Dynamic hyperinflation decreases after EBVs treatment

Endobronchial valves (EBVs) treatment results in a decrease in dynamic hyperinflation (DH), as shown in a study, which notes the association of such improvement with static changes.

A team of investigators conducted this prospective bi-centre study from Toulouse and Limoges Hospitals in France to assess DH during an incremental cycle ergometry before and 3 months after EBVs treatment. Their primary objective was to observe changes in inspiratory capacity (IC) at isotime.

In addition, the investigators also analysed target lobe volume reduction (TLVR) and changes in residual volume (RV), forced expiratory volume in 1 second (FEV₁), Modified Medical Research Council dyspnoea scale, 6 minutes walking distance (6MWD), BODE (body mass index, airflow obstruction, dyspnoea, and exercise), and other dynamic measures like tele-expiratory volume (EELV).

Of the 39 patients included, 38 had DH. Their IC (214 mL; p=0.004) and EELV (‒713 mL; p<0.001) at isotime improved substantially. The mean changes for FEV₁, RV, and 6MWD were 177 mL (p<0.001), ‒600 mL (p<0.0001), and 33 m (p<0.0001), respectively.

Compared with nonresponders, patients who responded on RV (>430 mL decrease) and FEV₁ (>12-percent gain) showed greater improvements (368 vs 2 mL; 398 vs ‒40 mL IC isotime, respectively).

On the other hand, patients who responded on DH (>200 mL IC isotime increase) demonstrated greater changes in TLV (‒1,216 vs ‒576 mL), FEV₁ (261 vs 101 mL), FVC (496 vs 128 mL), and RV (‒805 vs 418 mL) relative to nonresponders.

“DH is a major marker of exertional dyspnoea in severe emphysema,” the investigators said.