Effect of a viral filter on cardiopulmonary exercise testing

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

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 (VT) (ΔVT = 0.10 ± 0.11 L, P = 0.014). Over the entire test, the slope of the residuals for [Formula: see text]CO2 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 VT 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.

Test-retest reliability of the FitMáx©-questionnaire in a clinical and healthy population

PURPOSE

The FitMáx© was developed as a questionnaire-based instrument to estimate Cardiorespiratory Fitness (CRF) expressed as oxygen uptake at peak exercise (VO2peak). Test-retest reliability is a clinometric measurement property, which defines stability over time if multiple measurements are performed (i.e. reliability). The present study aimed to assess the test-retest reliability of the FitMáx©-questionnaire in different patient groups.

PATIENTS AND METHODS

A total of 127 cardiac, pulmonary and oncology patients and healthy subjects aged 19-84 years who completed the questionnaire twice within an average of 18 days were included for analysis. Participants were in a stable clinical situation (no acute disease or participating in a training program). To determine the test-retest reliability, the Intraclass Correlation Coefficient (ICC) and Standard Error of the Measurement (SEM) was calculated between the first (T0) and second (T1) administration of the questionnaires.

RESULTS

An excellent agreement was found between the FitMáx©-questionnaire scores at T0 and T1, with an ICC of 0.97 (SEM 1.91) in the total study population and an ICC ranging from 0.93 to 0.98 (SEM 1.52-2.27) in the individual patient groups.

CONCLUSION

The FitMáx©-questionnaire proves to be reliable and stable over time to estimate CRF of patients and healthy subjects. Trial registration NTR (Netherlands Trial Register), NL8846. Registered 25 August 2020, https://trialsearch.who.int/Trial2.aspx?TrialID=NL8846.

Re-opening the pediatric pulmonary function laboratory during the ongoing COVID-19 pandemic

The COVID-19 pandemic continues with new waves of intensification. This review provides an update based on international recommendations concerning the conduct of pulmonary function testing in a manner to limit risk to both patient and tester.

International consensus on lung function testing during COVID-19 pandemic and beyond

COVID-19 has negatively affected the delivery of respiratory diagnostic services across the world due to the potential risk of disease transmission during lung function testing. Community prevalence, reoccurrence of COVID-19 surges, and the emergence of different variants of the SARS-CoV-2 virus have impeded attempts to restore services. Finding consensus on how to deliver safe lung function services for both patients attending and for staff performing the tests are of paramount importance.

This international statement presents the consensus opinion of 23 experts in the field of lung function and respiratory physiology balanced with evidence from the reviewed literature. It describes a robust roadmap for restoration and continuity of lung function testing services during the COVID-19 pandemic and beyond.

Important strategies presented in this consensus statement relate to the patient journey when attending for lung function tests. We discuss appointment preparation, operational and environmental issues, testing room requirements including mitigation strategies for transmission risk, requirement for improved ventilation, maintaining physical distance, and use of personal protection equipment. We also provide consensus opinion on precautions relating to specific tests, filters, management of special patient groups, and alternative options to testing in hospitals.

The pandemic has highlighted how vulnerable lung function services are and forces us to re-think how long term mitigation strategies can protect our services during this and any possible future pandemic. This statement aspires to address the safety concerns that exist and provide strategies to make lung function tests and the testing environment safer when tests are required.