Department of Experimental Medicine (FEM), Charité-University Medicine Berlin, Berlin, Germany.
Artif Organs. 2013 Dec;37(12):1049-58. doi: 10.1111/aor.12104. Epub 2013 Jun 5.
Experimental data indicate that hypercapnic adidosis has anti-inflammatory effects. These anti-inflammatory effects may even be a beneficial property in case of low tidal volume ventilation with consecutive hypercapnic acidosis. It is unclear whether these anti-inflammatory effects predominate in critically ill patients who suffer from multiple pro- and anti-inflammatory insults like extracorporeal organ support (pro-inflammatory), metabolic acidosis (pro- and anti-inflammatory), as well as hypoxia (pro-inflammatory). Eighteen pigs were randomized into three groups, mechanically ventilated and connected to a continuous veno-venous hemofiltration (CVVH) as pro-inflammatory insult. A reference group with normal acid-base state obtained normoventilation; a normoxemic acidemia group obtained normoxemic, mixed acidemia due to infusion of lactic and hyperchloremic acid and low tidal volume ventilation, and in a hypoxemic acidemia group the mixed acidemia was paralleled by hypoxemia. Lung histology including pulmonary leukocyte invasion, blood gases, blood cell counts, and hemodynamics were examined. The histological examination of the lungs of acidemic pigs showed a suppressed invasion of leukocytes and thinner alveolar walls compared with normoventilated and with hypoxemic pigs. Enhanced congestion and alveolar red blood cells (RBCs) combined with an increase of the pulmonary artery pressure were observed in acidemic pigs in comparison with the reference group. Normoxemic acidemia reduced the pro-inflammatory reaction to the CVVH and mechanical ventilation in the ventilated lung areas in the form of pulmonary leukocyte invasion. However, this did not result in reduced scores for lung injury. Instead, an increased score for criteria which represent lung injury (congestion and alveolar RBCs) was observed in acidemic pigs.
实验数据表明，高碳酸血症性酸中毒具有抗炎作用。这些抗炎作用在低潮气量通气伴随后续高碳酸性酸中毒的情况下甚至可能是有益的特性。目前尚不清楚这些抗炎作用是否在患有多种促炎和抗炎性损伤的危重病患者中占主导地位，例如体外器官支持（促炎）、代谢性酸中毒（促炎和抗炎）以及缺氧（促炎）。18 头猪随机分为三组，进行机械通气并连接连续静脉-静脉血液滤过（CVVH）以进行炎症刺激。参考组为酸碱状态正常，接受正常通气；正常氧合性酸中毒组接受正常氧合、混合性酸中毒，原因是输注乳酸和高氯酸盐以及低潮气量通气，而低氧合性酸中毒组的混合性酸中毒伴有低氧血症。检查肺组织学包括肺白细胞浸润、血气、血细胞计数和血液动力学。与正常通气和低氧血症猪相比，酸性猪的肺部组织学检查显示白细胞浸润减少，肺泡壁变薄。与参考组相比，酸性猪观察到充血增强和肺泡红细胞（RBC）增加，同时肺动脉压升高。与机械通气和 CVVH 相关的促炎反应在正常氧合性酸中毒组中减轻了通气肺区的炎症。然而，这并没有导致肺损伤评分降低。相反，在酸性猪中观察到代表肺损伤的标准（充血和肺泡 RBC）的评分增加。
