Clinical implications of hypocalcemia in malaria

Total serum calcium levels were estimated in 60 adult patients with malaria to know the prevalence of hypocalcemia in different types of malaria and its clinical implications. As hypocalcemia is known to cause Q-Tc interval prolongation, electrocardiograms were obtained in all patients with low calcium levels. Twenty seven (45%) patients with malaria had hypocalcemia. Majority (88.24%) of the complicated malaria patients had hypocalcemia as against uncomplicated malaria (27.91%). Mean calcium levels were significantly lower in complicated malaria (7.4 +/- 0.98 mg/dl) when compared to uncomplicated malaria (8.4 +/- 0.44 mg/dl). There was an inverse relation between calcium levels and parasite load (P < 0.05). Significant correlation was also seen between the degree of hypocalcemia and Q-Tc prolongation (P < 0.01). Return of calcium levels to normal coincided with clinical recovery and parasite clearance. Three patients who had low calcium levels and prolonged Q-Tc died of hypotension, bradycardia and heart block after quinine therapy. The exact cause of hypocalcemia could not be ascertained but renal failure, hypomagnesemia and parathyroid failure could have been contributary. In conclusion, hypocalcemia is not uncommon in complicated malaria. It can be of prognostic value as it may indicate complicated malaria or heavy parasitemia and its return to normal may indicate clinical recovery and parasite clearance.