Renal and Electrolyte Abnormalities in Heat Stroke during Hajj

Abstract

Background: Heat induced illnesses are variable from a mild heat exhaustion to a severe heat stroke and its systemic complications. Millions of pilgrims annually perform the Islamic obligatory mission of Hajj, are vulnerable to heat induced illnesses, especially when Hajj falls in the summer period. This is a retrospective study of the renal and electrolyte abnormalities in heat stroke patients during Hajj.
 Method: We selected randomly 472 patients out of 2044 patients diagnosed as heat stroke over 5 years from 1986-1991 for this study. The diagnosis of heat stroke was based on: 1) Rectal temperature > 40°C, 2) Hot dry skin and 3) Neurological deficit presenting as delirium, coma with or without convulsions. The renal function and electrolytes of all these patients were obtained.
 Results: All the 472 patients revealed significant electrolyte abnormalities: hypophasphatemia 98% (P + 0.55 ± 0.05 mmol/L), hyponatremia Na+ 70% (128 + 1 mmol/L), hypocalcemia 70% (Ca + 2.01 ± 0.02 mmol/L), hypokalemia 32% (K+3.3 ± 01 mmol/L), and hypomagnesaemia (Mg 0.06 ± 0.01 mmol/L) in 30%. Metabolic acidosis and compensatory respiratory alkalosis was seen in most patients. Acute renal failure that required dialysis developed in 180 (8.8%) patients. In 100 patients, the most common cause was Rhabdomyolysis (68%). The rest had ischemic acute tubular necrosis (32%) with a mortality of 15% compared to 20% in all the 472 patients. The risk mortality was higher in patients with a temperature of 42°C, comatose at presentation and older than 50 years.
 Conclusion: During Hajj, electrolyte abnormalities in heat stroke were found to be fairly common. Acute renal failure was mainly due to Rhabdomyolysis, which carry better prognosis compared to other causes of acute tubular necrosis.