Clinical Cases

Severe Heat Exhaustion & Impending Heat Stroke with Exceptionally High Serum CPK

We present the case of one patient who demonstrated extremely high CPK levels and heat exhaustion symptoms despite limited heat exposure, demonstrating the importance of hematuria as an indicator of heat stroke risk.

By Dr Jobin Benjamin

Published on :

INTRODUCTION

Heat exhaustion is frequent in the summer months and may progress to heat stroke, which poses a threat to life. The enzyme Creatine Phosphokinase (CPK) is prognostic of heat stroke as its presence in the blood indicates tissue damage. High serum CPK typically occurs with physical exertion, particularly under high heat conditions, and is associated with rhabdomyolysis and hypokalemia [1], however this is not always the case. We present the case of one patient who demonstrated extremely high CPK levels and heat exhaustion symptoms despite limited heat exposure, demonstrating the importance of hematuria as an indicator of heat stroke risk.

Case Summary

The patient, a 33 year old male ship worker, arrived at Aster Hospital Qatar with unexplained hematuria along with generalized weakness, mild giddiness and disorientation which had lasted for 3 days. He was referred from the ship by the medical specialist due to macroscopic hematuria, with a view to evaluate him for renal calculi or a urinary tract infection.

On examination, the patient appeared normal, and was conscious and orientated. However, after clinical examination and recording the patient history, he was found to have heat exhaustion as a result of working in the ship. He was found to be poorly hydrated and to have a very grossly elevated initial CPK level of more than 72000u/l (normal range = 40-210u/l). Ironically, all other values of LDH and renal function liver enzymes were within normal limits.

The patient was not in contact with direct heat, but had been working within the ship. The ambient temperature was not specified. He was not doing any strenuous work and was only involved in mild to moderate physical activity. He had no history of similar episodes, cardiac disorders or lifestyle disorders. An abdominal ultrasound was normal in appearance. Within 24 hrs the CPK had fallen below 50000u/l, and after 3 days to 2770u/l. The patient recovered following IV treatment and was discharged.

DISCUSSION

The CPK enzyme level at admission was very high; levels of 75000u/l + are very rare to find in patients with this type of presentation. Despite the patient’s otherwise normal indicators, with his admission CPK value, it is highly surprising that he did not go on to develop heat stroke. This study indicates the importance of conducting routine urinary examinations to detect early chances of heat exhaustion or heat stroke in cases of macroscopic or microscopic hema- turia. In this case, the diagnosis was completely different to that expected based on the presentation.

References

1. Alzeer AH, El-Hazmi MAF, Warsy AS, Ansari ZA, Yrkendi MS. Serum enzymes in heat stroke: prognostic implication. Clin Chem.1997;43(7):1182-1187.

Aster Medical Journal
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