Éditeur(s) : HAL CCSD
Résumé : International audience
BACKGROUND: The effects of pressure-controlled (PC) ventilation on the ventilatory and haemodynamic parameters during laparoscopy procedures had not been carefully assessed. This prospective cross-over study was undertaken to compare how volume-controlled (VC) and PC modes could affect pulmonary mechanics, gas exchange, and cardiac function in patients undergoing laparoscopy. METHODS: Twenty-one patients undergoing laparoscopic urological procedures had their lungs ventilated at the beginning with VC ventilation. PC ventilation was instituted at the end of the VC sequence. Ventilator settings were adjusted to keep tidal volume, respiratory rate, and Fi(o(2)) constant in every mode. A complete set of ventilatory, haemodynamic, and gas exchange parameters was obtained under VC after 40 min of pneumoperitoneum and 20 min after switching for PC. Transoesophageal echocardiography was performed in order to evaluate systolic and diastolic function of the heart. RESULTS: When VC was switched to PC, peak airway pressure decreased [mean (sd) 32 (6) vs 27 (6) cm H(2)O; P < 0.0001], peak inspiratory flow increased [17 (3) vs 48 (8) litre min(-1); P < 0.0001), and dynamic compliance improved [+15 (8)%]. No difference was noted for static airway pressure, static compliance, and arterial oxygenation. No significant change could be demonstrated in the systolic [left ventricular end-systolic wall stress 66 (16) vs 63 (14) x 10(3) dyn cm(-2) m(-2)] or diastolic function [early diastolic velocity 10.3 (2.5) vs 10.5 (2.7) cm s(-1)]. CONCLUSIONS: In this study, no short-term beneficial effect of PC ventilation could be demonstrated over conventional VC ventilation in patients with pneumoperitoneum.
BJA

hal-00689758
https://hal.archives-ouvertes.fr/hal-00689758
DOI : 10.1093/bja/aem166
PUBMED : 17626027

Éditeur(s) : HAL CCSD
Résumé : International audience
BACKGROUND: Dairy working increases the prevalence of lower airway respiratory diseases, especially COPD and asthma. Epidemiological studies have reported that chronic inhalation of organic dusts released during specific daily tasks could represent a major risk factor for development of these pathologies in dairy workers. Knowledge on size, nature and biological activity of such organic dusts remain however limited. OBJECTIVE: To compare size distribution, microbial composition and cellular effects of dusts liberated by the spreading of straw bedding in five French dairy farms located in Brittany. RESULTS: Mechanized distribution of straw bedding generated a cloud of inhalable dusts in the five dairy farms' barns. Thoracic particles having a 3-7.5µm size constituted 58.9-68.3% of these dusts. Analyses of thoracic dusts by next generation sequencing showed that the microbial dust composition differed between the five French farms, although Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria represent more than 97.5% of the bacterial phyla detected in each sample. Several bacteria genera comprising of human pathogenic species, such as Pseudomonas, Staphylococcus, Thermoactinomyces or Saccharopolyspora were identified. Cladosporium and Alternaria fungal genera, which are potent environmental determinants of respiratory symptoms, were detected in dusts collected in the five farms and their levels reached 15.5-51.1% and 9-24.7% of assignable fungal sequences in each sample, respectively. Finally, all dust samples significantly and strongly increased the expression of the pro-inflammatory TNF-α, IL-1β, IL-6 and IL-8 cytokines at both mRNA and protein levels in human monocyte-derived macrophages. Their effects were dose-dependent and detectable from 1µg/ml. The intensity of the macrophage responses however differed according to the samples. CONCLUSIONS: Our results strengthen the hypothesis that organic dusts released during the distribution of straw bedding are mainly constituted of thoracic particles which are small enough to deposit on lower bronchial epithelium of dairy farmers and induce inflammation.
Environmental Research

hal-01579610
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01579610
DOI : 10.1016/j.envres.2017.07.025
PUBMED : 28735230