Chest
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Nasal pressure support ventilation (NPSV) has been shown to be useful in the treatment of acute and chronic pulmonary failure. However, little is known about respiratory muscle activity during NPSV in stable patients with COPD. The aim of this study was to test the effect of two levels (10 and 20 cm H2O) of NPSV on diaphragmatic activity, in a group of seven stable, severe COPD patients (FEV1 20 percent +/- 7 of pred, FEV1/FVC 35 percent) with hypercapnic respiratory insufficiency. ⋯ A marked statistically significant reduction in diaphragmatic activity, as assessed by a decrease in Pdi swings, PTPdi, and Edi, was detected at the levels of 10 and 20 cm H2O; a further significant decrease in these values was observed when PEEPe was added. PEEPi decreased significantly only with the application of PEEPe, resulting in a small increase in end-expiratory lung volume. We conclude that NPSV improves diaphragmatic function in patients with severe stable COPD; this effect may be enhanced by the applications of external PEEP.
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Congestive heart failure (CHF) has been associated with the development of restrictive ventilatory abnormalities and decreased pulmonary diffusing capacity. Whether these physiologic changes reflect permanent alterations of lung anatomy or result solely from potentially reversible alterations of lung water is not known. To examine this issue, we reviewed the pulmonary function tests (PFTs) and cardiac catheterization data from recipients of successful heart transplants prior to and 1 year after transplantation. ⋯ Diffusing capacity for carbon monoxide was decreased before transplantation and showed a small decline after transplantation from 82.3 +/- 3.2 to 76.8 +/- 2.6 percent of predicted (p < 0.05). After correction of severe CHF by cardiac transplantation, normalization of FEV1, FVC, and TLC can be anticipated. Diffusing capacity, however, may actually decline after transplantation.
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Comparative Study
Comparison of blue dye visualization and glucose oxidase test strip methods for detecting pulmonary aspiration of enteral feedings in intubated adults.
To compare the relative utility of blue dye visualization with a glucose oxidase test strip method for detecting aspiration of enteral feedings. ⋯ Inspecting tracheal secretions for blue discoloration failed to detect most episodes of enteral feeding aspiration. Glucose oxidase test strip methods should replace blue dye visualization for detecting aspiration of enteral feedings in intubated adults.
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We report a patient who received a right single lung transplant (SLT) for progressive lymphangioleiomyomatosis and required reintubation for postoperative respiratory distress. She developed hemodynamic instability due to mediastinal shift from unilateral auto-PEEP with hyperinflation of the native lung. Placement of a double lumen endotracheal tube (DLET) and institution of differential lung ventilation restored equal lung inflation and hemodynamic stability.
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The ability of chest radiographs to determine the size of a pneumothorax was tested in 16 patients using computed tomographic (CT) scan as a reference method. To determine if CT with a slice thickness of 12 mm could be used, its accuracy was assessed in a lung model experiment. The lung model consisted of a water-filled plastic bag (lung) fitted into a plastic chamber (hemithorax), both of approximately the same size and shape as in man. ⋯ The correlation was poor (r = 0.71) irrespective of method of calculation. The size of the pneumothorax estimated by CT showed a good correlation (r = 0.99) to the initial aspirated air volumes in 12 of the 16 patients treated with drainage. A cautious attitude toward the use of chest radiographs for calculations of the degree of lung collapse in patients with pneumothorax is recommended.