Ventilator-Associated Pneumonia. Mucus Slurper. Mucuciliary Transport.

项目 1. 气管定向和肠内营养在呼吸机相关性肺炎中的作用 肺炎 主题：13只猪 结果如下：气管方向高于水平30度的猪（半卧位的模型，被认为是当前最佳临床实践）发生肺炎。 相反，保持头低脚高位的猪没有发生肺炎，尽管呼吸机相关性肺炎有两个主要风险因素（机械通气长达一周和肠内喂养）。 2. 使用放气袖带在头低脚高位进行安全机械通气的可能性。 主题：4只猪 结果如下：尽管存在放气袖带，但用放气袖带通气长达一周的猪没有发生肺炎或肺定植，因为分泌物是重力排出的。 3. 双层乳胶气管插管套囊的体内评价。 受试者：9只猪（5只使用新袖带，4只作为对照） 结果：防漏套囊似乎是安全的，没有证据表明气管病变。 机械通气72小时后，袖带未出现损坏。 与对照组相比，半卧位的肺定植减少。 4. 通过碳酸氢盐超滤去除二氧化碳。 主题：7只羊 结果如下：我们使用市售的血液过滤器（巴克斯特HA-2000）有效地去除了碳酸氢盐形式的二氧化碳;使用不含碳酸氢盐的置换液，保持强离子差和pH恒定。 这个过程似乎是安全的。 5. 新型Lycra原型袖带的体内测试（正在进行）。 主题：3只猪 结果：我们在体内测试了新的莱卡袖带。 我们没有泄漏（用亚甲蓝评估），也没有气管损伤的证据。 6. 原发性急性呼吸窘迫综合征模型肺灌注的研究 比较CT扫描和MRI作为ARDS成像和估计肺复张程度的工具（正在进行）。 主题：4只猪 半卧位通气的猪出现肺炎和呼吸衰竭。 这种呼吸衰竭符合ARDS的所有标准。 我们研究了微球注射的肺灌注及其对PEEP增加和身体旋转（ICU中常用的两种策略，以改善患者的氧合）的反应。 在3个不同PEEP水平下，以及在翻身（从俯卧到仰卧）时，用CT扫描和MRI对猪进行成像。

Projects 1. The respective role of tracheal orientation and enteral feeding, in Ventilator Associated Pneumonia. Subject: 13 pigs Results: pigs with the tracheal orientation 30 degrees above the horizontal (a model of the semi-recumbent position, considered best current clinical practice), developed pneumonia. Instead, pigs kept in the Trendelenburg position did not develop pneumonia, despite two major risk factors for Ventilator Associated Pneumonia (mechanical ventilation for up to one week, and enteral feeding). 2. Possibility of safe mechanical ventilation in Trendelenburg position with a deflated cuff. Subject: 4 pigs Results: pigs ventilated up to one week with a deflated cuff did not develop pneumonia or lung colonization despite the presence of a deflate cuff since secretions were gravitationally drained. 3. In-vivo evaluation of double-layer Latex tracheal tube cuff. Subject: 9 pigs (5 with new cuff and 4 acting as controls) Results: the leak-proof cuff appeared to be safe with no evidence of tracheal lesions. The cuff appeared not damaged after 72 hours of mechanical ventilation. Lung colonization in the semi-recumbent position was reduced compared to controls. 4. Carbon-dioxide removal via bicarbonate ultrafiltration. Subject: 7 sheep Results: we removed carbon dioxide effectively in the form of bicarbonates, using a commercial Hemofilter (Baxter HA-2000); with replacement solution devoid of bicarbonate, keeping the strong ion difference, and the pH constant. The process appeared to be safe. 5. In-vivo testing of the new Lycra prototype cuff (ongoing). Subject: 3 pigs Results: we tested the new Lycra cuff in-vivo. We had no leakage (as assessed with methylene blue), and no evidence of tracheal damage. 6. Study of lung-perfusion in a model of primary-ARDS. Comparison of CT-scan and MRI as a tool to image ARDS and estimate degree of lung recruitment (ongoing). Subject: 4 pigs Pigs ventilated in the semi-recumbent position developed pneumonia and respiratory failure. Such respiratory failure meets all criteria for ARDS. We studied lung perfusion with microsphere injection, and its response to PEEP increase and body rotation (two maneuvers commonly employed in ICU to improve patient oxygenation). Pigs were imaged both with CT scan and MRI at 3 different PEEP levels, and when turned (from prone to supine).