Approach to abnormal liver function tests Flashcards
What part of an LFT measures the Liver’s ablity to detoxify metabolites and transport organic anions into bile?
Serum bilirubin
What are the aminotransferases measured in a LFT?
Alanine Aminotransferase (ALT) Asparate Aminotransferase (AST)
What term describes an enzyme that catalyzes a type of reaction between an amino acid and an a-keto acid?
Aminotransferase
What is the process describing the abnormal retention of lipids within a cell?
Steatosis
What part of a LFT correlates with the degree of trunk fat?
ALT
What accompanying symptoms should be evaluated in the patient with abnormal LFTs?
Jaundice Arthralgias Myalgias Rash Anorexia Weight loss Abdominal pain Fever Prurits Change is urine and stool
In the patient with abnormal LFTs, what might a history of arthralgias and myalgias predating jaundice indicate?
viral or drug-related hepatitis
In the patient with abnormal LFTs, what might jaundice associated with sudden onset of severe right upper quadrant pain and shaking chills suggest?
Choledocholithiasis and ascending cholangitis
What parenteral exposures should a patient be questioned about with abnormal LFTs?
Transfusion
IV and intranasal drug use
Tattoos
Sexual activity
What term describes the appearance of distended and engorged paraumbilical veins, which are seen radiating from the umbilicus across the abdomen to join systemic veins?
Caput Medusae
What are some of the stigmata of chronic liver disease?
Spider nevi
Palmar erthema
Gynecomastia
Caput medusae
What are the two broad categories that abnormal LFTs can be divided into?
Patterns predominantly reflecting hepatocellular injury
Patterns predominantly reflecting cholestasis
What term describes a condition where bile cannot flow from the liver to the duodenum?
Cholestasis
A Pt with hepatocellular injury usually has a disproportionate elevation in what aspect of the LFT?
Elevation in aminotransferases when compared to alakaline phosphatase
What might a low serum albumin suggest?
chronic hepatocelluar process such as cirrhosis or cancer
What is the first step when evaluating a patient with mild chronic elevation in serum aminotransferases?
Identify medications/supplements that can cause elevation
Assess alcohol use
Test for viral Hep B, Hep C hemochromatosis and fatty liver
What condition causes your body to absorb too much iron from the food you eat?
Hemochromatosis
What are common medications that cause elevation in aminotransferases?
NSAIDs, antibiotics, statins, antiepileptic drugs, antituberculous drugs.
What aminotransferase ratio supports the diagnosis of alcohol abuse?
AST to ALT ratio of 2:1
What enzyme is increased with early cholestasis?
Alkaline phosphatase
What other conditions/disorders can cause elevated Alkaline phosphatase other than choletasis?
Bone Disease
Intestinal obstruction
Pregnancy
What is a common hereditary disorder that causes impaired conjugation of bilirubin?
Gilbert’s Syndrome
What are some causes of decreased serum albumin?
Decreased liver production
Increased renal/GI loss (nephrotic syndrome, protein losing enteropathy in inflammatory bowel disease)
Protein malnutrition
What aminotransferases is more specific to the liver?
ALT
What type of bilirubin can be excreted by the kidney?
Conjugated/direct bilirubin
What might you suspect in a Pt with bilirubinurea?
cholestasis of some kind because only conjugated/direct bilirubin can be excreted by the kidney
What test can you perform to confirm that an elevated Alkaline Phosphatase is a result of cholestasis?
Gamma-Glutamyl Transferas (GGT)
What might you suspect if a Pt’s Direct Bilirubin made up over 50% of their total bilirubin?
Some sort of obstruction of the intra/extrahepatic ducts
