Étiquette : Lung physiology

Anesthésie · Vol. 21 Abstracts 2017

A-01 – Effets pulmonaires d’une ventilation open-lung en chirurgie cardiaque sous CEC : une étude en tomographie par impédancemétrie électrique
Benoît Guinard, David Lagier, Catherine Guidon Service d’anesthésie-réanimation cardiovasculaire, AP-HM, CHU La Timone, Marseille   Objectif : Une ventilation protectrice selon l’approche open-lung pourrait prévenir les complications respiratoires postopératoires (atélectasies). La tomographie par impédancemétrie électrique (TPIE) permet d’apprécier l’aération pulmonaire de façon dynamique. Méthode : Dans le groupe « ventilation protectrice open lung » (VPOL, n = 23), les patients ont reçus plusieurs manœuvres de recrutement, une PEP à 8 cm H2O et maintien d’une ventilation ultraprotectrice en per-CEC. Dans le groupe « ventilation conventionnelle » (VC, n = 19), la PEP était maintenue à 2 cm H20 sans réalisation de manœuvre de recrutement et la ventilation per-CEC était interrompue. Plusieurs enregistrements successifs ont été réalisés en ventilation spontanée (J-1, J1, J2) et sous ventilation mécanique (pré/post-CEC). La variation relative d’impédance lors du cycle ventilatoire (rel. ∂Z) et l’impédance pulmonaire en fin d’expiration (EELI) ont été analysées au niveau global et régional. Quatre régions pulmonaires d’intérêt ont été étudiées : 2 ventrales (R1 et R2) et 2 dorsales (R3 et R4). Le center of ventilation (COV) représentant la distribution dorso-ventrale de la ventilation, a été défini par : rel. ∂Z(R3+R4)/rel. ∂Z global. La compliance relative (RCOMP) a été définie par : rel. ∂Z/(Pplat-PEP). Résultat : La mise sous ventilation mécanique se traduit par une diminution du COV (redistribution ventrale de la ventilation). Dans le groupe VPOL, le COV est significativement plus important en pré (VPOL 38,4 ± 7,9 % vs VC 26,9 ± 8,4 %, p < 0,0001) et post-CEC (VPOL 36,6 ± 9,5 % vs VC 29,5 ± 9,2 %, p = 0,02). Au niveau dorsal (R3+R4), la RCOMP est significativement plus élevée dans le groupe VPOL en pré (VPOL 133,3 ± 88,1U/cm H2O vs VC 61,5 ± 51,8U/cm H2O, p = 0,006) et post-CEC (VPOL 163,2 ± 130,7U/cm H2O vs VC 77,9 ± 65,4, p = 0,02). L’EELI dorsale postopératoire est significativement plus élevée dans le groupe VPOL à J1 (VPOL 129,6 ± 128,2U vs VC 46 ± 18,4U, p = 0,03). Une tendance identique est retrouvée à J2. Conclusion : La ventilation protectrice selon l’approche open-lung diminue la redistribution ventrale de la ventilation induite par la ventilation contrôlée. Il existe une amélioration de l’EELI dorsale lors du retour en ventilation spontanée.     Pulmonary effect of perioperative open-lung protective ventilation during cardiac surgery: an electrical impedance tomography study   Objectives: Perioperative open-lung ventilation may prevents pulmonary atelectasis. Electrical impedance tomography (EIT) allows a dynamic evaluation of pulmonary aeration at bedside. Methods: In the open-lung protective ventilation group (OLPV, n=23), patients were ventilated with high PEEP (8 cm H2O) and were exposed to repeated alveolar recruitment maneuvers and ultraprotective ventilation during cardiopulmonary bypass (CPB). In the conventional ventilation group (CV, n=19), patients were ventilated with low PEEP (2 cmH2O); no recruitment maneuvers were operated and ventilation was stopped during CPB. Different recordings were realized: in spontaneous ventilation(day -1, day 1, day 2) and under volume controlled-ventilation (pre/post CPB). Four regions of interest (ROI) were defined as 4 pulmonary quadrants: 2 ventral (R1 and R2) and 2 dorsal (R3 and R4). The relative impedance variation during tidal volume (rel. ∂Z) and the end expiratory lung impedance (EELI) were analyzed at the global and regional level. The center of ventilation (COV) index was calculated by dividing the sum of the dorsal rel. ∂Z (R3+R4) by the global rel. ∂Z. The relative compliance (RCOMP) was defined by rel. ∂Z / (plateau pressure - PEEP). Results are expressed as mean ± SD. Results: In the global population, a significant decrease of the COV (ventral redistribution of ventilation) occurred along with induction of general anesthesia and initiation of volume-controled ventilation. COV was significantly higher in the OLPV group before (OLPV 38.4±7.9% vs CV 26.9±8.4%, P<0.0001) and after CPB (OLPV 36.6±9.5% vs CV 29.5±9.2%, P=0.02). Under spontaneous ventilation, COV values were similar between groups. In the dorsal region (R3+R4), RCOMP was significantly higher in the OLPV group before (OLPV 133.3±88.1 U/cmH2O vs CV 61.5±51.8 U/cm H2O, P=0.006) and after CPB (OLPV 163.2±130.7 U/cm H2O vs CV 77.9±65.4, P=0.02). Dorsal EELI (R3+R4) decreased after induction of general anesthesia and postoperatively. Dorsal EELI (R3+R4) was significantly higher in the OLPV group (OLPV 129.6±128.2 U vs VC 46 ± 18.4 U, P=0.03) at day 1. Same trend was found at day 2 without reaching significance. Conclusion: Perioperative open-lung ventilation prevents the ventral redistribution of ventilation induced by general anesthesia and controlled mechanical ventilation, underlying the formation of dorsal atelectasis. As a result, postoperative dorsal EELI was preserved after recovering spontaneous ventilation.   Séance : Communications libres anesthésie - vendredi 9 juin - 8:00-10:00
mai 24, 2017
Vol. 20 JA2016 - thoracic

