These are the biochemical results taken from a 48-year-old male, 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 Adult Range
Sodium 126 mmol/L* 138 – 145
Potassium 3.5 mmol/L 3.5 – 5.0
Creatinine 250 μmol/L* 40 – 100
Urea 7.0 mmol/L 3.1 – 7.5
Bilirubin (total) 509 μmol/L * 2.0 – 22.0
Protein (total) 40 g/L* 65 – 85
Albumin 20 g/L* 38 – 48
Alkaline phosphatase (ALP) 153 IU/L* 40 – 100
Gamma glutamyl transferase (GGT) 459 IU/L* 0 – 50
Alanine aminotransferase (ALT) 336 IU/L* 0 – 45
Creatine kinase (CK) 400 IU/L* 30 – 180
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) Comment, with explanation, on each of the biochemical abnormalities.

b) List three possible causes of his altered conscious state.

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College Answer

a) Comment, with explanation, on each of 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:creatinine ratio suggests
that GI bleed and/or dehydration are unlikely

b) List three possible causes of his altered conscious state.

  • Alcohol intoxication
  • Hepatic encephalopathy
  • Drug ingestion
  • Sepsis
  • Intracranial bleed
  • Wernickes encephalopathy

Discussion

This question is nearly identical to Question 29.2 from the second paper of 2011. The answer to that question is also duplicated here, to simplify revision

The following is a list of biochemical abnormalities and plausible explanations for them:

  • 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.
  • Features of synthetic liver failure are present:
    • Ammonia is elevated.
    • Albumin is low.
    • Total protein is low.
    • Bilirubin is high
  • 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.
 

The college asks for three possible causes of unconsciousness in this comatose drunk. Three only. The most relevant ones would have to be

  • Hepatic encephalopathy
  • Alcohol intoxication
  • Sepsis

A possible list of differentials would have to also include the following:

  • V- Stroke
  • I- Septic encephalopathy
  • N- Seizures
  • D- Drug intoxication
  • I -
  • C-
  • A-
  • T- Intracerebral bleed, GI bleed
  • E- hyponatremia, hypoglycaemia

References

References

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Limdi, J. K., and G. M. Hyde. "Evaluation of abnormal liver function tests." Postgraduate medical journal 79.932 (2003): 307-312.

Hoekstra, Lisette T., et al. "Physiological and biochemical basis of clinical liver function tests: a review." Annals of surgery 257.1 (2013): 27-36.

Giannini, Edoardo G., Roberto Testa, and Vincenzo Savarino. "Liver enzyme alteration: a guide for clinicians." Canadian medical association journal 172.3 (2005): 367-379.

Kim, W., et al. "Serum activity of alanine aminotransferase (ALT) as an indicator of health and disease." Hepatology 47.4 (2008): 1363-1370.

Pratt, Daniel S., and Marshall M. Kaplan. "Evaluation of abnormal liver-enzyme results in asymptomatic patients." New England Journal of Medicine 342.17 (2000): 1266-1271.

Whitfield, J. B. "Gamma glutamyl transferase." Critical reviews in clinical laboratory sciences 38.4 (2001): 263-355.

Balistreri, William F., et al. "Intrahepatic cholestasis: Summary of an American Association for the Study of Liver Diseases single‐topic conference." Hepatology 42.1 (2005): 222-235.

Assy, N., et al. "Diagnostic approach to patients with cholestatic jaundice." World journal of gastroenterology 5.3 (1999): 252-262.

Stellpflug, Samuel J. "Transaminitis: The Lab Test That Has Inflammation…." Journal of Medical Toxicology 7.3 (2011): 252-253.