Chest
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Comparative Study
Alveolar epithelial fluid clearance mechanisms are intact after moderate hyperoxic lung injury in rats.
The capacity of the alveolar epithelial barrier to remove excess alveolar fluid from the airspaces of the lung was studied in an experimental model of moderate hyperoxic lung injury. Rats were exposed to 100% oxygen for 40 h in an exposure chamber and compared with control animals exposed to room air. Extravascular lung water was calculated gravimetrically. ⋯ Furthermore, the hyperoxic injured rats responded normally to an exogenous beta-adrenergic agonist (terbutaline, 10(-4) mol/L) with a 67% increase in the rate of alveolar liquid clearance (50 +/- 5%). Thus, in the setting of moderate hyperoxic lung injury, the alveolar epithelial barrier is still capable of removing fluid at a normal rate and responding to beta-adrenergic agonist treatment. These experimental results have potential clinical implications for patients with acute lung injury.
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Aortic root abscess is a common complication of aortic valve endocarditis. However, aortic root abscess and formation of a fistula from the aortic root to the right ventricular outflow tract in the setting of a native aortic valve and previous repair of an aortic dissection with a Dacron graft is an uncommon event. Transesophageal echocardiography is superior to transthoracic echocardiography for the diagnosis of aortic root abscess. To our knowledge, no studies have compared the diagnostic value of cardiac MRI with transesophageal echocardiography for this condition.
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To identify the relative contribution of hydrostatic and permeability mechanisms to the development of human neurogenic pulmonary edema. ⋯ Many of our patients had a hydrostatic mechanism for neurogenic pulmonary edema. This is a novel observation in humans since prior clinical case reports have emphasized increased permeability as the usual mechanism for neurogenic pulmonary edema. These findings are consistent with pulmonary venoconstriction or transient elevation in left-sided cardiovascular pressures as contributing causes to the development of human neurogenic pulmonary edema.
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We hypothesized that the continuous gas flow administration delivered through an insufflation catheter positioned above the carina during airway pressure release ventilation (APRV) would facilitate carbon dioxide (CO2) elimination, resulting in normocarbia with a substantially reduced peak airway pressure (Paw). To test this hypothesis, we compared intermittent positive pressure ventilation (IPPV), tracheal gas insufflation (TGI), APRV, and combined TGI and APRV (TGI + APRV). ⋯ The combined use of TGI and APRV is a more effective method of maintaining normocarbia with reduced peak Paw than either IPPV or APRV alone.
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Comparative Study
Complete lobar collapse following pulmonary lobectomy. Its incidence, predisposing factors, and clinical ramifications.
To define the most severe form of postlobectomy atelectasis and determine its incidence, predisposing factors, and clinical ramifications. ⋯ We conclude that SPLA as defined in this study is an important postoperative complication with a significant incidence. Although patients undergoing right upper lobectomy are markedly predisposed to this problem, the exact pathophysiology remains unclear. Factors shown to be causes of less severe forms of postoperative atelectasis do not seem to contribute to the formation of SPLA, indicating that these two complications may be two unrelated entities.