Benjamin E, Paluch T A, Berger S R, Premus G, Wu C, Iberti T J
Crit Care Med. 1987 May;15(5):516-8. doi: 10.1097/00003246-198705000-00013.
The venous-arterial PCO2 gradient may increase in certain low-flow states, such as CPR and canine endotoxemia. To determine whether venous hypercarbia also occurs in hemorrhagic shock, we studied 12 anesthetized, mechanically ventilated dogs. We performed laparotomies on the animals, inserting catheters into their renal, superior mesenteric, and external iliac veins. Flow in the corresponding arteries were determined using electromagnetic flow probes. The dogs were randomized into a control group (n = 6), and a hemorrhagic shock group (n = 6) which was bled to a mean arterial pressure of 45 to 50 mm Hg and maintained at this pressure for the 6-h study. The results demonstrated a significant (p less than .05) increase in lactate and venous-arterial PCO2 gradient systemically and in all three regional beds. A significant decrease of venous blood pH accompanied these changes which are consistent with our previous findings in low-flow, canine endotoxemia. We conclude that venous hypercarbia is a nonspecific phenomenon, common to low-flow states. The increased CO2 represents both an increased CO2 production and a decreased removal, secondary to low-flow.
在某些低血流状态下，如心肺复苏和犬类内毒素血症时，静脉 - 动脉血二氧化碳分压差可能会增加。为了确定失血性休克时是否也会出现静脉血高碳酸血症，我们对12只麻醉、机械通气的犬进行了研究。我们对这些动物进行剖腹手术，将导管插入其肾静脉、肠系膜上静脉和髂外静脉。使用电磁流量探头测定相应动脉中的血流。将犬随机分为对照组（n = 6）和失血性休克组（n = 6），失血性休克组动物放血至平均动脉压为45至50 mmHg，并在该压力下维持6小时进行研究。结果表明，全身及所有三个局部区域的乳酸和静脉 - 动脉血二氧化碳分压差均显著（p < 0.05）升高。伴随着这些变化，静脉血pH值显著降低，这与我们之前在低血流犬类内毒素血症中的发现一致。我们得出结论，静脉血高碳酸血症是一种非特异性现象，常见于低血流状态。二氧化碳增加既代表二氧化碳生成增加，也代表由于低血流导致的清除减少。
