title: Effects on membrane lung gas exchange of an intermittent high gas flow recruitment maneuver: preliminary data in veno-venous ECMO patients.
abstract: Gas exchange capabilities of polymethylpentene membrane lungs (MLs) worsen over time. ML deterioration is related to protein deposit and clot formation. Condensation and trapping of water vapor inside ML hollow fibers might affect ML performances as well. Increasing sweep gas flow (GF) could remove such fluid. The purpose of this study was to evaluate the effects on ML gas exchange of a recruitment maneuver (RM) based on a brief increase in GF, during veno-venous ECMO support. Short-term (15 min) effects of 20 RMs were assessed. RM raised ML CO2 removal from 149 ± 37 to 174 ± 41 ml/min (p < 0.001). Conversely, RM did not improve ML O2 transfer (155 ± 31 and 158 ± 31 ml/min before and after RM, respectively). ML outlet pCO2 decreased after RM from 51.2 ± 5.8 to 45.8 ± 5.4 mmHg (p < 0.001), while ML outlet pO2 increased from 520 ± 61 to 555 ± 51 mmHg (p < 0.001). Both ML dead space and shunt fractions decreased from 47.8 ± 15.3 to 29.6 ± 14.7 % (p < 0.001) and from 8.8 ± 4.2 to 7.0 ± 3.8 % (p < 0.001), respectively. Furthermore, a subset of 5 RMs was evaluated on a 6-h time frame. The beneficial effects on ML performances due to the RM gradually diminished and waned over a 6-h interval after the RM. The RM improved ML CO2 removal substantially, albeit temporarily. ML oxygenation performance was marginally affected.
authors: Dipartimento di Scienze della Salute, Università degli Studi di Milano Bicocca, via Cadore 48, 20052, Monza, Italy, castagnaluigi1983@gmail.com.
authors: Luigi
authors: L
authors: Castagna
authors: Alberto
authors: A
authors: Zanella
authors: Vittorio
authors: V
authors: Scaravilli
authors: Federico
authors: F
authors: Magni
authors: Salua Abd El Aziz El Sayed
authors: SA
authors: Deab
authors: Michele
authors: M
authors: Introna
authors: Francesco
authors: F
authors: Mojoli
authors: Giacomo
authors: G
authors: Grasselli
authors: Antonio
authors: A
authors: Pesenti
authors: Nicolò
authors: N
authors: Patroniti
mesh_terms: D000328:Adult; D015331:Cohort Studies; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012131:Respiratory Insufficiency / Q000503:physiopathology / Q000628:therapy*; D013990:Tidal Volume / Q000502:physiology; D013997:Time Factors; D016896:Treatment Outcome