinephrine, epinephrine, adrenocorticotropic hormone (ACTH), cortisol, growth hormone (GH) and prolactin (PRL) were measured.

Catecholamine levels and postoperative pain were similar in both groups. Nonetheless, in comparison to Group A, Group B showed a significant decrease of ACTH, cortisol and GH levels (A vs B at the end of surgery: ACTH 160 +/- 45 vs 100 +/- 40 pg.mL(-1); cortisol 45 +/- 8 vs 23 +/- 7 microg.dL(-1); GH 3 +/- 2 vs 0.8 +/- 0.4 ng.mL(-1); P < 0.001 for all), but enhanced PRL levels (A vs B, at 30 min after the beginning of surgery: 139 +/- 54 vs 185 +/- 22 ng.mL(-1); at the end of surgery: 100 +/- 27 vs 141 +/- 45 ng.mL(-1); P < 0.001 for both).

In the clinical setting of low stress laparoscopic surgery, the type of volatile anesthetic significantly affected the stress response; the changes associated with sevoflurane suggested a more favourable metabolic and immune response compared to isoflurane.