Examination of the usefulness of non-invasive stroke volume variation monitoring for adjusting fluid supplementation during laparoscopic adrenalectomy in patients with pheochromocytoma.

PURPOSE OF THE STUDY The measurement of stroke volume variation (SVV) using the FloTrac™ system (Edwards Lifescience, USA) is useful to estimate cardiac preload. We evaluated the benefits of SVV monitoring for adjusting fluid supplementation during laparoscopic adrenalectomy under anesthesia in patients with pheochromocytoma. SUBJECTS AND METHODS Among 10 patients who underwent laparoscopic adrenalectomy for pheochromocytoma in our institution from June 2004 to December 2009, SVV was not monitored in 5 patients (group I) and in the other 5 patients (group II), SVV monitoring was performed. Subject age, height and body weight, total volume of fluid supplemented, blood loss, urine output and net fluid in-out balance during the procedure were retrospectively assessed. In those with SVV monitoring, infusion volume was adjusted for SVV less than 13%. RESULTS There were significant differences in the patient age and body weight between the two groups (group I: 64.2 years old and 55.1 kg; group II: 43.6 years old and 71.7 kg). Both total infusion volume and urine output were significantly higher in group I compared with group II (5,610 vs. 2,400 ml and 1,125 vs. 750 ml, respectively). Total blood loss was similar between the two groups. Values of the net fluid balance divided by the body weight and total anesthesia period (hr) were significantly lower in group II compared with group I (I; +13.2 in group I and +6.2 in group II, ml/kg/hr). CONCLUSIONS These data suggest that SVV monitoring is helpful to estimate the optimal volume for fluid supplementation and could prevent excessive fluid infusion during surgical procedures.