Correction rates in severe hyponatremia, a retrospective analytic study: Implications in a cancer patient population

Background: Hyponatremia is a common electrolyte disturbance among hospitalized cancer patients and is associated with increased morbidity and mortality. Optimal correction rates for severe hyponatremia remain debated, particularly in oncology populations where comorbidities and treatment-related factors complicate management. Methods: We conducted a retrospective cohort study of adult cancer patients admitted to Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC), Lahore, Pakistan, between January 2011 and March 2023 with severe hyponatremia (serum sodium ⩽120 mEq/L). Patients were categorized based on 24-h sodium correction rates: <6 mEq/L, 6–10 mEq/L, and >10 mEq/L. Outcomes included in-hospital mortality, 30-day mortality, and length of stay. Multivariable logistic regression models were used to assess associations between correction rates and mortality. Results: Among 939 patients, 45.5% had correction <6 mEq/L/24 h, 24.7% had 6–10 mEq/L/24 h, and 29.8% had >10 mEq/L/24 h. In-hospital and 30-day mortality were significantly higher in the slow correction group compared with rapid correctors (in-hospital: 54.1% vs 20.4%; p = 0.003; 30-day: 55.3% vs 20.6%; p < 0.001). On multivariable analysis, a correction >10 mEq/L/24 h was independently associated with lower in-hospital mortality (adjusted OR = 0.58; 95% CI: 0.36–0.92; p = 0.021). One case of osmotic demyelination was identified. Conclusions: In hospitalized cancer patients with severe hyponatremia, slow correction (<6 mEq/L/24 h) was associated with significantly higher mortality, whereas rapid correction (>10 mEq/L/24 h) was linked to improved survival without significant neurological complications. Prospective multicenter studies are warranted to investigate the associations between the different etiologies of hyponatremia and mortality.