Today's case involved a middle-aged man with not much past medical history
besides hypertension. He presented secondary to abnormal laboratory
values including a bilirubin of nearly 400, and elevated transaminases into the
1000’s. He had ascites and imaging
evidence of chronic cirrhosis, as well as a portal vein
thrombus. He did, however, have normal
liver enzymes only a few weeks prior to his presentation suggesting this to be
an acute process.
There were multiple
valuable learning points today:
-Acute transaminase
elevation into the range of thousands has a limited differential diagnosis
which is worth remembering. This
includes viral hepatitis, autoimmune hepatitis, acute cholangitis/gallstone
obstruction, acute fatty liver of pregnancy, drug-induced heptatitis
(acetaminophen, not alcohol), portal
vein thrombosis, and ischemic hepatitis (shock
liver as it is so lovingly called).
-We spoke briefly
about the physical examination for ascites.
It is worth remembering that ankle
edema has a 93% sensitivity for ascites, meaning that ascites presence is
extremely unlikely if there is no ankle edema.
That said, if there is ankle edema, you need a specific test to rule in
ascites. The combination of flank
dullness, a positive shifting dullness, and a positive fluid wave can be
helpful in this case. Most of your
patients will receive abdominal ultrasounds anyways.
-We briefly discussed
hemolysis (the other cause of hyperbilirubinemia). The hemolytic
workup includes a CBC, blood film, LDH, haptoglobin, and bilirubin. To this I sometimes add a DAT or Coomb’s test
for autoimmune hemolytic anemia, and sometimes a fibrinogen level and/or
D-Dimer for consumptive coagulopathies like disseminated
intravascular coagulation.
-We talked about liver function which is frequently and
erroneously misinterpreted as transaminase
levels. The two are completely different
and occasionally unrelated. The liver’s function is to produce albumin,
coagulation factors (check INR/PTT), eliminate nitrogenous waste
(asterixis/encephalopathy), clear portal blood of toxins/nutrients (ascites and
thrombocytopenia from portal hypertension), and produce glucose in states of
starvation (hypoglycemia is a feature of advanced liver failure). Transaminase elevation can occur without
impairing these functions, and these functions can be quite impaired with mild
or no transaminase elevation.
For further reading,
I’m including a review of an approach to abnormal liver enzymes, and a review
and approach to thrombotic microangiopathy, as well as the JAMA Rational
Clinical Exam series article about ascites.
Further Reading:
Kaplowitz, N. (2004).
Drug-induced liver injury. Clinical Infectious Diseases, 38(Supplement
2), S44-S48.
Moake, J. L. (2002).
Thrombotic microangiopathies. New England Journal of Medicine, 347(8),
589-600.
Limdi, J. K., &
Hyde, G. M. (2003). Evaluation of abnormal liver function tests. Postgraduate
medical journal, 79(932), 307-312.
|
|
Chicago
|
|
Williams, J. W., &
Simel, D. L. (1992). Does This Patient Have Ascites?: How to Divine Fluid in
the Abdomen. Jama, 267(19), 2645-2648.
No comments:
Post a Comment