N Shrilakshmi, CC Deepu, Chittin N Swamy
Introduction: Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) is a frequent cause of hospital admission, and early identification of patients likely to have prolonged in-patient stay is clinically useful. Red Cell Distribution Width (RDW) and serum electrolyte disturbances are routinely available at admission, but their combined relationship with length of hospital stay is not consistently described. Aim: To assess admission RDW and serum electrolyte levels in patients admitted with AECOPD and to examine their association with length of hospital stay. Materials and Methods: This hospital-based prospective observational study was conducted in the Department of Respiratory Medicine, Adichunchanagiri Institute of Medical Sciences, BG Nagara, Karnataka, India, over three months from June 2025 to August 2025. A total of 50 consecutive patients aged 40 years or older admitted with AECOPD were analysed. RDW and serum electrolyte levels were measured at admission, and length of hospital stay was calculated from admission to discharge. Correlation analysis and multivariate linear regression were performed using IBM Statistical Package for Social Sciences (SPSS), version 30.0. A p-value<0.05 was considered statistically significant. Results: The mean age was 65.4±8.2 years, and the mean length of hospital stay was 10.6±2.8 days. Elevated RDW (>14.3%) was present in 41 (82%) patients, while hyponatraemia, hypokalaemia, hypocalcaemia, and hypomagnesaemia were observed in 38 (76%), 32 (64%), 29 (58%), and 18 (36%) patients, respectively. RDW showed a significant positive correlation with length of stay (r=+0.47, p=0.001). Serum sodium (r=-0.39, p=0.005) and potassium (r=-0.32, p=0.028) showed significant inverse correlations. In multivariate analysis, RDW (beta=+0.42, p=0.001), serum sodium (beta=-0.32, p=0.008), and serum potassium (beta=-0.25, p=0.038) remained independent predictors of length of hospital stay. Conclusion: Higher RDW and lower serum sodium and potassium at admission were independently associated with longer length of hospital stay among patients admitted with AECOPD. These routinely available admission parameters may support early risk stratification and inpatient management planning.