Stroke Volume Variation in Hepatic Resection: A Replacement for Standard Central Venous Pressure Monitoring

Abstract

Central venous pressure (CVP) is the standard method of volume status evaluation during hepatic resection. CVP monitoring requires preoperative placement of a central venous catheter (CVC), which can be associated with increased time, cost, and adverse events. Stroke volume variation (SVV) is a preload index that can be used to predict an individual's fluid responsiveness through an existing arterial line. The purpose of this study was to determine if SVV is as safe and effective as CVP in measuring volume status during hepatic resection. Two cohorts of 40 consecutive patients (80 total) were evaluated during hepatic resection between December 2010 and August 2012. The initial evaluation group of 40 patients had continuous CVP monitoring and SVV monitoring performed simultaneously to establish appropriate SVV parameters for hepatic resection. A validation group of 40 patients was then monitored with SVV alone to confirm the accuracy of the established SVV parameters. Type of hepatic resection, transection time, blood loss, complications, and additional operative and postoperative factors were collected prospectively. SVV was calculated using the Flotrac™/Vigileo™ System. The evaluation group included 40 patients [median age 62 (29-82) years; median body mass index (BMI) 27.7 (16.5-40.6)] with 18 laparoscopic, 22 open, and 24 undergoing major (≥3 segments) hepatectomy. Median transection times were 43 (range 20-65)min, median blood loss 250 (range 20-950) cc, with no Pringle maneuver utilized. In this evaluation group, a CVP of -1 to 1 significantly correlated to a SVV of 18-21 (R (2)=0.85, p<0.001). The validation group included 40 patients [median age 61 (35-78) years; median BMI 28.1 (17-41.2)], with 24 laparoscopic, 16 open, and 33 undergoing major hepatectomy. Using a SVV goal of 18 to 21, median transection time was 55 (25-78) min, median blood loss of 255 (range 100-1,150) cc, again without the use of a Pringle maneuver. SVV can be used safely as an alternative to CVP monitoring during hepatic resection with equivalent outcomes in terms of blood loss and parenchymal transection time. Using SVV as a predictor of fluid status could prove to be advantageous by avoiding the need for CVC insertion and therefor eliminating the risk of CVC related complications in patients undergoing hepatic resection.