BMC Pulmonary Medicine, cilt.26, sa.1, 2026 (SCI-Expanded, Scopus)
Background: Early risk stratification in Chronic Obstructive Pulmonary Disease (COPD) exacerbations is essential for effective management. The Pleth Variability Index (PVI), a non-invasive parameter derived from photoplethysmographic waveforms, has been evaluated in various clinical settings; however, its relevance to COPD exacerbation severity in adults remains unclear. This study aimed to assess the association between admission PVI values and COPD exacerbation severity, hospital admission, and 30-day mortality. Methods: This prospective, single-center study was conducted in a tertiary hospital between September 2023 and September 2024 with ethics approval. Adults (≥ 18 years) with COPD exacerbation were included, while those with cardiac or other pulmonary conditions, or factors affecting PVI, were excluded. PVI was measured non-invasively at admission and 2 h post-treatment using the Masimo Root device. Clinical data, laboratory results, outcomes, and 30-day mortality were recorded. COPD exacerbation severity was classified according to the Global Initiative for Obstructive Lung Disease (GOLD), and patients were grouped by their outcomes. Analyses included Receiver operating characteristic (ROC) curves, correlation, and regression models. Results: Of 204 patients, 131 were included (mean age 70.6 ± 10.5; 77.1% male). Exacerbations were mild in 23 (17.6%), moderate in 49 (37.4%), and severe in 59 (45.0%). The median PVI was 42% at admission and 27% post-treatment (p < 0.001), with higher values observed in patients with more severe cases. 34 (25.9%) discharged, 38 (29.0%) admitted to ward, 59 (45.0%) to Intensive Care Unit (ICU), and 17 (13.0%) died. ICU and mortality groups had higher admission PVI. A baseline PVI > 40 predicted severe exacerbation (AUC = 0.828), ICU admission (AUC = 0.867), and mortality (AUC = 0.774). PVI correlated negatively with oxygen saturation and pH, positively with Partial Pressure of Carbon Dioxide (pCO₂), and was an independent predictor of ICU admission and 30-day mortality. Conclusion: PVI emerges as a valuable parameter in predicting exacerbation severity, hospital admission, and mortality in COPD exacerbations. With non-invasive and rapidly measurable advantages, PVI can be utilized as a complementary prognostic tool in triage and treatment processes in the emergency department.