Question 19.2

A 22-year-old male is brought into the Emergency Department with a decreased conscious state with a history of having been missing for over twenty-four hours. Results of his investigations are given below:

Parameter	Patient Value	Adult Normal Range
Sodium	149 mmol/L*	135 - 145
Potassium	6.0 mmol/L*	3.5 - 5.0
Chloride	114 mmol/L*	95 - 105
Bicarbonate	19.0 mmol/L*	22.0 - 26.0
Creatinine	210 urnoffL*	45 - 90
Urea	10.1 mmol/L*	3.0 - 8.0
Calcium	1.75 mmol/L*	2.10 - 2.60
Phosphate	2.29 mmol/L*	0.80 - 1.5
Magnesium	1.42 mmol/L*	0.70- 1.30
Albumin	21 a/L*	35 - 50
Alkaline phosphatase (ALP	62 IWI-	< 120
Gamma-glutamvl transferase (GCT)	22 IWI-	< 50
Alanine aminotransferase (ALT)	424 IU/L*	< 55
Aspartate aminotransferase (AST)	1679 IU/L*	< 50
Total bilirubin	12 urnol/L	< 19
T Protein	38 a/L*	60 - 82
Creatinine Kinase	10315 ICJ/L*	< 175

a) List five possible underlying causes that could lead to the abnormalities seen. (30% marks)

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College answer

Crush/pressure injury
Drug/Toxins
Hyperthermia
Prolonged status
Inflammatory myopathies
Infective – viral, bacterial myositis
Neuroleptic malignant syndrome

Discussion

So; the abnormalities seen are:

Hypernatremia (trivial)
Hyperkalemia
Hyperchloraemia
Acidosis
Anion gap 22 (delta ratio = 2.0)
High creatinine and urea
Low calcium
High phosphate
High magnesium
High AST but otherwise trivial LFT derangement
Massive CK elevation

Thus, this is probably some sort of rhabodmyolysis. The anion gap can be interpreted as lactate. In generral the features expected with rhabodomyolysis are an elevated CK, AST, LDH, urinary myoglobin, renal dysfunction and electrolyte abnormalities (particularly hyperkalemia, hypocalcemia, hyperphosphataemia, hyperuricemia, lactic acidosis). DIC may also be present.

Five possible causes of this are asked for. Numerous causes of rhabdomyolysis are listed in the appropriate chapter; of these, the following are the most relevant to the presentation (young man, missing for a day, found obtunded):

Alcohol intoxication
Recreational drugs (eg. MDMA)
Serotonin syndrome or neuroleptic malignant syndrome
Seizures
Head trauma with prolonged prostration, +/- compartment syndrome
Heat stroke

References

Bosch, Xavier, Esteban Poch, and Josep M. Grau. "Rhabdomyolysis and acute kidney injury." New England Journal of Medicine 361.1 (2009): 62-72.

Shapiro, Mark L., Anthony Baldea, and Fred A. Luchette. "Rhabdomyolysis in the intensive care unit." Journal of intensive care medicine 27.6 (2012): 335-342.

Hohenegger, Martin. "Drug induced rhabdomyolysis." Current opinion in pharmacology 12.3 (2012): 335-339.

Allison, Ronald C., and D. Lawrence Bedsole. "The other medical causes of rhabdomyolysis." The American journal of the medical sciences 326.2 (2003): 79-88.

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