Parenteral
analgesics are still diffusely administered for
postoperative pain after major liver resection, while
epidural analgesia is widely criticized because of possible changes in the postoperative coagulation profile. The safety of
regional anesthesia in liver resections is based on appropriate timing of needle placement and
catheter removal and on the individual's skill in performing both the
puncture and the catheterization. In the absence of
liver failure or in cases of only moderate hepatic dysfunction, the risk of neurologic complications and spinal
hematomas does not appear greater than when an epidural is performed for routine abdominal or thoracic surgery. Various
anesthetic strategies have been adopted to prevent
bleeding during liver resection, such as fluid restriction,
diuretic administration, and
vasodilator drugs. Lowering central venous pressure (CVP) seems to play a prominent role in prevention of
bleeding since an elevated CVP may be associated with increased blood loss at various phases of liver resection. However, a low CVP may not be tolerated by all patients: intraoperative hemodynamic instability may, in fact, easily ensue because of the cardiovascular depressant effects of
anesthetics,
surgical blood losses, and manipulation of the inferior vena cava. We suggest combining intraoperative
epidural anesthesia with general (light)
anesthesia as a useful strategy to keep the CVP low during liver resection without
vasodilators or
diuretics.
Epidural anesthesia does not lead to changes in intravascular volume, but only promotes redistribution of blood, decreasing both venous return and portal vein pressure, thus contributing to reduced hepatic congestion and
surgical blood loss.