#UncleBob has some thoughts about liver test interpretation. During today's @CPSolvers Virtual Morning Report, we had a robust discussion of the meaning of the liver tests. I hope this thread will be worth #5goodminutes
@MohitHarshMD @rabihmgeha @DxRxEdu
@MohitHarshMD @rabihmgeha @DxRxEdu
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Preface: Our Chair of Medicine during my residency was a hepatologist. We could not use the term LFT because most of the tests do not evaluate liver function. So I always use the term liver tests.
Preface: Our Chair of Medicine during my residency was a hepatologist. We could not use the term LFT because most of the tests do not evaluate liver function. So I always use the term liver tests.
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In general we can divide liver tests into 3 buckets: cellular destruction, obstruction and production.
Cellular destruction: AST & ALT, GGTP
Obstruction: ALP, Direct Bilirubin, GGTP
Production: albumin, INR
In general we can divide liver tests into 3 buckets: cellular destruction, obstruction and production.
Cellular destruction: AST & ALT, GGTP
Obstruction: ALP, Direct Bilirubin, GGTP
Production: albumin, INR
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Cellular destruction interpretation varies with the level of AST & ALT rise. We all know that mild (AST <300) elevation with > 2:1 ratio with ALT suggests EtOH. Levels in the 1000 range suggest hepatitis - viral vs drug effect vs autoimmune.
Cellular destruction interpretation varies with the level of AST & ALT rise. We all know that mild (AST <300) elevation with > 2:1 ratio with ALT suggests EtOH. Levels in the 1000 range suggest hepatitis - viral vs drug effect vs autoimmune.
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You can get significant elevations with shock (so called shock liver). Modest elevations can suggest chronic hepatitis or drug effect. More severe elevations are very concerning.
You can get significant elevations with shock (so called shock liver). Modest elevations can suggest chronic hepatitis or drug effect. More severe elevations are very concerning.
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Obstruction is the trickiest part of liver tests. Usually we get elevated ALP and Direct Bilirubin. But one cannot differentiate consistently between extrahepatic and intrahepatic obstruction.
Usually with significant hepatitis we get elevations of ALP/D Bili
Obstruction is the trickiest part of liver tests. Usually we get elevated ALP and Direct Bilirubin. But one cannot differentiate consistently between extrahepatic and intrahepatic obstruction.
Usually with significant hepatitis we get elevations of ALP/D Bili
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These elevations occur because with cellular destruction, we usually get swelling and therefore intrahepatic biliary obstruction.
In today's patient, we had very high AST & ALT and minimal ALP elevation, consistent with a hepatitis picture.
These elevations occur because with cellular destruction, we usually get swelling and therefore intrahepatic biliary obstruction.
In today's patient, we had very high AST & ALT and minimal ALP elevation, consistent with a hepatitis picture.
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Finally clinical cirrhosis usually presents with decreased albumin and increased INR. This combination suggests a decrease in functioning liver cells. This can occur with severe hepatitis (as in today's patient).
Finally clinical cirrhosis usually presents with decreased albumin and increased INR. This combination suggests a decrease in functioning liver cells. This can occur with severe hepatitis (as in today's patient).
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Cautions - there are many other causes of decreased albumin and increased INR. We should always consider those possibilities, especially when only 1 of the 2 is abnormal
AST & ALT can also be elevated with muscle destruction. If that is a consideration a CK can help.
Cautions - there are many other causes of decreased albumin and increased INR. We should always consider those possibilities, especially when only 1 of the 2 is abnormal
AST & ALT can also be elevated with muscle destruction. If that is a consideration a CK can help.
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I hope this rather crude thread helps some learners think about liver tests. Please make suggestions for expansions, improvements and things I omitted.
I hope this rather crude thread helps some learners think about liver tests. Please make suggestions for expansions, improvements and things I omitted.