T-16 Using bronchial biopsy as a tool for study of airway remodeling in severe or non-severe asthmatic patient
Matthieu Thumerel, Pierre-Olivier Girodet, Patrick Berger, Roger Marthan, Jacques Jougon Institution : Service de chirurgie thoracique, hopital Haut-lévêque, CHU Bordeaux, Pessac Objectives : Evaluate the use of bronchial biopsy during bronchoscopy as a tool for study of airway remodeling in severe or non-severe asthmatic patients. Methods : In two studies (Remodelasthme, NCT00896428 and Mitasthme, NCT00808730), were performed 92 bronchoscopies among patients with severe and non-severe asthma. Three biopsies per patient of spurs segmental or sub-segmental from the middle lobe were made for an analysis of 6-8 sections per biopsy of bronchial smooth muscle (BSM) area, a marker of asthmatic airway remodeling. Results : In Mitasthme study, 30 non-severe asthmatic patients were biopsied. Only 2 bronchoscopies were unusable. Between and within-biopsies variability of BSM area were similar in “small muscle” vs “big muscle” groups (coefficient of 0.32 vs. 0.34; p = 0.45). These study have identified a phenotype called “big muscle” in non-severe asthmatic patients whose clinical characteristics are similar to severe asthma. In Remodelasthme study, 31 patients with severe asthma were biopsied twice. Intra-observer and inter-observers reproducibility of BSM area was good. Between and within-biopsies variability of BSM area were similar in gallopamil vs. placebo groups to 2 times. The study concluded that gallopamil is able to reduce the BSM thickness in severe asthmatic patients. Conclusion : Bronchoscopy with biopsy is a good tool for an analysis of the bronchial smooth muscle. It remains invasive and development of other markers is needed.
novembre 29, 2016