A Prospective, Observational Study of the Prognostic Value of Hematocrit in Patients with Severe Chronic Obstructive Pulmonary Disease Receiving Long-term Oxygen Therapy

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) having a major cause of morbidity or mortality worldwide. Hematocrit (HCT), a simple or inexpensive marker, provides prognostic information in severe COPD patients receiving long-term oxygen therapy (LTOT), yet Indian data are scarce. AIMS AND OBJECTIVES: To evaluate the prognostic value of HCT in patients with severe COPD on LTOT, assess its trend over time, and correlate HCT with spirometry and arterial blood gas (ABG) parameters. METHODOLOGY: Over 18 months, the Department of Respiratory Medicine at Shri Sathya Sai Medical College and Research Institute in Tamil Nadu carried out this prospective observational study. 100 and 11 patients with severe COPD on LTOT (≥18 h/day) were enrolled after ethical clearance (IEC No: 993/24) and written informed consent. Baseline demographic, clinical, spirometry, HCT, and ABG parameters were recorded and reassessed at 45 days and 3 months. Data were analyzed utilizing SPSS v29. Mean ± standard deviation was employed to express the continuous variables. Pearson correlation and paired t-test was utilized; P < 0.05 has been considered statistically significant. RESULTS: The mean age was 62.8 ± 8.1 years; 58.6% were males. Most participants had severe COPD (64.9%); mean disease duration was 7.4 ± 3.5 years, or mean LTOT duration was 18.6 ± 7.8 months. Baseline HCT was 42.3 ± 3.1%. It declined to 41.7 ± 2.8 at 45 days (P = 0.056) and 41.5 ± 3.0 at 3 months (P = 0.024). Forced vital capacity (FVC) showed a progressive decline from 2.0 ± 0.28 L at baseline to 1.8 ± 0.26 L at 45 days or 1.6 ± 0.29 L at 3 months (P < 0.001). In contrast, forced expiratory volume in 1 s (FEV1) increased from 0.7 ± 0.11 L at baseline to 0.8 ± 0.12 L at 45 days and 0.9 ± 0.14 L at 3 months (P < 0.001). The FEV1/FVC ratio also increased from 0.35 ± 0.19 at baseline to 0.44 ± 0.13 at 45 days or 0.46 ± 0.12 at 3 months (P < 0.001). Significant correlations have been observed among HCT or PaO2 (r = 0.32, P = 0.01) and among HCT and FEV1/FVC ratio (r = 0.29, P = 0.02). Lower baseline HCT was associated with increased hospitalization and mortality (P < 0.05). CONCLUSION: HCT is an independent prognostic marker in severe COPD patients on LTOT. Declining HCT over time may indicate poor outcomes, while higher values correlate with better oxygenation and lung function. Serial HCT measurement can be a cost-effective tool to risk-stratify and monitor patients in the resource-limited settings.