Tactical and Enroute Care Research Department, United States Army Institute of Surgical Research, Joint Base San Antonio-Fort Sam Houston, San Antonio, Texas.
Comparative Pathology Department, United States Army Institute of Surgical Research, Joint Base San Antonio-Fort Sam Houston, San Antonio, Texas.
J Appl Physiol (1985). 2021 May 1;130(5):1337-1344. doi: 10.1152/japplphysiol.01048.2020. Epub 2021 Mar 18.
Airway management is important in trauma and critically ill patients. Prolonged mechanical ventilation results in overventilation-induced lung barotrauma, but few studies have examined the consequence of acute (1 h or less) overventilation. We hypothesized that acute hyperventilation, as might inadvertently be performed in prehospital settings, would elevate systemic inflammation and cause lung damage. Female Yorkshire pigs (40-50 kg, = 10/group) were anesthetized, instrumented for hemodynamic measurements and blood sampling, and underwent a 25% controlled hemorrhage followed by 1 h of ) spontaneous breathing, ) "normal" bag ventilation (4.8 L·min volume, ∼400 mL tidal volume, 12 breaths/minute), ) bag hyperventilation (9 L·min volume, ∼750 mL tidal volume, 12 breaths/minute), ) maximum hyperventilation (15 L·min volume, ∼750 mL tidal volume, 20 breaths/minute), or ) mechanical ventilation. Pigs then regained consciousness and recovered for 24 h, followed by euthanasia and collection of blood and tissue samples. No level of manual ventilation had any significant impact on hemodynamic variables. Blood markers of tissue damage and plasma cytokines were not statistically different between groups with the exception of a transient increase in IL-1β; all values returned to baseline by 24 h. On pathological review, severity and distribution of lung edema or other gross pathologies were not significantly different between groups. These data indicate hyperventilation causes no adverse effects, to include inflammation and tissue damage, and that acute overventilation, as could be seen in the prehospital phase of trauma care, does not produce evidence of adverse effects on the lungs following moderate hemorrhage. Appropriate airway management is essential in trauma and critically ill patients. Prolonged mechanical ventilation can result in overventilation-induced lung barotrauma, but few studies have examined the consequence of acute overventilation. We investigated the outcome of hemorrhage followed by 1 h of overventilation in swine. We found that acute overventilation, as could be seen in the prehospital phase of trauma care, does not produce evidence of adverse effects on otherwise healthy lungs following moderate hemorrhage.
气道管理在创伤和危重症患者中非常重要。长时间的机械通气会导致过度通气引起的肺气压伤，但很少有研究探讨急性（1 小时或更短时间）过度通气的后果。我们假设，在院前环境中可能无意中进行的急性过度通气会增加全身炎症并导致肺损伤。雌性约克夏猪（40-50kg，每组 10 只）麻醉后，进行血流动力学测量和血液取样，并进行 25%的控制性出血，然后进行 1 小时的）自主呼吸，）“正常”袋通气（4.8L·min 容积，约 400mL 潮气量，12 次/分钟），）袋过度通气（9L·min 容积，约 750mL 潮气量，12 次/分钟），）最大过度通气（15L·min 容积，约 750mL 潮气量，20 次/分钟）或）机械通气。然后猪恢复意识并恢复 24 小时，随后安乐死并收集血液和组织样本。没有任何一种手动通气水平对血流动力学变量有任何显著影响。除了白细胞介素-1β的短暂增加外，组织损伤和血浆细胞因子的血液标志物在各组之间没有统计学差异；所有值在 24 小时内均恢复到基线。病理检查结果显示，各组间肺水肿或其他大体病理学的严重程度和分布没有显著差异。这些数据表明，过度通气不会产生不利影响，包括炎症和组织损伤，并且在创伤护理的院前阶段可能会出现的急性过度通气不会在中度出血后导致肺部出现不良影响的证据。适当的气道管理对创伤和危重症患者至关重要。长时间的机械通气会导致过度通气引起的肺气压伤，但很少有研究探讨急性过度通气的后果。我们研究了猪在出血后 1 小时过度通气的结果。我们发现，在创伤护理的院前阶段可能会出现的急性过度通气不会导致中度出血后健康肺出现不良影响的证据。
