To investigate the mechanism by which pneumothorax may occur as a complication of tracheal intubation, we submitted four cats to tracheotomy and three to tracheal intubation. To simulate the dissection of air along fascial planes following tracheotomy, we placed catheters in either the pretracheal or subcutaneous plane and applied positive pressure to the catheters. The cats undergoing tracheal intubation were ventilated with excessive positive pressure. Computed tomography was used to document the progression of pneumothorax. High positive pressures during mechanical ventilation led to pneumothorax and pneumomediastinum, and the mechanism was primarily the dissection of air along the perivascular sheaths of the pulmonary arteries, presumably due to rupture of perivascular alveoli. Dissection of air along the pretracheal fascia following tracheotomy produced pneumomediastinum but not pneumothorax. This suggests that pneumothorax occurring clinically is more likely a complication of assisted ventilation than a complication of tracheotomy surgery.

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Portugal is half way between countries with the highest and lowest IBD prevalence, but is steeply making the road to the highest-level group. Despite limitations of the proposed methods, assumptions were reasonable and estimates seem to be valid. Feasibility and comparability of this methodology makes it an interesting tool for future studies on IBD epidemiology.

Background. The shortage of kidneys available for transplantation has led to enlarged criteria donors (ECD): namely, donors older than 60 years or aged between 50 and 59 years with 2 of the following characteristics-hypertension, predonation serum creatinine level higher than 1.5 mg/dL or cerebrovascular disease as the cause of death. The aim of this study was to analyze renal transplants using ECD compared with standard criteria donors (SCD) concerning the incidences of delayed graft function (DGF), acute rejection episodes (ARE), and patient and graft survivals. Materials and Methods. This retrospective study of 409 cadaveric renal transplants over the last 4 years identified ECD in contrast with SCD. Results. Of the transplants, 24.4% used ECD. The baseline characteristics of recipients of ECD versus SCD kidneys were similar, except for age and cold ischemia time.Comparing ECD and SCD, we observed an higher incidence of DGF (35% vs 18%), occurrence of ARE (34.4% vs 16.6%), average serum creatinine levels at 6 (1.87 vs 1.4 mg/dL), and 12 months (1.88 vs 1.43 mg/dL) as well as lower graft survival at 1 (82% vs 91%) and 3 years (75% vs 84%) after transplantation. Recipient survival at 1 year was not different. Multivariate analysis identified recipient age, cold ischemia time, ARE, and DGF as risk factors for graft failure. Conclusions. Renal transplantation with grafts from ECD shows significantly worse outcomes with higher rates of DGF and ARE, worse graft function, and lower graft survival.

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