Patients with severe airway obstruction may exhibit pulsus paradoxus like physiology. The present study was performed as a pilot to see if Pleth Variability Index (PVI) may be used to quickly and noninvasively detect the degree of obstruction in patients with lung disease.
During evaluation of patients with lung disease in a small pulmonary practice pulse oximetry was performed using a Radical 7 pulse co-oximeter capable of deriving a PVI by analyzing the oximetry wave form. Spirometry was performed during the same visit. The FEV1 to FVC ratio was used to divide the patient visits into 2 groups with differing degrees of obstruction and the PVI was compared between the two groups using student t test.
PVI in the more obstructed group (n = 54) (mean FEV1 to FVC ratio of 0.44) was higher at 29.7 +/− 1.65 compared to the less obstructed group (n = 55) at 25.2 +/− 1.61 (mean FEV1 to FVC ratio of 0.72) and was statistically significant(p value 0.0259).
PVI may reflect degree of airway obstruction in patients with lung disease. Further studies may be needed to evaluate the place of PVI in routine clinical use.
Pulse oximetry with PVI may be a useful way to screen patients for airway obstruction where spirometry is unavailable or patients are unable to perform adequate spirometric maneuvers. In acute care settings PVI may be a quick and useful adjunct in evaluating the patient with obstructive lung disease.
Mary Zaremba, Other Radical-7 Pulse Co-oximeter was used in this study and was loaned to us by Masimo Corporation.; No Product/Research Disclosure Information