Knudson M M, Bermudez K M, Doyle C A, Mackersie R C, Hopf H W, Morabito D
Department of Surgery, University of California, San Francisco, USA.
J Trauma. 1997 Apr;42(4):608-14; discussion 614-6. doi: 10.1097/00005373-199704000-00005.
Tissue oxygen tension can be measured directly in selected organ beds, and these measurements may be more sensitive in assessing the adequacy of resuscitation than global physiologic parameters. We hypothesized that heart tissue oxygen tension would be an important marker for the severity of ischemic insult to the heart during hemorrhagic shock. We further hypothesized that gut oxygen tension measured in the jejunum would prove to be a better measure of splanchnic hypoperfusion than intramucosal pH (pHi).
Tissue oxygen probes were inserted directly into the myocardium of the left ventricle and into the lumen of the proximal jejunum in 10 anesthetized swine. A pHi catheter was introduced into the stomach. The animals were subjected to a controlled hemorrhage of 50% of estimated blood volume. Gut and cardiac oxygen were monitored continuously during hemorrhage and resuscitation, which was performed with shed blood and crystalloid.
While gut O2 and pHi trended together, we were unable to establish a correlation between changes in these two variables during hemorrhage and resuscitation. Heart PO2 decreased significantly during hemorrhage, but surpassed baseline values after resuscitation, a finding not seen in gut PO2. No standard physiologic variables reliably predicted changes in heart PO2 during these experiments.
Tissue oxygen tensions measurements are highly responsive to changes induced during graded hemorrhagic shock and resuscitation. Gut PO2 and pHi appear to be measuring different physiologic processes in the gastrointestinal tract. The compensatory ability of the heart far exceeds that of the gut after ischemic insult. This hemorrhagic shock model appears feasible for the study of various methods of resuscitation.
组织氧分压可在特定器官床直接测量，这些测量在评估复苏的充分性方面可能比整体生理参数更敏感。我们假设心脏组织氧分压将是失血性休克期间心脏缺血损伤严重程度的重要标志物。我们进一步假设，在空肠中测量的肠道氧分压将被证明是比黏膜内pH值（pHi）更好的内脏低灌注指标。
将组织氧探头直接插入10只麻醉猪的左心室心肌和空肠近端肠腔。将一根pHi导管插入胃中。使动物控制性失血50%估计血容量。在出血和复苏过程中持续监测肠道和心脏的氧情况，复苏采用自体血和晶体液。
虽然肠道氧和pHi呈共同趋势，但我们无法在出血和复苏期间建立这两个变量变化之间的相关性。出血期间心脏的氧分压显著下降，但复苏后超过基线值，这一发现未见于肠道氧分压。在这些实验中，没有标准生理变量能可靠地预测心脏氧分压的变化。
组织氧分压测量对分级失血性休克和复苏期间引起的变化高度敏感。肠道氧分压和pHi似乎在测量胃肠道不同的生理过程。缺血损伤后心脏的代偿能力远超过肠道。这个失血性休克模型似乎对于研究各种复苏方法是可行的。
