Pneumonia represents an acute respiratory infection seen in the lungs depicted by inflammation of the alveoli along with them getting filled with fluid and pus resulting in the painful breathing, respiratory distress, and impaired oxygen exchange. Its etiology can be attributed to various pathogens including fungi, bacteria, and viruses. CAP (Community-acquired pneumonia) is a condition defined as an acute infection of the lung parenchyma in a previously healthy child, acquired outside of the hospital settings, and not hospitalised within 14 days before onset of symptoms. Following the WHO (World Health Organisation), there have been significant deaths in child subjects aged <5 years from pneumonia that accounts for 14% of the deaths occurring under 5 years and 22% deaths in age range of 1-5 years considering the data of 2019.¹

The deaths occurring due to pneumonia are considerably higher in subjects residing in sub-Saharan Africa and Southern Asia. Concerning Indian context, pneumonia is a major cause of mortality that affect children most commonly. Following the data by UNICEF from the year 2018, India had a death rate of under 5-year children as 39.4 for every 1000 live births. Previous literature data also reports that a large number of under 5-year children die in India owing to pneumonia as every hour 20 death of children from pneumonia in India.²

Hyponatremia is a commonly seen associated electrolyte anomaly in child subjects with comm unity acquired pneumonia and is defined as serum sodium level of less than 135 mEq/dL. Majority of the child subjects that have hyponatremia need intravenous fluid management as the risk of aspiration, fatigue, and breathlessness usually limit needed oral intake of the fluids. This further result in acute hyponatremia and hemodilution that cause a sharp fluid shift to the brain cells causing cerebral edema. Association of hyponatremia and pneumonia was described first by Stormont and Waterhouse in the year 1962. Previous literature data has reported a high hyponatremia prevalence in community-acquired pneumonia and associated it with severity of the disease and increased mortality rate.³

Previous literature data also suggest that hyponatremia in community acquired pneumonia result in longer duration of hospital stay and double the complications and results in 4-fold increase in mortality compared to subjects with CAP and normal sodium levels warranting the probing of the issue.⁴ Hence, the present study was aimed to assess the association of hyponatremia with severity of illness, its course, duration of hospital stay, and outcomes in children aged two months to five years with community-acquired pneumonia.

The present descriptive observational study was aimed to assess the association of hyponatremia with severity of illness, its course, duration of hospital stay, and outcomes in children aged two months to five years with community-acquired pneumonia. The study was done at Department of Paediatrics, Gian Sagar Hospital & Medical College, Jhansla, Punjab. Verbal and written informed consent were taken from all the subjects before study participation.

The study assessed 212 subjects that visited the Institute with community-acquired pneumonia that presented to the Institute with community acquired pneumonia within the defined study period and were admitted to PICU (pediatric intensive care unit) of the institute and were diagnosed following the criteria by WHO. The inclusion criteria for the study were subjects aged 2 months to 5 years and had either severe or very severe pneumonia. The exclusion criteria for the study were subjects with severe acute malnutrition, aspiration pneumonia, pneumonia due to nosocomial infection, children on medication that can cause electrolyte disturbances, e.g., diuretics, anticonvulsants, CNS infections and malignancies, respiratory morbidity, pre-existing cardiac disease, known renal disease, and acute gastroenteritis.

After final inclusion of the study subjects, detailed history was recorded on a preformed structured proforma followed by comprehensive clinical examination in all child subjects that visited with pneumonia. Pneumonia and severe pneumonia were defined following the guidelines by WHO. At the admission, 2 ml blood was collected for assessing sodium levels from all the subjects under strict aseptic condition before initiation of antibiotics or intravenous fluids. Also, CRP (C-reactive protein) and TLC (Total Leucocyte Count) were analyzed in all the subjects.

Lung infiltrations were identified using the chest X-ray and subjects were followed for length of stay in the hospital, requirement of ventilation, and outcomes in terms of discharge or death for all the subjects. All subjects included for the study were managed following the standard protocol of the Institute.

The data gathered were statistically analyzed using chi-square test, Fisher’s exact test, Mann Whitney U test, and SPSS (Statistical Package for the Social Sciences) software version 24.0 (IBM Corp., Armonk. NY, USA) using ANOVA, chi-square test, and student's t-test. The significance level was considered at a p-value of <0.05.

The present descriptive observational study was aimed to assess the association of hyponatremia with severity of illness, its course, duration of hospital stay, and outcomes in children aged two months to five years with community-acquired pneumonia. The study assessed 212 subjects that visited the Institute with community-acquired pneumonia that presented to the Institute with community acquired pneumonia within the defined study period and were admitted to PICU. In all subjects aged 2-5 years, severity of illness, its course, duration of hospital stay, and outcomes were correlated with the anemia and results were formed.

