Beneficial effect of N-acetyl-cysteine on renal injury triggered by ischemia and reperfusion.

Reactive oxygen species are critical mediators of the early phase of ischemic (IR) injury. The contribution of antioxidants, such as N-acetyl-cysteine (NAC), in ameliorating the parenchymal lesions, inflammatory parameters, and functional variables in renal IR is still controversial. We studied the effect of NAC administration on renal injury induced by IR. Mice were subjected to renal pedicle occlusion and subsequent reperfusion for 24 or 120 hours. NAC was administered prior to surgery at two concentrations (40 or 300 mg/kg, i.p.). Renal function and acute tubular necrosis were assessed, as well as immune phenotyping of infiltrating cells, by flow cytometry. At 40 mg/dL of NAC, we did not observe any significant improvement in renal function (1.85 +/- 0.43 md/dL, P = .367) or tissue architecture (% of ATN: 2.51 +/- 0.27 mm, P = .852) compared to the controls (1.87 +/- 0.43 mg/dL and 3.12 +/- 0.34 mm, respectively). However, animals that received 300 mg/dL of NAC showed lower serum creatinine values (24 hours: 1.25 +/- 0.54 mg/dL) compared to controls (P = .009) and less extensive acute tubular necrosis (1.54 +/- 0.12 vs, P < .05). Treatment with 300 mg/dL of NAC decreased renal dendritic cell infiltration. The protective effect of NAC was better observed at high concentrations and early times.

[Value of preoperative blood coagulation analysis for assessment of hemorrhage risk in general surgery]. / Die Bedeutung der präoperativen Gerinnungsanalytik für die Einschätzung des Blutungsrisikos in der Allgemeinchirurgie.

Coagulation studies, i.e. platelet count, prothrombin time (PT) and activated partial thrombin time (aPTT) are commonly employed preoperatively to identify patients at risk. In a retrospective study we evaluated the usefulness of these screening tests to predict postoperative bleeding in 1447 patients with abdominal and thoracic surgery. Forty-six patients (3.2%) experienced postsurgical bleeding. 12.2% of our patients had abnormal coagulation studies. The sensitivity of abnormal coagulation studies with respect to postoperative bleeding was 23.9%. The sensitivity of the parameter "patient at risk", i.e. patients with suspected coagulopathies due to drugs or disease of the liver or kidney, was 56.5%. Thirty-four out of 1008 patients without risk factors had abnormal coagulation tests but an uneventful postoperative course. Preoperative screening of PT and aPTT should be reserved for patients with known or suspected inherited or acquired coagulopathies.

[Not Available]. / Die Bedeutung der präoperativen Gerinnungsanalytik für die Einschätzung des Blutungsrisikos in der Allgemeinchirurgie.

Coagulation studies, i. e. platelet count, prothrombin time (PT) and activated partial thrombin time (aPTT) are commonly employed preoperatively to identify patients at risk. In a retrospective study we evaluated the usefulness of these screening tests to predict postoperative bleeding in 1447 patients with abdominal and thoracic surgery. Forty-six patients (3.2 %) experienced postsurgical bleeding. 12.2 % of our patients had abnormal coagulation studies. The sensitivity of abnormal coagulation studies with respect to postoperative bleeding was 23.9 %. The sensitivity of the parameter "patient at risk", i. e. patients with suspected coagulopathies due to drugs or disease of the liver or kidney, was 56.5 %. Thirty-four out of 1008 patients without risk factors had abnormal coagulation tests but an uneventful postoperative course. Preoperative screening of PT and aPTT should be reserved for patients with known or suspected inherited or acquired coagulopathies.