Department of Respiratory Medicine, East Hospital, Tongji University School of Medicine, Shanghai 200120, China (Guo ZL, Ren T, Liang YJ); Pediatric Department, Zhongshan Hospital, Fudan University, Shanghai 200032, China (Cai YY); Pediatric ICU, Pediatrics Hospital, Fudan University, Shanghai 200032, China (Lu GP, Gong JY).
World J Emerg Med. 2010;1(1):59-64.
Low tidal volume mechanical ventilation is difficult to correct hypoxemia, and prolonged inhalation of pure oxygen can lead to oxygen poisoning. We suggest that continuous tracheal gas insufflation (TGI) during protective mechanical ventilation could improve cardiopulmonary function in acute lung injury.
Totally 12 healthy juvenile piglets were anesthetized and mechanically ventilated at PEEP of 2 cmH2O with a peak inspiratory pressure of 10 cmH2O. The piglets were challenged with lipopolysaccharide and randomly assigned into two groups (n=6 each group): mechanical ventilation (MV) alone and TGI with continuous airway flow 2 l/min. FIO2 was set at 0.4 to avoid oxygen toxicity and continuously monitored with an oxygen analyzer.
Tidal volume, ventilation efficacy index and mean airway resistant pressure were significantly improved in the TGI group (P<0.01 or P<0.05). At 4 hours post ALI, pH decreased to below 7.20 in the MV group, and improved in the TGI group (P<0.01). Similarly, PaCO2 was stable and was significantly lower in the TGI group than in the MV group (P<0.01). PaO2 and PaO2/FIO2 increased also in the TGI group (P<0.05). There was no significant difference in heart rate, respiratory rate, mean artery pressure, central venous pressure, dynamic lung compliance and mean resistance of airway between the two groups. Lung histological examination showed reduced inflammation, reduced intra-alveolar and interstitial patchy hemorrhage, and homogenously expanded lungs in the TGI group.
Continuous TGI during MV can significantly improve gas exchange and ventilation efficacy and may provide a better treatment for acute lung injury.
低潮气量机械通气难以纠正低氧血症，长时间吸入纯氧可导致氧中毒。我们建议，在保护性机械通气期间持续进行经气管气体注入（TGI）可改善急性肺损伤的心肺功能。
12 只健康幼年猪在呼气末正压 2 cmH2O、吸气峰压 10 cmH2O 下接受机械通气，并给予脂多糖刺激，然后随机分为两组（每组 6 只）：单独机械通气（MV）组和 TGI 组（持续气道气流 2 l/min）。FIO2 设定为 0.4 以避免氧中毒，并使用氧气分析仪连续监测。
TGI 组的潮气量、通气效率指数和平均气道阻力明显改善（P<0.01 或 P<0.05）。在急性肺损伤后 4 小时，MV 组的 pH 值降至 7.20 以下，而 TGI 组则有所改善（P<0.01）。同样，PaCO2 在 TGI 组保持稳定且明显低于 MV 组（P<0.01）。PaO2 和 PaO2/FIO2 在 TGI 组也有所增加（P<0.05）。两组间心率、呼吸频率、平均动脉压、中心静脉压、动态肺顺应性和气道平均阻力无显著差异。肺组织学检查显示，TGI 组炎症减轻，肺泡和间质斑片状出血减少，肺均匀扩张。
在 MV 期间持续进行 TGI 可显著改善气体交换和通气效率，可能为急性肺损伤提供更好的治疗方法。
