Comparison of a portable device versus a specific spirometer for cough flow testing

Introduction: Cough peak flow (CPF) is a simple measure of cough mechanics, but figures may vary depending on the measurement instrument used. Objectives: to compare CPF measured by a portable peak flow meter (asmaPLAN+, Vitalograph) (CPFa) and by a pneumotacograph (Spirotrac, Vitalograph) with PCF testing dedicated software (CPFe). Results: Fifty-four patients and heathy volunteers (32 male and 22 female) with mean age of 43 years (min 21-max 88) were studied. Forteen had spinal cord injury, 7 multiple sclerosis, 6 stroke, 1 confluent multiple mononeuropathy, 1 motor and sensory polyneuropathy, 1 brain tumor, 1 rheumatoid arthritis, 1 lung transplant, 1 Guillain-Barre syndrome, 1 lateral amyotrophic sclerosis and 20 normal controls. The mean (+/- SD) CPFa rates were 361,1 L/min (153,4 L/min) and the CPFe rates were 389,3 L/min (143,3 L/min), an average difference of 28,2 L/min between measurement methods, which is statistically significant, with a p value Conclusions: In this evaluation, including patients with heterogeneous disorders and normal controls, CPF readings were on average significantly higher when measured using the equipment with the CPF testing dedicated software; moreover this device allows for a better assessment of the cough maneuvers including visualization of the cough flow-volume loops.