Gattinoni Luciano
Department of Anesthesiology, Emergency and Intensive Care Medicine, Georg-August-University of Göttingen, Göttingen, Germany.
Crit Care. 2016 May 12;20(1):130. doi: 10.1186/s13054-016-1310-9.
Partial extracorporeal CO2 removal allows a decreasing tidal volume without respiratory acidosis in patients with acute respiratory distress syndrome. This, however, may be associated with worsening hypoxemia, due to several mechanisms, such as gravitational and reabsorption atelectasis, due to a decrease in mean airway pressure and a critically low ventilation-perfusion ratio, respectively. In addition, an imbalance between alveolar and artificial lung partial pressures of nitrogen may accelerate the process. Finally, the decrease in the respiratory quotient, leading to unrecognized alveolar hypoxia and monotonous low plateau pressures preventing critical opening, may contribute to hypoxemia.
对于急性呼吸窘迫综合征患者，部分体外二氧化碳清除可在不发生呼吸性酸中毒的情况下降低潮气量。然而，这可能与低氧血症加重有关，其机制有多种，比如分别由于平均气道压降低和通气/血流比极低导致的重力性肺不张和再吸收性肺不张。此外，肺泡与人工肺之间氮气分压的失衡可能会加速这一过程。最后，呼吸商降低导致未被识别的肺泡低氧以及单调的低平台压阻碍关键开口，可能会导致低氧血症。
