Energy expenditure (EE) and substrate utilization (SU) in the perioperative period in orthotopic liver transplantation (OLTX).

12 patients were investigated with IC (Datex, Deltatrac) preoperatively and during the surgical procedure of OLTX, VO2, VCO2 were continuously measured and RQ, EE and SU were calculated considering the different periods of the procedure: preoperative resting EE: (PREE), anaesthesiological procedures (ANEE), liver preparation EE (LPEEE), liver removal EE (LREE), anhepatic phase EE (APEE), reperfusion, EE (RPEE) and end of operation EE (EOEE). EE were expressed as % respect value calculated with H.B. (Harris-Benedict) formula. Data were analyzed with Student T-test and p < 0.01** or < 0.05* PREE is typical in end stage liver disease with low RQ values and increased EE. Energy production depends on lipid utilization since liver gluconeogenesis and glycogen stores are impaired. Anesthesia reduces energy needs and production up to 50% of the preoperative values, reducing VO2 more than VCO2 and therefore an augmented RQ value over 1.0. SU analysis indicates an increased glucose and aminoacid utilization coupled with high nitrogen catabolism that continues in the postoperative period (from 0.08 0.01 gN/kg b.w. to 0.20 0.06 gN/kg b.w.). When the new liver is reperfused, VO2 increases more than VCO2 indicating the risk of reperfusion injury.