Yanos J, Presberg K, Crawford G, Meller J, Wood L D, Sznajder J I
University of Pittsburgh, Montefiore Hospital, Pennsylvania 15213.
Am Rev Respir Dis. 1990 Aug;142(2):316-20. doi: 10.1164/ajrccm/142.2.316.
The effects of the mechanical factors involved in ventilation on pulmonary edema are only partially understood. To clarify the effect of ventilation on the adult respiratory distress syndrome (ARDS), we examined the effect of reducing rate and tidal volume on oleic acid-induced low-pressure pulmonary edema in dogs, hypothesizing that hypopnea would reduce lung edema. We placed the experimental animals on venous-venous extracorporeal membrane oxygenation (ECMO) for CO2 clearance and oxygenation 1 h after the injury. This allowed reduction of the ventilatory rate from 17.2 +/- 4.8 to 3.3 +/- 0.8 breaths/min and tidal volume from 20 to 16 ml/kg, effectively resting the injured lung. After 5 h of hypopnea there was no reduction in edema by gravimetric or extravascular thermal volume measurements. The ECMO-facilitated hypopnea reduced airway pressure and pulmonary artery pressure while improving arterial oxygen saturation but increased venous admixture. These results suggest that there may be a supportive role for ECMO-assisted hypopnea, but there was no direct beneficial effect of hypopnea on edema.
通气过程中涉及的机械因素对肺水肿的影响仅得到部分理解。为阐明通气对成人呼吸窘迫综合征（ARDS）的影响，我们研究了降低呼吸频率和潮气量对油酸诱导的犬低压性肺水肿的作用，假设呼吸浅慢会减轻肺水肿。在损伤后1小时，我们将实验动物置于静脉-静脉体外膜肺氧合（ECMO）上以清除二氧化碳并进行氧合。这使得呼吸频率从17.2±4.8次/分钟降至3.3±0.8次/分钟，潮气量从20ml/kg降至16ml/kg，从而有效减轻受伤肺的负担。呼吸浅慢5小时后，通过重量法或血管外热容积测量发现肺水肿并未减轻。ECMO辅助的呼吸浅慢降低了气道压力和肺动脉压力，同时提高了动脉血氧饱和度，但增加了静脉混合血。这些结果表明，ECMO辅助的呼吸浅慢可能具有支持作用，但呼吸浅慢对肺水肿没有直接的有益影响。
