These are the biochemical results taken from a 48-year-old man, missing from an alcohol rehabilitation program and found in his home comatose by police three days from the time he was last seen.

Parameter

Patient Value

Normal Range

Sodium

126* mmol/l

138 – 145

Potassium

3.5 mmol/l

3.5 – 5.2

Creatinine

250*µmol/l

40– 100

Urea

7.0 mmol/l

3.1– 7.5

Bilirubin (total)

509*µmol/l

2–22

Protein (total)

40* g/l

65– 85

Albumin

20* g/l

38– 48

ALP

153* IU/l

40– 100

GGT

459* IU/l

0–50

ALT

336* IU/l

0 - 45

CK

400* IU/l

30– 180

Troponin

0.1 µg/l

0–0.3

Glucose

3.2* mmol/l

3.5– 4.6

Ammonia

342*µmol/l

0–50

Lactate

3.7* mmol/l

0.6– 2.4

a)  Given this presentation, list 3 possible causes of his altered conscious state?

b)  Interpret the biochemical abnormalities

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College Answer

a)  Given this presentation, list 3 possible causes of his altered conscious state?

Alcohol intoxication

Hepatic encephalopathy 
Drug ingestion 
GI bleed

Sepsis 
Intracranial bleed

b)  Interpret the biochemical abnormalities

Liver dysfunction as demonstrated by elevated enzymes, reduced albumin, hypoglycaemia with decompensation indicated by marked elevation of ammonia. Hyponatraemia in keeping with cirrhosis. Raised lactate as a result of liver dysfunction / alcoholic ketoacidosis / sepsis / thiamine deficiency Raised creatinine indicates renal dysfunction and urea may be apparently “normal” because of decreased hepatic dysfunction and possible nutritional deficiencies. Urea:creatine ratio suggests that GI bleed and/or dehydration are unlikely

 

Discussion

This question interrogates the candidate's ability to generate a list of differential causes for a decreased level of consciousness in a person with chronic liver disease.

a)

Ok, the college has given us an alcoholic and put 342 µmol/l of ammonia into him.

Thus one of the differentials would have to be hepatic encephalopathy.

Given the extent of the other liver function abnormalities, and of course the borderline BSL, one could surmise that hypoglycaemia is another valid differential.

Being a drunk, alcohol intoxication is not out of the question.

One might wish to use the VINDICATE acronym to come up with some differentials.

  • V- Stroke
  • I- Sepsis
  • N- Seizures; hepatic encephalopathy
  • D- Drug intoxication (including alcohol)
  • I -
  • C-
  • A-
  • T- Intracerebral bleed, GI bleed
  • E- hyponatremia, hypoglycaemia

Fortunately, the college only asks for three answers. Hepatic encephalopathy, alcohol intoxication and sepsis seem the most likely, given the bloods.

b)  Interpret the biochemical abnormalities

  • Sodium is low due to the hypervolemic hyponatremia of cirrhosis
  • Creatinine is high potentially due to dehydration or hepatorenal syndrome.
  • Urea is normal likely due to nutritional deficiency or failure of the urea cycle. (so its probably not a GI bleed)
  • The LFTs are deranged in keeeping with a history of chronic liver disease, featuring a degree of synthetic failure (albumin of only 20) and hypoglycaemia.
  • The CK is only slightly elevated, suggesting seziures were probably not taking place before the police arrived
  • The lactate is raised, and there could be numerous reasons for this - but its likely either increased production due to sepsis or thiamine deficiency, combined with a decreased hepatic clearance.

There is some good material out there on the biochemical abnormalities of chronic liver disease, and their interpretation.

References

References

Chung, Raymond T., David L. Jaffe, and Lawrence S. Friedman. "Complications of chronic liver disease." Critical care clinics 11.2 (1995): 431-463.

 

Heidelbaugh, Joel J., and Michael Bruderly. "Cirrhosis and chronic liver failure: part II. Complications and treatment." American family physician 74.5 (2006).