Liver Transplant Flashcards
What is hepatopulmonary syndrome?
Hepatopulmonary syndrome is severe hypoxemia due to liver disease. The defining characteristics are the presence of portal hypertension, an increased alveolar-arterial oxygen gradient,
and intrapulmonary vasodilation. Patients may exhibit clubbing of the fingers, spider angiomata, arterial hypoxemia, and dyspnea that worsens when the patient moves from a recumbent to an upright position.
A patient with aortic stenosis, a patient with renal
failure and a patient with a mean PA pressure of 52
mmHg all present for liver transplant surgery. Which
patient cannot proceed with the surgery?
Renal failure is a common diagnosis in patients presenting for liver transplantation. Aortic stenosis has an associated increase in risk, but can often be treated preoperatively with valvuloplasty prior to surgery and then aortic valve replacement
may be undertaken after the transplant. Patients with portopulmonary hypertension have an extremely high perioperative mortality rate with liver transplant surgery. A mean PA pressure greater than 50 mmHg is considered an absolute contraindication to liver transplant.
Why is rapid-sequence induction indicated in all
patients presenting for liver transplant surgery?
End stage liver disease is associated with gastroparesis as well as increased intra-abdominal pressure due to ascites that places the patient at risk for aspiration of gastric contents.
A patient with hepatorenal syndrome is undergoing a liver transplant. Is dopamine a useful adjunct for the preservation of renal function in this patient?
No, dopamine does not improve renal function in patients undergoing liver transplant. Norepinephrine and the alpha1- agonist, midodrine have both been shown to improve renal function during liver transplant, however.
A patient with hepatorenal syndrome and severe
ascites is about to undergo a large-volume (> 5 L)
paracentesis. What can be done to prevent the
renal decompensation as a result of the removal of
such a large volume of abdominal fluid?
Albumin 6-8 grams per liter of ascites removed should be administered to help prevent renal decompensation.
What is the difference between type I and type II
hepatorenal syndrome?
Hepatorenal syndrome is renal dysfunction associated with hepatic disease. Type I is acute renal decompensation, exhibits a creatinine > 2.5 mg/dL and is often fatal. Type II hepatorenal
syndrome is chronic, exhibits a creatinine > 1.5 mg/dL, and a glomerular filtration rate < 40 mL/min.
What coagulation parameters are monitored and
how are they maintained in patients undergoing liver
transplant surgery?
Fresh frozen plasma is administered to maintain an INR 150 mg/dL.
What medications would you be prepared to
administration prior to the reperfusion of a newly
transplanted liver?
When the liver is about to be reperfused, you should anticipate the administration of bicarbonate and calcium chloride to counteract the effects of potassium on the heart.
In what phase of a liver transplant would you expect
to see the most hemodynamic instability?
The greatest hemodynamic changes are typically seen during the neohepatic period when the transplanted liver is reperfused. Reperfusion of the vena cava is usually well tolerated, but reperfusion of the portal vein is associated with a drop in the systemic vascular resistance that is even greater
than that seen with vena cava cross-clamp. Severe
bradycardia may also be seen, although it is becoming less common due to changes in the preservative solutions used.
What hemodynamic change would you expect to see when the anhepatic phase of a liver transplant is
initiated?
Hypotension usually ensues as the vena cava is cross-clamped due to a 50-60% reduction in venous return.
Hypotension usually ensues as the vena cava is cross-clamped due to a 50-60% reduction in venous return.
Typically, the vena cava is clamped above and below the liver and the portal vein and hepatic artery are clamped below the liver.
What are the three phases of liver transplant
surgery?
The dissection phase, in which the incision and access to the liver is obtained, the anhepatic phase, in which the liver is isolated from the circulation, and the neohepatic period in which
the new liver is reperfused.
Within the first hour of the neohepatic period, the
patient exhibits a decrease in cardiac output and anincrease in systemic vascular resistance. What does this change indicate?
A decrease in cardiac output and an increase in the SVR indicates that the graft is functioning correctly and the new liver is beginning to metabolize the vasoactive substances that
produce the characteristic low SVR and high cardiac output in patients with end stage liver disease. Other signs that the graft is functioning correctly include: calcium is no longer needed
even when large volumes of FFP are infused as the new liver is able to metabolize the citrate preservative and the base deficitnormalizes.
