Prevalence of hypocalcaemia in term neonates and the clinical characteristics of the affected neonates admitted to the neonatal intensive care unit at the University Teaching Hospital

Abstract

Convulsions with concurrent hypocalcaemia are a common complication seen in very ill neonates at The University Teaching Hospital (UTH) Neonatal Intensive Care Unit (NICU) which admits close to 4000 neonates per year with various neonatal conditions. Convulsions in hypocalcaemic neonates have been found to be unamenable to anti-epileptic therapy thus leading to persistent convulsions which seem only to be controlled once calcium gluconate is administered to correct the hypocalcaemia. No studies in Zambia have been done to determine the burden of neonatal hypocalcaemia. Meanwhile, studies around the globe have shown prevalence levels of neonatal hypocalcaemia ranging from 17% to 39%. This study endeavored to determine the prevalence of hypocalcaemia in term neonates, the clinical characteristics of the affected neonates and to establish the proportion of neonates with seizures who also have hypocalcaemia. This was a cross sectional study with a sample size of 174 neonates (calculated using Epi info version 3.5.1 at power of 80%) who were enrolled to the study by simple random sampling methods out of 240 screened neonates. Data were analyzed using the statistical software package SPSS version 2. The relationship between study variables and outcome variable of interest (hypocalcaemia) was examined using logistic regression model which was considered at P < 0.20 significance. The prevalence of neonatal hypocalcaemia was found to be 26.4% (46/174) and 50% of these neonates presented with neurological disorders such as convulsions, hypertonia and hypotonia. Of the neonates who presented with convulsions in this study, 26.8% (19/71) were also found to have hypocalcaemia. However, there was no statistically significant association between convulsions and hypocalcaemia. The prevalence of hypocalcemia in term neonates admitted to NICU at UTH is high with half of the hypocalcaemic neonates manifesting neurological signs. Early identification and in turn treatment of hypocalcaemia in the neonates is paramount in achieving prompt interventional care of severely ill term neonates at increased risk of electrolyte imbalance. It is highly recommended to add to the essential list of investigations the measurement of serum calcium in the NICU.