SESSION TITLE: Unique Uses of Pulmonary Function Tests
SESSION TYPE: Rapid Fire Original Inv
PRESENTED ON: 10/19/2022 11:15 am - 12:15 pm
PURPOSE: Breathlessness, fatigue, and exertional intolerance can persist for several months in up to 50% people after recovery from SARS-CoV-2 infection. The physiological underpinning(s) of the reduced exercise capacity associated with post-acute sequelae of SARS-CoV-2 infection (PASC) requires further investigation. We characterized pulmonary function relative to normative values and determined the relationship between measures of pulmonary function and peak pulmonary O2 uptake (V̇O2peak) in people with PASC.
METHODS: Pulmonary function [including lung diffusing capacity for carbon monoxide (DLCO), and maximal inspiratory pressure (MIP)] and the cardiopulmonary responses to maximal incremental treadmill exercise (CPET) were assessed in ten adults (five females; age 41 ± 11 y; BMI 21 ± 5 kg/m2) with PASC. Time from initial SARS-CoV-2 infection to study enrollment was 6 ± 4 months. At the time of study, participants (n) reported persistent fatigue (9), breathlessness (9), headache (6), chest tightness (4), cough (2), muscle pain (4), palpitations (4), dizziness (5), and nausea (1).
RESULTS: There was inter-individual heterogeneity in total lung capacity (TLC; range 68 to 117% predicted), forced vital capacity (FVC; range 73 to 123% predicted), forced expiratory volume in 1 s (FEV1; 92 to 109% predicted), and maximal voluntary ventilation (MVV; range 75 to 122% predicted); however, no group mean measure of spirometric function or lung volume was different relative to normative values. Conversely, group mean DLCO (21 ± 9 vs. 27 ± 5 ml/min/mmHg, P = 0.017) and MIP (75 ± 43 vs. 102 ± 18 cmH2O, P = 0.049) were reduced relative to normative values. During the CPET, peak RER and heart rate were 1.16 ± 0.12 and 174 ± 16 beats/min (97 ± 8% predicted), respectively. V̇O2peak was 27.3 ± 6.8 ml/kg/min (90 ± 20% predicted, range 49-122% predicted, V̇O2peak <85% predicted in 4 of 10 participants), and there was no clear evidence of ventilatory or gas exchange impairment to exercise (breathing reserve 49 ± 31 L; minimum SpO2 96 ± 2%; V̇E/V̇CO2 nadir 27 ± 2; ∆PETCO2 7.4 ± 2.8 mmHg). There was no relationship between percent predicted V̇O2peak and percent predicted TLC (r 2 = 0.061, P = 0.492), FVC (r 2 = 0.196, P = 0.200), FEV1 (r 2 = 0.173, P = 0.232), MVV (r 2 = 0.037, P = 0.595), DLCO (r 2 = 0.007, P = 0.836), and MIP (r 2 = 0.007, P = 0.820).
CONCLUSIONS: Impaired pulmonary function and decreased exercise capacity are present in some but not all people with PASC who report persistent fatigue and breathlessness. Presently, we find no relationship between pulmonary function and V̇O2peak in people with PASC.
CLINICAL IMPLICATIONS: Some but not all people with PASC have normal exercise capacity within ~2-12 months after recovery from SARS-CoV-2 infection. CPET may be considered when evaluating the presence and mechanistic underpinning(s) of impaired exercise capacity in such individuals.
DISCLOSURES: No relevant relationships by Natalie Bonvie-Hill
No relevant relationships by Igor Fernandes
No relevant relationships by Augustine Lee
No relevant relationships by Amy Lockwood
No relevant relationships by Bala Munipalli
No relevant relationships by Tathagat Narula
No relevant relationships by Brian Shapiro
Competitive research grant recipient relationship with Gilead Sciences Inc. Please note: 1 year Added 03/30/2022 by Bryan Taylor, value=Grant/Research Support