American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jul 1995
Comparative StudyEvaluation of bronchoscopic techniques for the diagnosis of nosocomial pneumonia.
To compare the usefulness of specimens obtained by bronchoalveolar lavage (BAL) and using a protected specimen brush (PSB) in the diagnosis of nosocomial pneumonia, both procedures were performed via fiberoptic bronchoscopy just after death in a series of 20 ventilated patients who had not developed pneumonia before the terminal phase of their disease and who had no recent changes in antimicrobial therapy. These results were compared with both histologic and microbiologic postmortem lung features in the same area. The total number of bacteria obtained by culture of lung segments and the latters' histologic grade were closely correlated (rho = 0.79, p < 0.0001). ⋯ Using discriminative values of > or = 10(3) and > or = 10(4) bacteria/ml to define positive PSB and BAL cultures, respectively, these techniques identified lung segments yielding > or = 10(4) bacteria/g tissue with sensitivities of 82 and 91% and specificities of 89 and 78%, respectively. Moreover, upon direct observation, the percentage of BAL cells containing intracellular bacteria was closely correlated with the total number of bacteria obtained from corresponding lung samples (p < 0.001). These findings indicate that bronchoscopic PSB and BAL samples very reliably identify both qualitatively and quantitatively microorganisms present in lung segments with bacterial pneumonia, even when the infection develops as a superinfection in a patient already receiving antimicrobial treatment for several days.
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Am. J. Respir. Crit. Care Med. · Jul 1995
Comparative StudyTitration of tidal volume and induced hypercapnia in acute respiratory distress syndrome.
Mechanical ventilation may promote overdistension-induced pulmonary lesions in patients with acute respiratory distress syndrome (ARDS). The static pressure-volume (P-V) curve of the respiratory system can be used to determine the lung volume and corresponding static airway pressure at which lung compliance begins to diminish (the upper inflection point, or UIP). This fall in compliance may indicate overdistension of lung units. ⋯ The end-inspiratory plateau pressure (Pplat) was compared to the UIP, and VT was lowered when the Pplat was above the UIP. In the range of lung volume studied on the P-V curves (up to 1600 ml), a UIP could be shown in only one control patient (at 23 cm H2O). By contrast, a UIP was present on the P-V curve obtained from all patients with ARDS, corresponding to a mean airway pressure of 26 +/- 6 cm H2O, a lung volume of 850 +/- 200 ml above functional residual capacity and 610 +/- 235 ml above PEEP.(ABSTRACT TRUNCATED AT 250 WORDS)
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Am. J. Respir. Crit. Care Med. · Jul 1995
Randomized Controlled Trial Comparative Study Clinical TrialFactors influencing cardiopulmonary effects of inhaled nitric oxide in acute respiratory failure.
The aim of this prospective study was to determine factors influencing effects of inhaled nitric oxide (NO) on the pulmonary circulation and on gas exchange in critically ill patients with acute lung injury. Twenty-one hypoxemic patients with acute respiratory failure (PaO2 = 127 +/- 69 mm Hg during intermittent positive pressure ventilation, FiO2 = 1), were mechanically ventilated with 2 ppm NO and pure oxygen. The effect of positive end-expiratory pressure (PEEP) on alveolar recruitment was assessed on an anatomic basis using a high-resolution and spiral thoracic computed tomographic (CT) scan. ⋯ In patients in whom PEEP was associated with alveolar recruitment, NO increased PaO2 by 66 +/- 24 mm Hg during ZEEP and by 104 +/- 26 mm Hg during PEEP (p < 0.01). In patients in whom PEEP did not induce alveolar recruitment, the NO-induced increase in PaO2 was similar during ZEEP and PEEP conditions (+70 +/- 15 mm Hg versus +76 +/- 12 mm Hg, NS). In patients with adult respiratory distress syndrome, factors determining NO-induced improvement in arterial oxygenation and pulmonary vascular effects are PEEP-induced alveolar recruitment and the baseline level of pulmonary vascular resistance.
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Am. J. Respir. Crit. Care Med. · Jul 1995
A dual-binding antibody to E- and L-selectin attenuates sepsis-induced lung injury.
Many studies indicate a pivotal role for neutrophil adhesion in sepsis-associated lung injury. Neutrophil adhesion to endothelium depends on activation and expression of selectin and integrin adhesion receptors. We studied the effects of pretreatment with a dual-binding porcine anti-E- and anti-L-selectin monoclonal antibody (EL-246) on a porcine model of sepsis-induced lung injury. ⋯ There was no significant difference in pulmonary and systemic hemodynamics between Groups 2 and 3. Group 4 animals exhibited a transient neutropenia, but otherwise no other differences in measured parameters were found compared with Group 1 control animals. In conclusion, EL-246 significantly reduced neutrophil accumulation in lung and attenuated sepsis-induced lung injury, but failed to attenuate deranged pulmonary and systemic hemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)