Black Ian H, Angelucci Michael P, Linfoot John A, Grathwohl Kurt W
Brooke Army Medical Center), Consortium, San Antonio, Texas, USA.
J Trauma. 2008 Nov;65(5):1133-9. doi: 10.1097/TA.0b013e318166d262.
Mechanical ventilation of intubated patients is standard to meet oxygenation and ventilation goals. This can require significant energy and oxygen resources. In military operations and mass casualty disasters, oxygen conserving strategies may be important. Low flow tracheal insufflation of oxygen (TRIO) is a technique that provides adequate oxygenation while conserving oxygen during apnea. This technique, however, is limited by increases in carbon dioxide (CO2) when used for extended periods. The addition of passive pressure release ventilation could potentially improve CO2 elimination and the acceptance of this technique. The purpose of this study was to determine whether TRIO combined with the novel configuration of a portable ventilator used to provide passive pressure release ventilation improves CO2 levels during apneic oxygenation.
Animals (n = 7) were anesthetized, paralyzed, and intubated. Oxygen (O2) was insufflated through the capillary lumen of the Boussignac endotracheal tube at 2 L/min. The low flow O2 was the only source of power and gas for ventilation. A modified Oxylator EMX transport ventilator connected to the endotracheal tube was configured to release when pressure in the subjects lungs reached 30 cm H2O. No electrical or pneumatic sources were required. Hemodynamic measurements and arterial blood gases were taken at various intervals for 2 hours.
All pigs remained adequately oxygenated with Pao2 >390 mm Hg in all subjects at every blood gas measurement and survived the 2-hour experiment. Baseline Paco2 (43 +/- 4 mm Hg) increased and pH (7.48 +/- 0.03) decreased to 72 +/- 5 mm Hg and 7.29 +/- 0.02 at 1 hour and 83 +/- 8, 7.24 +/- 0.03 at 2 hours. This is significantly less than would be expected during apnea over this time period. Hemodynamic measurements remained stable.
The combination of low flow TRIO with a modified Oxylator in this novel configuration provides acceptable Pao2, Paco2, and hemodynamic parameters for 2 hours in apneic swine. This could be a valuable technique in situations where oxygen and power are limited.
对插管患者进行机械通气是实现氧合和通气目标的标准方法。这可能需要大量的能量和氧气资源。在军事行动和大规模伤亡灾难中，氧节约策略可能很重要。低流量气管内充氧（TRIO）是一种在呼吸暂停期间既能提供充足氧合又能节约氧气的技术。然而，该技术在长时间使用时会受到二氧化碳（CO₂）增加的限制。添加被动压力释放通气可能会改善CO₂的排出并提高该技术的可接受性。本研究的目的是确定TRIO与用于提供被动压力释放通气的新型便携式呼吸机配置相结合是否能在呼吸暂停氧合期间改善CO₂水平。
对7只动物进行麻醉、麻痹并插管。通过Boussignac气管导管的毛细管腔以2 L/min的速度充入氧气（O₂）。低流量O₂是通气的唯一动力和气体来源。连接到气管导管的改良型Oxylator EMX转运呼吸机被配置为当受试者肺部压力达到30 cm H₂O时释放。无需电力或气动源。在2小时内的不同时间间隔进行血流动力学测量和动脉血气分析。
在每次血气测量时，所有猪的氧合均保持良好，所有受试者的动脉血氧分压（Pao₂）>390 mm Hg，并在2小时的实验中存活。基线动脉血二氧化碳分压（Paco₂）（43±4 mm Hg）在1小时时升高至72±5 mm Hg，pH（7.48±0.03）降至7.29±0.02，在2小时时分别为83±8 mm Hg和7.24±0.03。这明显低于该时间段呼吸暂停时的预期值。血流动力学测量保持稳定。
在这种新型配置中，低流量TRIO与改良型Oxylator相结合，在呼吸暂停的猪中2小时内提供了可接受的Pao₂、Paco₂和血流动力学参数。在氧气和动力有限的情况下，这可能是一种有价值的技术。
