Second Department of Critical Care Medicine, Attiko University Hospital, Medical School, National and Kapodistrian University of Athens, 1 Rimini Street, Haidari, 12462, Athens, Greece.
Intensive Care Med. 2011 Nov;37(11):1756-64. doi: 10.1007/s00134-011-2336-8. Epub 2011 Aug 17.
More than a disorder of macrocirculation, sepsis is a disease affecting the microcirculation and the tissue metabolism. In vivo microdialysis (MD) is a bedside technique that can monitor tissue metabolic changes. We conducted this study aiming (1) to assess whether patients at different sepsis stages present with different MD-assessed tissue metabolic profiles and (2) to determine if different underlying types of infections and implicated pathogens are associated with dissimilar metabolic alterations.
We studied 90 mechanically ventilated patients, 65 with septic shock and 25 with severe sepsis. An MD catheter was inserted in the subcutaneous adipose tissue of the upper thigh and interstitial fluid samples were collected along with arterial blood samples every 4 h for a maximum of 6 days. Lactate, pyruvate, glycerol, and glucose concentrations were measured.
During the study period, patients with septic shock had higher MD-assessed glycerol (P = 0.009), glycerol gradient (P = 0.016), and glucose (P = 0.004) than patients with severe sepsis, whereas tissue lactate, lactate gradient, and pyruvate dropped significantly with time (P = 0.007, <0.001, and <0.001, respectively) in both patient groups without any observed between-group difference. In addition, there was no between-group difference in their tissue lactate/pyruvate ratio on any day, nor did the ratio decrease significantly with time. Compared with pneumonia patients, and despite similar baseline clinical characteristics, those suffering from intra-abdominal infections showed a pattern of higher and progressively increasing tissue levels of glucose (P = 0.001) and glycerol (P = 0.001). Finally, patients harboring gram-positive infections had higher tissue levels of glycerol (P = 0.027) and glycerol gradient (P = 0.029) than patients with gram-negative infections.
MD can detect tissue metabolic abnormalities that differ in relation to the sepsis stage and the type of underlying infection or responsible pathogen. Some of the MD-assessed abnormalities are not reflected by conventional blood measurements and possess prognostic potential. It remains to be determined if this type of metabolic monitoring can find clinical applications in the wide population of septic critically ill patients.
败血症不仅是一种大循环紊乱的疾病，它还会影响微循环和组织代谢。在体微透析（MD）是一种床边技术，可以监测组织代谢变化。我们进行这项研究旨在（1）评估不同败血症阶段的患者是否存在不同的 MD 评估组织代谢谱，以及（2）确定不同潜在感染类型和相关病原体是否与不同的代谢改变相关。
我们研究了 90 名机械通气患者，其中 65 名患有感染性休克，25 名患有严重败血症。在大腿的皮下脂肪组织中插入 MD 导管，并在 6 天内每隔 4 小时采集间质液样本和动脉血样本。测量乳酸、丙酮酸、甘油和葡萄糖浓度。
在研究期间，感染性休克患者的 MD 评估甘油（P = 0.009）、甘油梯度（P = 0.016）和葡萄糖（P = 0.004）均高于严重败血症患者，而两组患者的组织乳酸、乳酸梯度和丙酮酸随时间显著下降（P = 0.007，<0.001 和<0.001），但两组之间没有观察到差异。此外，两组患者在任何一天的组织乳酸/丙酮酸比值均无差异，且比值随时间无明显下降。与肺炎患者相比，尽管基线临床特征相似，但患有腹腔内感染的患者表现出组织葡萄糖（P = 0.001）和甘油（P = 0.001）水平升高且逐渐升高的模式。最后，革兰氏阳性感染患者的组织甘油（P = 0.027）和甘油梯度（P = 0.029）水平高于革兰氏阴性感染患者。
MD 可以检测到与败血症阶段和潜在感染类型或致病病原体相关的不同组织代谢异常。一些 MD 评估的异常不受常规血液测量的影响，具有预后潜力。仍需确定这种代谢监测是否可以在广泛的败血症危重患者人群中找到临床应用。
