| Autor: |
Badas, Jenny Adriana Carvalho, Guembe, Jaime Franco, de la Flor, Celia Novials, Scadurra, Giulia Giovanna, Jaubert, Leonard, Schmartz, Denis, Turgay, Tuna, Perrin, Laurent |
| Zdroj: |
Journal of Cardiothoracic & Vascular Anesthesia; Dec2024:Supplement, Vol. 38 Issue 12, p26-27, 2p |
| Abstrakt: |
Cardiac surgery influences respiratory morbidity through multiple mechanisms. In our institution, the anesthesia team uses classic ventilation strategies: reduction of FiO2 and tidal volume, with PEEP and recruitment maneuvers. Their effectiveness is evaluated by continuous measurement of arterial oxygen saturation. But Peep is usually kept between 5 and 8 due to cardiac condition. Optimization of ventilation could still be possible. We postulate that this recruitment potential could be evaluated with the measurement of compliance and calculation of the R/I ratio (described the first time in 2020 by L.Chen & L.Brochard). ARDS Patients with a ratio >0.5 are candidates for optimization of ventilation parameters and new recruitment maneuvers. The primary endpoint is to evaluate the potential for alveolar recruitment, in patients undergoing cardiac surgery, at 2 times of the intervention (after intubation, and after cardiopulmonary bypass (CPB), by collecting the values of pulmonary compliance and the R/I ratio. The secondary endpoint is to determine if there are statistically significant differences, in terms of respiratory and hemodynamic parameters during and after recruitment. This is a prospective and observational study with agreement of our ethics committee. The 25 patients studied (Left ventricular ejection fraction above 40 %) are undergoing simple cardiac surgery (valve replacement, valve plasty or coronary artery bypass grafting). Patients' perioperative data were recorded, to evaluate the recruitment potential (Post-intubation, and post-CPB). The R/I ratio is measured with the single breath method describe by L. Chen: Peep is set at 12 mmHg during 3 min (= recruitment maneuver). "Abruptly releasing PEEP (from 12 to 5 cm H2O) increases expired volume: the difference between this volume and the volume predicted by compliance at low PEEP estimated the recruited volume by PEEP. This recruited volume divided by the effective pressure change gave the compliance of the recruited lung; the ratio of this compliance to the compliance at low PEEP gave the recruitment-to-inflation ratio". A low ratio indicate surdistension. Preliminary results show significant differences with improvement of compliance 10 min after recruitment. The median R/I was 1.58 ± 0.67 before CPB and, 1.15 ± 0.64 after CPB indicating a potential for recruitment. P/F values did not show a statistically significant increase, which could reflect good pulmonary vasoconstriction in pulmonary atelectasis. Pulmonary atelectasis aren't detectable with the ratio pO2/FiO2. Recruitment maneuvers, with moderate PEEP, are well tolerated in our patients, with a normal left ventricle (LV) ejection fraction. In conclusion R/I ratio highlights a potential for recruitment in our cardiac surgery patients. This test is hemodynamically well tolerated and could differentiate patients who are candidates for an increase in PEEP. A larger study is needed to confirm these results. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Full Text from ScienceDirect