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)
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.