Intramucosal pH measurement with tonometers for detecting gastrointestinal ischemia in critically ill patients

为明确胃压计作为内脏器官组织氧合充分性监测的有效性，对38例合并多发伤(10例)、烧伤(5例)、大手术(18例)和脓毒症(5例)的危重患者进行了粘膜内pH值(Phi)的测定。结果如下：1.休克后代偿期或术后即刻PHI值降至7.3以下，但多数患者在伤后72小时内恢复到7.3或以上。2.15例创伤休克患者伤后72小时血pH与乳酸、IL-6、动脉血酮体比、中性粒细胞弹性蛋白酶、纤溶酶原激活物抑制物-1呈显著正相关。损伤程度与PHI值有密切关系。3.应用Swan-Ganz导尿管计算的DO2和适当的VO2超正常化后，PHI值降低。常规方法不能评估高动力状态患者胃粘膜氧合的充分性，因此，胃粘膜内pH值的测定是预测肠系膜低灌注的新指标。4.为了克服组织氧合不足的问题，我们检测了多巴胺或前列腺素E_1等血管扩张剂的作用，后者有效地改善了胃液的pH值。5.胃液pH值与胃液pH值呈显著正相关，因此，可能需要给予组胺-2受体拮抗剂以获得PH值的重复性。本研究的结果表明，粘膜内pH的测量提供了术后或损伤后阶段以及脓毒症患者组织氧合充分性的代谢指标。需要进一步的研究来阐明如何在粘膜代谢中提高氧摄取率的机制。

To clarify an availability of gastric tonometer as a moniter for adequacy of tissue oxygenation in the splanchnic organs, intramucosal pH (pHi) was measured in 38 critically ill patients with multiple trauma (10), burn (5), major surgery (18) and sepsis (5). The results were as follows ;1.The value of pHi was reduced to less than 7.3 at the compansated state from shock or at the immediate postoperative period, but most patients recovered to the level of 7.3 or more within the first 72 hours postinjury. The pHi value in two cases persisted less than 7.3 over 72 hours postinjury with fatal outcome.2.Significant correlations were observed among pHi and lactate, IL-6, arterial keton body ratio, nutrophil elastase and plasminogen activator inhibitor-1 in 15 patients with trauma shock after the first 72 hours postinjury. A close relationship was admitted between the degree of insult and the value of pHi.3.The value of pHi was reduced despite of supranormalisation of Do2 and adequate Vo2 calculated with Swan-Ganz catheter. The adequacy of mucosal oxygenation in hyperdymamic state of patients was not assessed with the conventional method, therefore, measuring intramucosal pH in the stomach is a new predictor of development of mesenteric hypoperfusion.4.To overcome the inadequacy of tissue oxygenation, the effect of the vasodilators such as Dopamine or PGE1 were tested and the latter was effective on improving of the pHi value.5.A significant correlation was seen between pH of gastric juice and the value of pHi, therefore, the administration of a histamine-2 receptor antagonist may be required to get the reproducibility of pHi.The results of this study indicated that measurements of intramucosal pH provide a metabolic measure of the adequacy of tissue oxygenation in the postoperative or postinjury phase as well as in septic patients.Further studies are needed to eludcidate the mechanism about how oxygen extraction rate can be improved in mucosal metahbolism.