FREQUENCY OF HOSPITAL-ACQUIRED HYPONATREMIA IN CHILDREN RECEIVING MAINTENANCE INTRAVENOUS FLUIDS AT A TERTIARY-CARE HOSPITAL IN KARACHI, PAKISTAN: A CROSS-SECTIONAL STUDY

Abstract

Background: Hospital-acquired hyponatremia (HAH) is a common and potentially preventable electrolyte abnormality in hospitalized children. It may lead to cerebral edema, seizures, encephalopathy, and death. Reported frequencies vary widely across settings, and contemporary Pakistani data remain limited.

Objective: To determine the frequency of HAH and its association with age, sex, place of admission, and type of maintenance intravenous fluid among children admitted to a tertiary-care hospital.

Methods: This cross-sectional study was conducted in the Department of Pediatrics, Dr. Ruth K.M. Pfau Civil Hospital, Karachi, Pakistan, from 30 December 2021 to 30 June 2022. Children aged >1 month to 14 years, admitted for >48 hours, with admission serum sodium >135 mEq/L and requiring maintenance intravenous fluids, were enrolled through non-probability consecutive sampling. Serum sodium was measured at admission and 48 hours later. HAH was defined as serum sodium <135 mEq/L at 48 hours in a child with normal sodium at admission. Data were analyzed using IBM SPSS version 23. Chi-square or Fisher’s exact tests were applied, and p<0.05 was considered statistically significant. Institutional approval and informed consent were obtained.

Results: Of 121 children, 42 (34.7%) developed HAH. The mean age was 3.4 ± 3.1 years; 68 (56.2%) were male and 53 (43.8%) were female. HAH was significantly more frequent among female children (45.3% vs. 26.5%; p=0.030) and among children receiving 0.45% dextrose saline (DS) compared with 0.9% DS (46.8% vs. 27.0%; p=0.026). No significant association was found with age <7 years (37.6% vs. 20.0%; p=0.130) or admission to the pediatric ward versus ICU (37.6% vs. 25.0%; p=0.210). Common diagnoses among HAH cases were gastrointestinal and infectious diseases (28.6% each), respiratory disease (21.4%), and malnutrition with sepsis (14.3%).

Conclusion: HAH occurred in approximately one-third of hospitalized children receiving maintenance intravenous fluids. Female sex and hypotonic fluid (0.45% DS) were significantly associated with HAH. These findings support careful maintenance-fluid selection and regular serum sodium monitoring. Larger multicenter studies with adjusted analyses are needed to confirm these associations.