The effect of liver surgery and fluid strategy on renin activity and aldosterone and anti-diuretic hormone levels: a secondary analysis of the GALILEO trial

Background It is unknown whether liver surgery leads to increased RAAS activity and anti-diuretic hormone (ADH) levels and subsequent fluid accumulation. Furthermore, it is unknown whether the peri-operative fluid strategy changes this effect. Methods This is a pre-planned post hoc analysis of a randomised controlled trial which compared restrictive (n = 20) versus liberal fluid strategy (n = 20) in patients undergoing liver surgery. Primary outcomes for the current study were the difference in hormone levels after anaesthesia induction and after liver resection. Fluid overload was defined as a ≥10% increase in weight. Results Renin activity (6 [2.1–15.5] vs. 12 [4.6–33.5]) and ADH levels (6.0 [1.7–16.3] vs. 3.8 [1.6–14.7]) did not differ significantly before and after resection. However, aldosterone levels were significantly higher after resection (0.30 [0.17–0.49] vs. 0.69 [0.31–1.21] ). Renin activity and aldosterone levels did not differ between the groups. ADH was significantly higher in the restrictive strategy group (1.6 [1.1–2.1] vs 5.9 [3.8–16.0]). No differences in hormone levels were found in patients with and without fluid overload. Discussion Aldosterone levels increased after liver surgery but renin activity and ADH levels did not. ADH levels were higher in the restrictive group. Development of post-operative fluid overload was not associated with RAAS activity or ADH levels.