PURPOSE:The demand by patients who require oxygen supplementation for increased mobility, air travel and desire to maintain normal functionality has led to the introduction of portable oxygen concentrators (POC). The purpose of our study was to evaluate the oxyhemoglobin response to exercise while using currently available POCs.
METHODS:Patients with COPD who required supplemental oxygen use with exercise were recruited. Each patient underwent a ten minute treadmill walk at a comfortable pace using continuous flow oxygen. During two subsequent visits, each was randomized to two of four test units including three POCs (Sequal Eclipse, Inogen One, and Respironics Evergo), and one concentrator filled portable pulse device (Invacare Homefil). Each patient then underwent a 10 minute treadmill walk with each POC at the “number” setting determined during the continuous flow oxygen titration. Each test was separated by a 30 minute rest period. Heart rate, pulse oximetry, walking distance, subjective dyspnea and muscle fatigue were measured during the test. The test was terminated if oxyhemoglobin saturation fell below 85% or at the patient's request to stop the test for dyspnea or muscle fatigue.
RESULTS:A total of 15 patients (4 males and 11 females with a mean age of 63 years) were enrolled and completed the study. The mean saturations per device during activity were as follows: Eclipse 93%, Inogen 89%, Evergo 91%, Homefil 90%. The mean walking distance per device was as follows: Eclipse 260 meters, Inogen 144 meters, Evergo 257 meters, Homefil 268 meters. Data analysis was performed using analysis of variance (ANOVA.)No statistical differences in either exercise saturation or walking distance were noted when comparing the four tested devices. (F 0.9043). Variability in individual patient response was noted in some instances.
CONCLUSION:Walking distance and oxyhemoglobin saturation did not differ significantly during exercise among three types of portable oxygen concentrators or Homefil device in this group of fifteen patients.
CLINICAL IMPLICATIONS:Patients should undergo exercise oxygen prescription using the device that ultimately will be used on a daily basis.
DISCLOSURE:Vijay Subramaniam, No Financial Disclosure Information; No Product/Research Disclosure Information