Haemodynamic changes associated with portal triad clamping are suppressed by prior hepatic pedicle infiltration with lidocaine in humans

Portal triad clamping (PTC) reduces venous return of blood to the heart. Ho wever, the decrease in cardiac index (CI) is associated with an unexpected increase in mean arterial pressure (MAP) and the 40% increase in systemic v ascular resistance is greater than anticipated in compensation for the 10% decrease in CI. We hypothesized that a reflex elicited in the peritoneum ac counted for this unanticipated haemodynamic response. Twenty patients under going liver resection were allocated randomly to have hepatic pedicle infil tration before PTC with either lidocaine 200 mg or placebo. MAP was recorde d, and plasma osmolality and plasma concentrations of vasopressin, epinephr ine, norepinephrine, dopamine, renin and endothelin were measured. After PT C, MAP increased significantly in the placebo group but decreased significa ntly in the lidocaine group. Plasma concentrations of vasopressin, epinephr ine and norepinephrine increased significantly in the placebo group. Plasma concentrations of vasopressin decreased significantly in the lidocaine gro up, while plasma concentrations of epinephrine and norepinephrine were unch anged. A subsequent study in eight patients found that neither haemodynamic nor hormonal changes associated with PTC in the placebo group were altered by administration of lidocaine 200 mg i.m. before PTC.