Hypo- and hypermagnesemia in an Indian Pediatric Intensive Care Unit.

Data on magnesium disturbances in critically ill children admitted to a Paediatric Intensive Care Unit (PICU) are scarce, especially from developing countries. We have studied occurrence and incidence of hypo- and hypermagnesaemia in children admitted to a PICU and the correlation between such disturbances and the outcome of illness. A total of 100 children (68 boys, 32 girls) aged 6 months to 12 years (mean +/- SD 4.9 + 3.5 years) admitted consecutively to a PICU were studied. At admission and on every alternate day venous blood was obtained for the estimation of serum and RBC-magnesium, serum calcium, sodium, and potassium, and arterial blood for ionized calcium and pH. This was done after ethical approval and informed consent. Hypomagnesaemia and hypermagnesaemia occurred in 60 per cent and 4 per cent of patients, respectively. The incidence of hypomagnesaemia was 30.1, and hypermagnesaemia was two episodes per 100 patient days. The incidence of low RBC-Mg was 17.3 episodes per 100 patient days. Hypomagnesaemia was most common in patients with raised intracranial pressure (63 episodes per 100 patients days). Mortality was nine-fold higher in hypomagnesaemic (30 per cent, 19 of 63) compared with normomagnaesemic (3.3 per cent, one of 30) patients. If Mg and Ca both were low, the mortality rate was 33 per cent (15 of 45 patients) in contrast to nil if both were normal (p < 0.05). We conclude that hypomagnesaemia and low RBC-Mg are a common occurrence in PICU patients and are associated with higher mortality.