Prevalence and Correlates of Hyponatremia in Critically Ill Elderly patients at the time of Admission, its impact on clinical course of ICU in a specialized geriatric facility in northern India

To assess the prevalence of hyponatremia in critically ill elderly patients on admission to acute care facility; its clinic-demographic correlates, impact on clinical course and outcome.MethodThe study was done at a centre for geriatric medicine palliative care hospital & hospice at its critical care unit at Lucknow between 2021-2022 for one year. A total of 267 subjects from the hospital records of non-COVID ICU admissions were analysed. Serum sodium levels < 135 mEq/L at admission was considered as hyponatremia. Demographic profile and comorbidity profile of the patients were also noted as per profroma. Severity of hyponatremia was assessed as mild (130-134.9 mEq/L), moderate (125-129.9 mEq/L) and severe (< 125 mEq/L) respectively. Total duration of ICU stay was noted as clinical course of illness and in-ICU mortality was noted as the final outcome. Data was analysed using SPSS 21.0 software. Chi-square, independent samples t-test and ANOVA were calculated.ResultsMean age of the patients was 72.65 & PLUSMN; 7.82 years (range 60-93 years), majority of them were men (56.2%). At admission, hyponatremia was seen in 36.3% (n = 97). Of this majority (n = 50; 51.5%) had mild, followed by moderate (n = 31; 32.0%) and severe (n = 16; 16.5%) hyponatremia. Mean duration of ICU stay was 8.65 & PLUSMN; 5.51 days (range 1-45 days). Mortality was seen in only 10 (3.7%) subjects. History of cardiovascular disease and higher mean number of comorbidities showed a significant association with at-admission hyponatremia. Mortality rate was significantly higher in hyponatremic (8.2%) as compared to non-hyponatremic patients (1.2%). Severity of hyponatremia showed a significant association with hypertension, cardiovascular disease, number of comorbidities, type of hyponatremia, but did not show a significant association with duration of ICU stay and mortality.ConclusionHospitalised critically ill elderly had a high prevalence of hyponatremia in just over 1/3(rd) subjects (36.3%) at the time of admission. Higher mortality and poor overall outcome were seen in those who also had hyponatremia irrespective of the index illness.