[abstract] SPIROMETRIC CHANGES WITH LONG TERM HYPERBARIC OXYGEN THERAPY: A PROSPECTIVE STUDY.

Abstract

BACKGROUND: Prolonged exposure to elevated oxygen concentration has been reported to result in detrimental outcomes.1 The purpose of this study is to determine if long-term HBOT causes any significant spirometric changes reflective of pulmonary injury. MATERIALS AND METHODS: A prospective study of spirometric testing is performed on 29 subjects prior to the first HBOT treatment, then again after every 5 consecutive treatments until completion of treatment course. Repeated follow-up testing was done at 3, 6 and 12-month intervals. Various respiratory parameters obtained over time are recorded and analyzed for statistical significance. RESULTS: 29 patients (20 males and 9 females) were enrolled with an average age of 61.3 years old. Patients had a variety of diagnoses including radionecrosis (41.4%), diabetic wound (31.0%), compromised graft (17.2%), and osteomyelitis (10.3%). All patients completed a minimum of 20 treatments. Changes in respiratory parameters over time showed no statistical significance (p>0.05). See table below. Respiratory Measurements of Patients undergoing HBOT over Time; Respiratory Parameters P-values*; Forced Vital Capacity (FVC) 0.27; Forced Expiratory Volume in one second (FEV1) 0.12; FEV1/FVC 0.44; Forced Expiratory Volume in six seconds (FEV6) 0.31; FEV1/FEV6 0.34; Peak Expiratory Flow 0.84; Forced Expiratory Flow at 25% and 75% FVC 0.34; Forced Inspiratory Vital Capacity 0.68; Peak Inspiratory Flow 0.37; Maximum Vital Capacity 0.38; Maximum Voluntary Ventilation 0.28; * P-values calculated using repeated measures Paired T-Test.; CONCLUSIONS: This preliminary study revealed no significant statistical differences in spirometric parameters of patients undergoing long-term HBOT. Further investigation on a larger patient population is ongoing at this time. Reference: 1McAdams RM, Mustafa SB, Shenberger JS, PS, Henson BM, Digeromino RJ. Cyclic stretch attenuates the effects of hyperoxia on cell proliferation and viability in human alveolar epithelial cells. Am J Physiol Lung Cell Mol Physiol; doi:10.1152/ajplung.00160.2005, Feb 3 2006.