It was seen that for demographic and disease data of study subjects at baseline, there were 16% (n=34) subjects aged ≤12 years and 84% (n=178) subjects aged >12 years. The danger signs seen were chest indrawing and fast breathing as seen in 58% (n=124) and 100% (n=212) subjects. Lung infiltration on chest X-ray was seen in 51% (n=108) subjects. Mean TLC count was 12116.6±3454.6. CRP levels were ≤10mg/dl and >10 mg/dl in 18% (n=38) and 82% (n=174) study subjects. Severity of hyponatremia was mild, moderate, and severe in 73% (n=66), 11% (n=10), and 16% (n=14) study subjects respectively. Ventilation needed was non-invasive and mechanical in 12% (n=26) and 4.7% (n=10) study subjects respectively (Table 1).

The study results showed that concerning comparison of various disease variable in study subjects with pneumonia and with and without hyponatremia, for severity, in pneumonia, hyponatremia was seen in 50% (n=56) and in severe pneumonia in 44.4% (n=40) subjects showing statistical significance with p=0.000. Hyponatremia was significantly higher in subjects with >7 days of hospital stay compared to subjects with hospital stay of ≤7 days with p=0.03. Also, higher incidence of hyponatremia was seen in subjects that died compared to subjects that were discharged following treatment with p=0.01 (Table 2).

On assessing the association between severity of pneumonia and severity of hyponatremia in study subjects, hyponatremia severity was mid, moderate, and severe in 67% (n=44), 40% (n=4), and 14% (n=2) subjects with pneumonia. Hyponatremia severity was mid, moderate, and severe in 33.3% (n=22), 60% (n=6), and 86% (n=12) subjects in severe pneumonia cases. Hyponatremia severity was mid, moderate, and severe in 66, 10, and 14 subjects respectively. The severity was significantly higher in severe pneumonia subjects for mild, moderate, and severe hyponatremia compared to subjects with pneumonia with p=0.02 (Table 3).

Table 1: Demographic and disease data of study subjects at baseline

Table 2: Comparison of various disease variable in study subjects with pneumonia and with and without hyponatremia

Table 3: Association between severity of pneumonia and severity of hyponatremia in study subjects

The present study assessed 212 subjects that visited the Institute with community-acquired pneumonia that presented to the Institute with community acquired pneumonia within the defined study period and were admitted to PICU. In all subjects aged 2-5 years, severity of illness, its course, duration of hospital stay, and outcomes were correlated with the anemia and results were formed. This was consistent with the previous studies of Roy A et al⁵ in 2025 and Pande V et al⁶ in 2024 where authors adopted study design similar to the present study as in the present study.

The study results showed that for demographic and disease data of study subjects at baseline, there were 16% (n=34) subjects aged ≤12 years and 84% (n=178) subjects aged >12 years. The danger signs seen were chest indrawing and fast breathing as seen in 58% (n=124) and 100% (n=212) subjects. Lung infiltration on chest X-ray was seen in 51% (n=108) subjects. Mean TLC count was 12116.6±3454.6. CRP levels were ≤10mg/dl and >10 mg/dl in 18% (n=38) and 82% (n=174) study subjects. Severity of hyponatremia was mild, moderate, and severe in 73% (n=66), 11% (n=10), and 16% (n=14) study subjects respectively. Ventilation needed was non-invasive and mechanical in 12% (n=26) and 4.7% (n=10) study subjects respectively. These findings were in agreement with the results of Karki L et al⁷ in 2016 and Hausman-Kedem M et al⁸ in 2018 where authors assessed subjects with demographic and disease data comparable to present study in subjects with CAP.

It was seen that concerning comparison of various disease variable in study subjects with pneumonia and with and without hyponatremia, for severity, in pneumonia, hyponatremia was seen in 50% (n=56) and in severe pneumonia in 44.4% (n=40) subjects showing statistical significance with p=0.000. Hyponatremia was significantly higher in subjects with >7 days of hospital stay compared to subjects with hospital stay of ≤7 days with p=0.03. Also, higher incidence of hyponatremia was seen in subjects that died compared to subjects that were discharged following treatment with p=0.01. These results were consistent with the findings of Sakellaropoulou A et al⁹ in 2010 and Sakellaropoulou A et al¹⁰ in 2019 where results comparable to the present study were also reported by the authors in their studies.

Concerning the association between severity of pneumonia and severity of hyponatremia in study subjects, hyponatremia severity was mid, moderate, and severe in 67% (n=44), 40% (n=4), and 14% (n=2) subjects with pneumonia. Hyponatremia severity was mid, moderate, and severe in 33.3% (n=22), 60% (n=6), and 86% (n=12) subjects in severe pneumonia cases. Hyponatremia severity was mid, moderate, and severe in 66, 10, and 14 subjects respectively. The severity was significantly higher in severe pneumonia subjects for mild, moderate, and severe hyponatremia compared to subjects with pneumonia with p=0.02. These findings were in line with the results of Awasthi S et al¹¹ in 2022 and Rabha J et al¹² in 2024 where results reported by the authors for association between severity of pneumonia and severity of hyponatremia were comparable to the results of the present study.

The present study, considering its limitations, concludes that hyponatremia is commonly seen in child subjects with community acquired pneumonia and there is a significant association in hyponatremia with the severity of pneumonia, high mortality in children with community acquired pneumonia, prolonged hospital stays, increased need for ventilation, and association of severe hyponatremia with severe pneumonia.

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