Hummler H D, Schulze A, Pohlandt F, Thome U
Division of Neonatology and Pediatric Critical Care, Children's Hospital, University of Ulm, Germany.
Pediatr Res. 2000 Mar;47(3):392-7. doi: 10.1203/00006450-200003000-00018.
Partial liquid ventilation (PLV) has been shown to improve gas exchange in paralyzed animals and in humans with lung disease. This study tests the hypothesis that PLV combined with respiratory mechanical unloading results in stable ventilation and gas exchange in spontaneously breathing animals. Ten adult anesthetized, intubated, and spontaneously breathing rabbits received ventilatory support by respiratory mechanical unloading (Fi(O2) 1.0). Minute ventilation, respiratory rate, esophageal pressure, heart rate, and arterial blood pressure were recorded continuously during gas ventilation for 1 h. Next, 30 mL/kg of perfluorocarbon was instilled into the endotracheal tube. Thereafter, data were recorded again for 1 h (PLV). Arterial blood gases were obtained at the end of each period. Variability of recorded data was assessed by calculating coefficients of variation using data obtained each minute. Compared with gas ventilation, minute ventilation was larger during PLV (275 +/- 93 versus 368 +/- 89 mL/kg/min.; p < 0.01). This was because of a higher respiratory rate during PLV (58 +/- 23 versus 74 +/- 18 breaths/min; p < 0.05), while tidal volume was similar. Compared with gas ventilation, Pa(O2) was lower during PLV (61.31 +/- 5.32 versus 47.35 +/- 8.38 kPa; p < 0.05). Pa(CO2), peak esophageal pressure deflections, heart rate, mean arterial blood pressure, and coefficients of variation for minute ventilation, tidal volume, respiratory rate, and peak esophageal pressure were not significantly different between modes. Compliance was decreased and resistance and work of breathing were increased during PLV. We conclude that stable ventilation and gas exchange may be achieved during PLV combined with mechanical unloading in spontaneously breathing animals without lung disease.
部分液体通气（PLV）已被证明可改善瘫痪动物和患有肺部疾病的人类的气体交换。本研究检验了以下假设：PLV联合呼吸机械卸载可使自主呼吸动物实现稳定的通气和气体交换。十只成年麻醉、插管并自主呼吸的兔子通过呼吸机械卸载（吸入氧分数[Fi(O2)]为1.0）接受通气支持。在气体通气1小时期间持续记录分钟通气量、呼吸频率、食管压力、心率和动脉血压。接下来，将30 mL/kg的全氟化碳注入气管内导管。此后，再次记录数据1小时（PLV）。在每个时间段结束时采集动脉血气。通过使用每分钟获得的数据计算变异系数来评估记录数据的变异性。与气体通气相比，PLV期间分钟通气量更大（275±93对368±89 mL/kg/分钟；p<0.01）。这是因为PLV期间呼吸频率更高（58±23对74±18次/分钟；p<0.05），而潮气量相似。与气体通气相比，PLV期间动脉血氧分压（Pa(O2)）更低（61.31±5.32对47.35±8.38 kPa；p<0.05）。两种模式之间的动脉血二氧化碳分压（Pa(CO2)）、食管压力峰值偏转、心率、平均动脉血压以及分钟通气量、潮气量、呼吸频率和食管压力峰值的变异系数无显著差异。PLV期间顺应性降低，呼吸阻力和呼吸功增加。我们得出结论，在无肺部疾病的自主呼吸动物中，PLV联合机械卸载可实现稳定的通气和气体交换。
