Preoperative evaluation

Table 176-1 lists some of the relevant physiologic consequences of liver failure and the consequences that may occur during liver transplantation. Prior to presenting for transplantation, candidates are screened for comorbid cardiopulmonary conditions: a resting echocardiogram assesses cardiac function and allows estimation of pulmonary artery pressures. A bubble test (injection of agitated saline while monitoring for echo-contrast in the right side of heart chambers) can also be performed; delayed appearance of the contrast agent suggests that the patient may have hepatopulmonary syndrome. If the patient has risk factors for coronary artery disease (∼40%-50% of adult patients), noninvasive testing is frequently performed, often by dobutamine stress echocardiography, because patients with significant coronary artery disease have poor peritransplant outcomes.

Renal dysfunction often accompanies end-stage liver disease from hepatorenal syndrome, acute tubular necrosis, or a combination of both. In a patient requiring renal dialysis or continuous renal replacement therapy, consideration should be given to performing continuous dialysis or ultrafiltration in the operating room if problems managing volume or electrolytes are anticipated. Washing red blood cells prior to transfusion to reduce potassium may also be helpful.