Lack of effect of an in-line filter on cardiopulmonary exercise testing variables in healthy subjects.

Abbasi A; Division of Respiratory and Critical Care Physiology and Medicine, Harbor-UCLA Medical Center,
Ahmad K; Ferguson C; Soriano A; Calmelat R;Rossiter HB; Casaburi R; Stringer WW; Porszasz J

European journal of applied physiology [Eur J Appl Physiol] 2023 Oct 06.
Date of Electronic Publication: 2023 Oct 06.

Purpose: Pathogen transmission during cardio-pulmonary exercise testing (CPET) is caused by carrier aerosols generated during respiration.
Methods: Ten healthy volunteers (age range: 34 ± 15; 4 females) were recruited to see if the physiological reactions to ramp-incremental CPET on a cycle ergometer were affected using an in-line filter placed between the mouthpiece and the flow sensor. The tests were in random order with or without an in-line bacterial/viral spirometer filter. The work rate aligned, time interpolated 10 s bin data were compared throughout the exercise period.
Results: From rest to peak exercise, filter use increased only minute ventilation ([Formula: see text] E ) (Δ[Formula: see text] E  = 1.56 ± 0.70 L/min, P < 0.001) and tidal volume (V T ) (ΔV T  = 0.10 ± 0.11 L, P = 0.014). Over the entire test, the slope of the residuals for [Formula: see text]CO 2 was positive (0.035 ± 0.041 (ΔL/L), P = 0.027). During a ramp-incremental CPET in healthy subjects, an in-line filter increased [Formula: see text] E and V T but not metabolic rate.
Conclusion: In conclusion, using an in-line filter is feasible, does not affect appreciably the physiological variables, and may mitigate risk of aerosol dispersion during CPET.