Vasopressin levels in major head and neck surgery.

In an effort to further understand the perioperative intravascular volume status of major head and neck surgery patients, serum antidiuretic hormone (ADH) and osmolality levels were assessed at four perioperative junctures. Thirty-five major head and neck surgical patients were randomly selected for examination with placement of a central venous pressure monitor. Serum osmolality and serum vasopressin levels were obtained at four junctures perioperatively. ADH levels were lower both after patients were anesthetized and five hours into the procedure than at either baseline or 24 hours after the end of the procedure. ADH levels after patients were anesthetized did not differ from those at five hours into the procedure, nor did ADH levels at baseline differ from those 24 hours after the end of the procedure. In addition, osmolality levels did not change over time. Additional analyses examining relationships between preoperative, intraoperative, and postoperative characteristics and ADH levels after patients were anesthetized and five hours into the procedure, as well as changes from baseline at these times and the baseline levels themselves, detected no significant relationships. This study provides information about the perioperative intravascular volume status of major head and neck surgery patients which may be important to intraoperative care, especially to decisions regarding invasive intraoperative fluid monitoring. Specifically, the data provide additional evidence against the need for the routine placement of central venous catheters to guide fluid administration during major head and neck surgery.