Ionized calcium levels during liver transplantation.

Plasma ionized calcium and total calcium concentrations were measured during 26 liver transplant operations. The level of ionized calcium decreased during the early part of the operation, reaching its lowest point during the anhepatic period, but rose again after revascularization of the new liver. Calcium chloride was given with the aim of reversing these decreases, which were associated with the use of blood products preserved in citrate-phosphate-dextrose anti-coagulant-containing adenine (CPD-A). Ionic hypocalcaemia is a result of intra-operative citrate loading in the presence of poor or absent (during the anhepatic phase) liver function; aggressive correction of low ionized calcium levels, especially during the early stages of the operation, is required to prevent this effect.

The prevention of renal impairment in patients undergoing orthotopic liver grafting by infusion of low dose dopamine.

Administration of low dose dopamine (2.0 micrograms/kg/minute) begun before surgery in patients undergoing liver transplantation decreases the incidence of postoperative renal impairment. Thirty-four consecutive patients in the Cambridge/King's College Hospital liver transplantation series were studied. Nineteen patients (21 transplant operations) received prophylactic low dose dopamine throughout the operative and early postoperative period, while 15 patients (15 transplant operations) received dopamine only when clinically indicated for incipient renal failure or as an inotropic agent. In the prophylactic dopamine group, only two transplant operations (9.5%) were complicated by renal impairment, whereas in the other group, 10 patients (67%) developed renal impairment (p = 0.001); of these, four developed acute renal failure (27%). Comparison of seven pairs of patients, matched for age, sex, diagnosis, operative blood loss and operative hypotension (one group receiving dopamine, the other not), revealed a significantly higher urine output in the first 24 hours and creatinine clearance 24-48 hours after surgery (p less than 0.05) in those treated prophylactically. In view of these findings, we would recommend that consideration be given to the prophylactic use of dopamine in patients undergoing orthotopic liver transplantation.

[Liver transplantation in children. Blood transfusion and metabolic disorders]. / Transplantation hépatique chez l'enfant. Transfusion sanguine et troubles métaboliques.

Metabolic disorders during hepatic transplantation can be partly induced by blood transfusion. A retrospective survey of perioperative biological data recorded in patients under 18 years of age having liver transplantation was performed. Blood transfusion was also studied. For this evaluation, patients were divided in a paediatric group I (n = 20; mean age: 3.7 years) and an adolescent group II (n = 11; mean age: 14.3 years). Blood transfusion was significantly (p less than 0.05) more important in group I (302 +/- 286 ml X kg-1) than in group II (148.5 +/- 156 ml X kg-1). Autotransfusion of washed red cells was performed in six patients, allowing a mean 17 +/- 7% saving in blood transfusion. Severe hypernatraemia over 152 mmol X l-1 due to blood transfusion was observed only in five patients in group I. Hyperglycaemia increasing till the revascularization of the new liver was constant in both groups, but significantly more pronounced in group II. Cardiac arrest occurred twice in group I at initial revascularization. In group I, children with biliary atresia were not significantly different from the others for the duration of operation and the volume of blood transfusion; however the latter was more abundant. Conversely, in group II, the duration of operation was longer (p less than 0.05) in patients with previous abdominal surgery than in others. Finally the paediatric group differs from the adolescent group by obvious differences in anaesthesia and intensive care and specifically in hepatic transplantation by larger volume of blood transfusion leading to severe hypernatraemia. In further studies, adolescents should be distinct from the paediatric group and included in the adult group.

Autotransfusion, an experience of seventy six cases.

The use of autotransfusion with a centrifugal cell washer in a series of 76 cases is reviewed. The requirement for bank blood is reduced in patients with major operative haemorrhage, although it does not appear to be able to provide the main source of blood replacement in such cases. The major impact of autotransfusion may lie in reducing the amount of blood that needs to be crossmatched for elective operations. Nevertheless in certain cases its use can be life saving.

Atracurium infusion in liver transplantation.

A continuous infusion of atracurium was used to provide neuromuscular blockade in 25 adult patients undergoing liver transplantation following atracurium, suxamethonium or vecuronium for intubation. Blockade was monitored by recording evoked electromyographic response and maintained with a mean infusion rate of 0.38 +/- 0.14 mg kg-1 h-1 during 306 +/- 80 min of operation. Atracurium requirements appeared to be less during the anhepatic period and greater after removal of the vascular clamps on the new liver. No instances of arterial hypotension or anaphylactoid reactions attributable to atracurium were reported. It can be concluded that a continuous infusion of atracurium is a safe, effective and convenient technique of ensuring neuromuscular blockade during liver transplantation, at a rate of infusion no different from that needed in patients with normal hepatic function.

Anesthesia for hepatic transplantation: cardiovascular and metabolic alterations and their management.

We studied the cardiovascular and metabolic changes occurring during orthotopic liver transplantation in nine patients. The operative management of these patients can be divided into an initial dissection phase, an anhepatic phase when the hepatic artery, portal vein, and inferior vena cava are cross-clamped, and the phase after the release of these clamps. On clamping the inferior vena cava, the systolic arterial pressure decreased from 134 +/- 9 to 104 +/- 8 mm Hg, the pulmonary artery pressure decreased from 25 +/- 4 to 17 +/- 4 mm Hg, the mean pulmonary wedge pressure decreased from 11.9 +/- 1.9 to 6.8 +/- 1.2 mm Hg, and cardiac index decreased from 5.3 +/- 0.3 to 2.7 +/- 0.2 L X min-1 X m-2. There were compensatory increases in systemic vascular resistance from 806 +/- 52 to 1448 +/- 109 dyne X cm X sec-5 and in pulmonary vascular resistance from 78 +/- 13 to 122 +/- 25 dyne X cm X sec-5. Removal of these clamps was followed by an initial depression in cardiac output that returned to preclamping values. Profound metabolic alterations were encountered during these phases. Hydrogen ion concentration increased from a mean of 39 +/- 2 to 45 +/- 2 nmol/L during cross-clamping, with a further increase to 55 +/- 3 nmol/L after the initial perfusion of the new liver. Serum potassium levels increased significantly only on release of the clamps, from a mean of 3.8 +/- 0.3 to a peak of 5.3 +/- 0.6 mmol.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaesthetic vapour concentrations in the EMO system.

Measurements of the vapour concentrations delivered by the EMO and Oxford Miniature Vaporizers (OMV) were made with both continuous (plenum mode) and intermittent (drawover mode) air flows. Leakage of ether, halothane and trichloroethylene vapours through the corrugated elephant tubing was also measured. Both vaporizers performed most consistently with the intermittent flows for which they were designed. Outputs were minimal at very low carrier gas flows, reached their greatest at the higher settings in the middle flow range and tended to be low at the highest flows. These effects were far more notable with continuous than with intermittent flows. Minimal amounts of ether were lost through the tubing but halothane losses were appreciable, while losses of trichloroethylene were enough to reduce the concentrations available to the patient. The EMO is not suitable for plenum use with carrier gas flows below about 10 litres/min. The OMV is a useful plenum vaporizer although the outputs are generally lower than indicated at higher flows.

Improved survival after orthotopic liver grafting.

A total of 108 orthotopic liver transplants have been carried out in the Cambridge/King's College Hospital series. Over 13 years, changes in patient selection, immunosuppression, and surgical and anaesthetic techniques have led to a steady improvement in results. Results obtained in the last 22 patients indicated that over half survive for one year. Although at considerable risk during the operation, patients with non-malignant cirrhotic diseases who survive one year have a good long-term chance of survival