Liver function assessment by indocyanine green plasma disappearance rate in patients with intra-abdominal hypertension after "non-hepatic" abdominal surgery

Background and objective: Liver function assessment in patients with intra-abdominal hypertension (IAH) after major abdominal surgery is complex and often confounding. Elevated intra-abdominal pressure (IAP) often occurs after major abdominal surgery, and is associated with decreased abdominal blood flow and organ dysfunction, and it could cause abdominal compartment syndrome (ACS), which is a life-threatening condition. Plasma disappearance rate (PDR) of indocyanine green (ICG) and ICG retention rate after 15 min (R15) were used to evaluate liver function and as a prognostic parameter after major abdominal surgery. Methods: In this prospective/observational study, 51 patients were followed in the surgical intensive care unit after major abdominal surgery (operation of the small and large intestine, stomach, pancreas, spleen, or resection of the abdominal aorta), 29 had IAH. The PDR-ICG and R15 were analyzed 24 h after surgery concurrently with IAP, APP, bilirubin, AST, ALT, prothrombin time, albumin, cardiac index, arterial lactate, oxygen delivery, MAP (mean arterial pressure), APACHE II (acute physiology and chronic health evaluation), SOFA (sequential organ failure assessment), and SAPS II (simplified acute physiology score). IAH has been defined as a peak intra-abdominal pressure (IAP) value of >= 12 mmHg, at a minimum, as two standardized measurements obtained 1-6 h apart. Results: The PDR-ICG measured 24 h after surgery was not different among groups (20.95% [SD = 10.34] vs 25.40% [SD = 7.42]), p = .094. ICG R15 was significantly higher in patients with IAH, 11.10% [SD = 13.82] vs 8.30 [SD = 11.46], p < .05, respectively. The PDR/ICG value was significantly lower in non-survivors than survivors (16.82 [SD = 10.87] vs 24.35 [SD = 8.48], p < .05). Conclusions: The results suggest that PDR/ICG and ICG R15 are useful dynamic tests for evaluation of complex liver function and survival prediction after major abdominal surgery in patients with IAH.