Hyponatremia and Low Bicarbonate Affect Nearly 6 in 10 Adults Hospitalized with Enteric Fever: Study

Enteric fever, which is caused by Salmonella enterica serovars Typhi and Paratyphi, remains a critical public health challenge in developing nations like India, where the Surveillance for Enteric Fever in India (SEFI) reports incidences as high as 1,200 cases per 100,000 people; however, while previous research in Bangladesh and Nigeria has noted significant biochemical disturbances, contemporary data on the electrolyte profiles of Indian adults remained limited until Shubham Mishra and Sandeep Budhiraja from the Department of Internal Medicine at Max Super Specialty Hospital (MSSH), New Delhi, conducted the study to characterize these patterns and help clinicians anticipate potential complications.

Therefore, following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines, the retrospective observational study analyzed the baseline biochemical profiles of 128 adult patients hospitalized with laboratory-confirmed typhoid or paratyphoid fever between January 2023 and March 2024 at a tertiary care center serving urban and semiurban populations. The researchers utilized automated biochemistry analyzers to measure sodium and potassium through ion-selective electrode (ISE) technology, chloride via colorimetric methods, and bicarbonate through the modified Forrester enzymatic method, while excluding patients who lacked laboratory confirmation or complete electrolyte panels to ensure the accuracy of the primary prevalence and pattern endpoints.

Key Clinical Findings of the Study Include:

• Prevalent Hyponatremia: The investigation found that 58.6% of the 128 patients presented with hyponatremia, with a mean sodium level of 132.7 ± 6.2 millimoles per liter (mmol/L) compared to the standard reference range of 135–155 mmol/L.

• Bicarbonate Depletion: The analysis identified that 57.8% of patients had bicarbonate levels below the 22–32 mmol/L reference range, averaging 20.3 ± 4.7 mmol/L, which indicates a significant tendency toward metabolic acidosis.

• Preserved Potassium Balance: The research highlighted that potassium concentrations remained largely unaffected in the majority of the cohort, with 95.3% of patients displaying normal values and an overall mean of 4.3 ± 0.6 mmol/L.

• Stable Chloride Concentrations: The assessment demonstrated that 89.8% of participants maintained chloride levels within the normal clinical range of 98–108 mmol/L, with a reported mean of 101.1 ± 3.7 mmol/L.

• Gender-Independent Results: The investigation established that there were no statistically significant differences (p > 0.17) between male and female patients regarding mean electrolyte values or the overall distribution of these biochemical abnormalities.

The results suggest that hyponatremia and reduced bicarbonate are the most frequently encountered electrolyte disturbances in hospitalized adults with enteric fever, affecting nearly six out of ten individuals.

Thus, the study concludes clinicians should consider incorporating routine electrolyte monitoring for sodium and bicarbonate into the standard management protocols for hospitalized patients with enteric fever to facilitate early identification and supportive management of these common metabolic alterations.

While this study was limited by its single-center retrospective design and lack of longitudinal data on clinical outcomes or specific mechanisms like the syndrome of inappropriate antidiuretic hormone secretion (SIADH), there is a recognized need for future multicenter prospective investigations to further validate these biochemical patterns and their prognostic significance.

Reference

Mishra S, Budhiraja S. Alterations in Serum Electrolytes among Adults with Enteric Fever: A Retrospective Observational Study from a Tertiary Center in New Delhi. J Assoc Physicians India 2026;74(3):22–25.