The following are common electrolyte changes seen during heat stroke:
Dehydration leads to raised urea and creatinine with haemoconcentration. Excessive diaphoresis leads to low levels of Na, Mg, K, early in the illness. Hypokalaemia decreases sweat secretion and therefore exacerbates the condition.
Rhabdomyolysiss, secondary to tissue damage related to cell temperatures greater than 41 degrees celsius, results in hyperkalaemia, hypocalcaemia and renal failure may occur.
Metabolic acidosis and respiratory alkalosis common. Hyperthermia alone can cause primary hyperventilation and respiratory alkalosis, while hypoperfusion, tissue hypoxia, and anaerobic metabolism may lead to lactic acidosis with respiratory compensation.