Can the measured pleth variability index (PVI) values predict clinical severity in patients presenting to the emergency department with copd exacerbation?

Aim: Chronic Obstructive Pulmonary Disease (COPD) is a chronic illness characterized by exacerbations, leading to high mortality and morbidity. COPD exacerbations frequently result in emergency department visits, complicating patient management in overcrowded settings. The Pleth Variability Index (PVI) calculates changes in the perfusion index (Pi) during at least one respiratory cycle, indirectly reflecting pulsus paradoxus. It is suggested that PVI is associated with the severity of acute attacks in obstructive airway diseases. This study aims to investigate the role of PVI in predicting the severity, clinical course, and prognosis of COPD exacerbations. Materials and Methods: This prospective study was conducted between May 2023 and May 2024 with patients over 18 years old who were known to have COPD and presented to the Emergency Department of Samsun University Samsun Training and Research Hospital with symptoms of COPD exacerbation. The PVI values measured from the fingertip at the time of admission and after treatment were compared in terms of the severity of COPD exacerbations, the need for hospitalization, and the development of mortality, according to current guidelines Results: A total of 131 patients were included in the study. The median triage PVI value of the patients was 42% (14-99). The median triage PVI value was 50% (31-99) for patients presenting with severe exacerbation, 36% (14-69) for those with moderate exacerbation, and 24% (14-45) for those with mild exacerbation, with a significant difference between the groups (p<0.001). The median post-treatment PVI value was 27% (8-68), which was significantly lower than the triage PVI value (p<0.001). A PVI value above 40% had a sensitivity of 86.44% and specificity of 75% for predicting severe exacerbation (AUC: 0.828; CI: 0.753-0.889; p<0.001). The median PVI value was 32% (14-71) for patients discharged from the emergency department and 47% (17-99) for those admitted to the hospital (p<0.001). A PVI value above 41% had a sensitivity of 62.89% and specificity of 85.29% for predicting hospitalization (AUC: 0.731; CI: 0.646-0.805). The median PVI value was 55% (30-99) for patients who died, compared to 38.5% (14-77) for those who survived (p<0.001). A PVI value above 40% had a sensitivity of 94.12% and specificity of 53.51% for predicting mortality (AUC: 0.774; CI: 0.692-0.842; p<0.001). Conclusion: The PVI value is a useful parameter for determining the severity of COPD exacerbations and for predicting the prognosis of the disease. Key words: COPD exacerbation, PVI, emergency department, prognosis