A disadvantage of nonradioactive microsphere techniques is that the processing of samples is time-consuming and complex. We developed and validated a simplified processing method for the fluorescent microsphere (FM) technique. In seven anesthetized dogs with coronary artery stenosis up to six different FM and five different radioactivity labeled microspheres (RM) were injected. Two FM and two RM labels were injected simultaneously to enable inter- and intramethod comparison. After gamma-counting samples of blood, myocardium (n = 168), and other organs (n = 59) were digested in test tubes with 2 N ethanolic KOH (60 degrees C, 48 h), microspheres were sedimented by centrifugation, dye was extracted in the same tube, and fluorescence was measured. With this processing method, recovery of FM was approximately 100%. Good correlations for inter- and intramethod comparisons were found [r = 0.985 +/- 0.01 (mean +/- SD)]. The lower intermethod correlation for blue microspheres (r = 0.958) indicates that the use of this label is less desirable. RM and FM endocardial-to-epicardial blood flow ratios correlated well (r = 0.974). With this one-vessel centrifugal sedimentation method and at least five fluorescently labeled microspheres, blood flow can be reliably measured in various organs, including ischemic myocardium.
BackgroundGut barrier loss has been implicated as a critical event in the occurrence of postoperative complications. We aimed to study the development of gut barrier loss in patients undergoing major non-abdominal surgery.Methodology/Principal FindingsTwenty consecutive children undergoing spinal fusion surgery were included. This kind of surgery is characterized by long operation time, significant blood loss, prolonged systemic hypotension, without directly leading to compromise of the intestines by intestinal manipulation or use of extracorporeal circulation. Blood was collected preoperatively, every two hours during surgery and 2, 4, 15 and 24 hours postoperatively. Gut mucosal barrier was assessed by plasma markers for enterocyte damage (I-FABP, I-BABP) and urinary presence of tight junction protein claudin-3. Intestinal mucosal perfusion was measured by gastric tonometry (PrCO2, Pr-aCO2-gap). Plasma concentration of I-FABP, I-BABP and urinary expression of claudin-3 increased rapidly and significantly after the onset of surgery in most children. Postoperatively, all markers decreased promptly towards baseline values together with normalisation of MAP. Plasma levels of I-FABP, I-BABP were significantly negatively correlated with MAP at ½ hour before blood sampling (−0.726 (p<0.001), −0.483 (P<0.001), respectively). Furthermore, circulating I-FABP correlated with gastric mucosal PrCO2, Pr-aCO2-gap measured at the same time points (0.553 (p = 0.040), 0.585 (p = 0.028), respectively).Conclusions/SignificanceThis study shows the development of gut barrier loss in children undergoing major non-abdominal surgery, which is related to preceding hypotension and mesenterial hypoperfusion. These data shed new light on the potential role of peroperative circulatory perturbation and intestinal barrier loss.
Dexmedetomidine decreases plasma catecholamines and heart rate during emergence from anesthesia. In dogs with a coronary stenosis, these sympatholytic effects decrease myocardial lactate release and, therefore, minimize emergence-related myocardial ischemia.
Doppler-guided GDFT during and in the first hours after elective colorectal surgery for malignancy increases global gastrointestinal perfusion, as measured by P CO -gap.
SummaryThe blood coagulating factors II and VII and prothrombin times (Thrombotest) were followed during a dosage interval (= 24 h) in patients on acenocoumarol (n = 6) and on phenprocoumon (n = 6) therapy. The patients were on stable anti-coagulation (%TT: 7-13%) for at least 6 months. The study was performed to investigate the concentration-response relationship of the 4-hydroxycoumarin-type oral anticoagulants. The three parameters were stable during the 24-h interval for patients on phenprocoumon therapy. Patients on acenoumarol showed fluctuations in their factor VII levels; peak activities were observed at about 2 h, trough activities at about 16 h after acenocoumarol intake. Factor II and Thrombotest activities were stable. Plasma levels of phenprocoumon were stable during daytime whereas acenocoumarol levels declined exponentially (t½ about 12 h). The results indicate the oral anticoagulants to exhibit a concentration-response relationship common to drug-receptor interactions. The results also suggest that for stable and long-lasting anticoagulant therapy oral anticoagulants with half-lives beyond the dosage interval (t½>24 h) should be preferred.
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