Airborne Particulate Concentrations During and After Pulmonary Function Testing

Abstract

Pulmonary function tests (PFTs) are an integral component of the evaluation of patients with pulmonary diseases. 1 Due to concerns for virus transmission, multiple respiratory societies recommend to postpone or limit PFTs during the coronavirus disease 2019 pandemic. [2][3][4][5][6] Repeated forced breathing maneuvers during PFTs may generate bioaerosol by airway opening 7,8 or inducing cough. 1,7 However, the concentrations of particles that are generated and change over time during and after PFTs are unknown, leading to the current recommendation to close PFT laboratories for 20 minutes to 3 hours between tests. 2-4 Thus, we investigated aerosol particle generation and clearance during and after PFTs. MethodsThis prospective observational study was conducted in three PFT laboratories located at Rush University Medical Center (room size, 3 Â 3 Â 2.8 m), Rush Oak Park Hospital (room size, 3.6 Â 4.6 Â 2.8 m), and an outpatient clinic (room size, 3.4 Â 4.6 Â 2.8 m) with air exchange frequencies of five, three, and nine times/h, respectively. Adult patients whose condition required PFTs were enrolled after screening negative for coronavirus disease 2019. The study was approved, and informed consent was waived by the ethics committee at Rush University.

Real-life measurement of size-fractionated aerosol concentration in a plethysmography box during the COVID-19 pandemic and estimation of the associated viral load

“…Present results seem to underpin this hypothesis, as in the case of 69% of the measurements we could detect a statistically significant increase of particle concentration. The increase was slightly higher than that obtained by [8] but lower than those reported by [7]. It is worth noting that four patients had a cough during the measurements, which may have further increased the number of generated particles.…”

“…Present real-life measurements were completed at 15-20 min intervals based on the recommendations of the Hungarian Respiratory Society advising maximum four measurements per hour. Based on the observations of previous investigators [7], this time interval may not have been enough to reach background levels, so present results could virtually contain an accumulation component. However, the analysis of our measurement results demonstrated that PFTs completed later did not generate a statistically relevant higher number of particles than the first tests.…”

Risk and mitigation of aerosolisation from lung function testing: results from the AERATOR study

“…The third paper (20) analysed aerosol presence whilst a variety of pulmonary function tests (PFTs) were performed by 28 patients with viral filters in rooms with three different ACH rates. Just one measure of aerosol (OPS) was performed during PFTs and for 30-60 minutes following the procedure after the patients and researchers had left the room.…”

How Local SARS-CoV-2 Prevalence Shapes Pulmonary Function Testing Laboratory Protocols and Practices During the COVID-19 Pandemic

“…Most laboratories' institutional policies considered PFTs collectively to be high AGP, in line with recent evidence. 7,8 Implementation of some practices varied depending on local prevalence, whereas others did not. For example, PCR testing was more likely to be adopted in high prevalence areas in comparison with low or medium prevalence areas, whereas N95 respirator usage among laboratories was relatively uniform.…”