INDEPENDENT RISK FACTORS FOR HOSPITAL-ACQUIRED HYPONATREMIA IN PEDIATRIC INTENSIVE CARE: A CASE-CONTROL STUDY

Background: With regard to electrolyte disorders, hospital-acquired hyponatremia (HAH) is one of the commonest seen in the inpatient environment and is associated with high morbidity and mortality risk related to the neurological effects. The large size ratio in the brain/IV volume in infants is associated with a higher risk for hyponatremic encephalopathy. Although of clinical importance, determinants of HAH in pediatric intensive care unit (PICU) are only partially documented in the setting of Pakistan. Objective: This is an observational study to observe the various independent risk-factors associated with the etiology of Hyponatremia in children who presented with it in Pediatric Intensive Care Unit of Children's Hospital&Institute of Child Health, Multan. Study Design: Type of Study: Measurement – Case control study. Setting: Children's Hospital&Institute of Child Health, Multan, Pakistan - Department: Pediatric. Duration: After institutional ethical approval: 6 months (from 18th April 2024 till 18th October 2024). Methodology:  In order to sample controls consecutively, children with hyperammonemic hypernatremic (262,1 month – 12 year, serum sodium < 135mEq/l during PICU stay) and isonatremic (131 isonatremic serum sodium 135 – 144 mEq/l during PICU stay) were sampled. Demographics, clinical and treatment data were gathered. ADH stimulating drugs (diuretics or antiepileptics), disease category, IV fluid used was hypotonic vs isotonic and last 4 weeks of stays were analysed for the risk factors. Stratified analyses by weight class, gender and age group was conducted and odds ratios (OR) with 95% confidence interval (CI) computed. Results: Median 4 (IQR 5.5) months when children enrolled, 63.4% male. Chest disorders (pulmonary) was the most prevalent admitting diagnosis (32.8%). The prevalence of each of the variables listed (hypotonic fluid use, ADH-stimulating drug use, and recent hospitalization) was significantly more common in cases than in controls (all p<0.001), respectively. Cases had 9.2-fold greater odds for having been exposed to hypotonic fluids in the three months prior to the survey (95% CI: 4.3–19.7), 6.2-fold greater odds for having been exposed to the use of an ADH stimulating drug in the three months prior to the survey (95% CI: 2.3–16.8), and 5.0-fold greater odds for being hospitalised in the last four weeks (95% CI: 2.1–11.9) prior to the survey. Disease category was non-statistically significant when adjusted for model.Disease category was not an independent predictor. The three risk factors were all statistically significantly different from each other in all age groups, genders and weight categories. Conclusion: Four risk factors that can be actively modified and occur in critically ill children, namely, administration of hypotonic IV fluid, pharmacotherapy that stimulates ADH secretion, and recent prior hospitalization, are independent and clinically actionable risk factors for HAH in critically ill children. These are unadjusted bivariate associations, and analysis using multivariate logistic regression with adjusted odds ratios was not conducted and is recommended to completely demonstrate independence. There is a great need for a multiprofessional prevention approach focusing on isotonic fluid protocols, greater care with the use of ADH-stimulating drugs and improved tracking of children recently hospitalized. Randomised controlled trials are suggested to test the effect of such interventions in the future.