Assessment of Graft Liver Function During Liver Transplantation SC 梁祥光
What are we concerned about during liver transplantation?
Are the conditions of the patient stable? • Does the transplanted liver work?
What kinds of monitors or predictors are available?
For monitoring of vital signs: ECG, Swan-Ganz, CVP, A-line, oximeter, electrolyte, acid-base, urine output, body temperature
With regard to liver function, which predictors can be useful?
The functions of the liver • catabolic & anabolic functions (carbohydrate, fat & protein metabolism) • production of bile • production & execretion of bilirubin • immunological functions(cytokines & interferons) • scavenging & filtration of endotoxins & bacteria • storage of vitamin B12 & glycogen • biotransformation & elimination of drugs & xenobiotics
Ideal agents • nontoxic & lack pharmacological effects • administration • rate-determining steps of elimination • route of elimination • measurement • protein-binding • cost • reliable assay • generally available Gao L et al, Anaesth Intens Care 2000; 28: 375-85
Predictors or markers of liver functions(1) Hepatologist • prothrombin ratio • plasma enzymes(GOT, GPT) • bilirubin • albumin
Predictors or markers of liver functions(2) Anaesthetist • capacity-limited, binding-insensitive hepatic elimination neuromuscular blocking agent, aminopyrine, caffeine • capacity-limited, binding-sensitive hepatic elimination erythromycin • flow-limited elimination ICG, galactose J. W. Sear, Br. J. Anaesth. 2002 88: 757-760.
ICG • 95% albumin-binding • liver function & blood flow • IV injection(0.5mg/kg), blood sample(2ml at 5min intervals for 15-30min) • ICG elimination rate & graft liver function ICG clearance>200mi/min good liver function ICG clearance<200mi/min death, prolonged intensive care, retransplantation Gao L et al, Anaesth Intens Care 2000; 28: 375-85
Rocuronium(1) Aminosteroidal muscle relaxant Elimination Major(80%): liver Minor: kidney Metabolite: 17-desacetylrocuronium Assay train-of-four gas chromatographic-mass spectrometry L Gao, Br. J. Anaesth. 2002 88: 764-770
Rocuronium(2) What is observed in the administration of rocuronium? • pleohepatic phase rocuronium’s clearance is slightly less than that of patient with liver disease undergoing nontransplantation surgery and healthy control subjects • anhepatic phase rocuronium’s clearance is similar to that in the pleohepatic phase Dennis M Fisher et al, anesthesiology 1997; 86:1306-16
Rocuronium(3) • neohepatic phase decreased plasma rocuronium concentration compared with that during the anhepatic phase L Gao, Br. J. Anaesth. 2002 88: 764-770
Rocuronium(4) • postoperative outcome Fig 1 Percentage change in plasma recuronium concentration between neohepatic and anhepatic phases in patients who died after surgery and those who survived. L Gao, Br. J. Anaesth. 2002 88: 764-770
What can we do in the future? Prediction of prognosis? ↓ Sensitivity and specificity? ↓ D/D(surgical procedure, rejection)? ↓ Management? ↓ Outcome?