The goal of this clinical trial was to compare the action of long-acting ß2-agonists (LABA-olodaterol) and muscarinic antagonists (LAMA-tiotropium) on tissue oxygenation in COPD considering their impact on proximal and peripheral ventilation and, eventually, on lung capillary volume. The hypothesis was that LABA would have a more peripheral effect than LAMA (due to the opposite gradient of their receptors) and better peripheral ventilation would result in a greater oxygenation. Before and after LABA (visit 1) and LAMA (visit 2) inhalation, COPD participants were asked to perform single-breath washout and forced oscillation tests, double diffusion technique and spirometry, while transcutaneous oxygenation was continuously recorded.
Slopes of He (SHe) and SF6 (SSF6) from single-breath washout test (SBWO) (assessing ventilation heterogeneities at the level of pre- and intra-acinar bronchioles, respectively) (quadruple model, LR6000 Logan-Sinclair, Rochester, UK), respiratory system resistance (R5, R5-R19) and reactance (X5, AX, Fres) from forced oscillation test (FOT) (Resmon Pro, ResTech, Italy), lung capillary volume (Vc) from double diffusion of NO and CO (DLNO/DLCO) (Hyp'Air compact, Medisoft, Dinant, Belgium), and FEV1 from spirometry (Zan®, Oberthulba, Germany) were evaluated before and after LABD administered via a spacer device: during the first visit, before, 30 minutes and 2 hours after inhalation of 4 puffs of 2,5 µg of olodaterol (LABA); during the second visit, before, 40 minutes and 2 hours after the administration of 4 puffs of 2,5 µg of tiotropium (LAMA). Transcutaneous oximetry (Perimed232©, Järfälla, Sweden) was monitored continuously during the 2 hours of each visit.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
30
Erasme University Hospital
Brussels, Belgium
Tissue oxygenation (TcO2) change from baseline
Transcutaneous oxygen (TcO2) evaluated continuously with a transcutaneous oximeter
Time frame: 120 minutes post-drug-administration
Tissue oxygenation (TcO2) change from baseline
Transcutaneous oxygen (TcO2) evaluated continuously with a transcutaneous oximeter
Time frame: 30 (LABA)/40 (LAMA) minutes post-drug administration
Slope of Helium (SHe) change from baseline
SHe from single-breath washout test (SBWO) assessing peripheral ventilation heterogeneities
Time frame: 120 minutes post-drug administration
Slope of Helium (SHe) change from baseline
SHe from single-breath washout test (SBWO) assessing peripheral ventilation heterogeneities
Time frame: 30 (LABA)/40 (LAMA) minutes post-drug administration
Area under reactance curve from 5 Hz (AX) change from baseline
AX from forced oscillation test (FOT) evaluating the peripheral lung function
Time frame: 120 minutes post-drug administration
Area under reactance curve from 5 Hz (AX) change from baseline
AX from forced oscillation test (FOT) evaluating the peripheral lung function
Time frame: 30 (LABA)/40 (LAMA) minutes post-drug administration
Reactance at 5 Hz (X5) change from baseline
X5 from forced oscillation test (FOT) also evaluating the peripheral lung function
Time frame: 30 (LABA)/40 (LAMA) minutes post-drug administration
Resonant frequency (Fres) change from baseline
Fres from forced oscillation test (FOT) also evaluating the peripheral lung function
Time frame: 120 minutes post-drug administration
Resonant frequency (Fres) change from baseline
Fres from forced oscillation test (FOT) also evaluating the peripheral lung function
Time frame: 30 (LABA)/40 (LAMA) minutes post-drug administration
Peripheral resistance (R5-R19) change from baseline
Peripheral resistance, assessed as frequency dependence of resistance (R5-R19) from forced oscillation test (FOT) also evaluating the peripheral lung function
Time frame: 120 minutes post-drug administration
Peripheral resistance (R5-R19) change from baseline
Peripheral resistance, assessed as frequency dependence of resistance (R5-R19) from forced oscillation test (FOT) also evaluating the peripheral lung function
Time frame: 30 (LABA)/40 (LAMA) minutes post-drug administration
Lung capillary volume (Vc) change from baseline
Vc from single-breath double diffusion technique of nitric oxide (NO) and carbon monoxide (CO) (DLNO/DLCO)
Time frame: 120 minutes post-drug administration
Lung capillary volume (Vc) change from baseline
Vc from single-breath double diffusion technique of nitric oxide (NO) and carbon monoxide (CO) (DLNO/DLCO)
Time frame: 30 (LABA)/40 (LAMA) minutes post-drug administration
Forced Expiratory Volume in 1 Second (FEV1) change from baseline
FEV1 from spirometry
Time frame: 120 minutes post-drug administration
Forced Expiratory Volume in 1 Second (FEV1) change from baseline
FEV1 from spirometry
Time frame: 30 (LABA)/40 (LAMA) minutes post-drug administration
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