The American review of respiratory disease
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Am. Rev. Respir. Dis. · Aug 1993
Gastric and pharyngeal flora in nosocomial pneumonia acquired during mechanical ventilation.
We studied the interrelations between gastric, pharyngeal, proximal, and distal airway bacterial flora in ventilator-associated pneumonia (VAP) on 36 patients with nosocomial pneumonia acquired during mechanical ventilation (MV) and 27 mechanically ventilated control subjects without pulmonary infection. Gastric, pharyngeal, and endotracheal (EA) sampling for quantitative cultures were performed upon all patients, as well as fiberoptic bronchoscopy with protected specimen brush (PSB) sampling. Mean bacterial and fungi colony counts were significantly increased in pharyngeal, EA, and PSB samples in patients with VAP compared with control subjects. ⋯ In summary, the present study shows that the coincidence between microorganisms isolated in PSB cultures and those from gastric and oropharynx increase in MV patients with pneumonia, indicating that both reservoirs play a key role in the pathogenesis of pneumonia. Conceivably, preventing both gastric and pharyngeal colonization may reduce the incidence of ventilator-associated pneumonia. From all the noninvasive samples studied only endotracheal aspirate cultures were useful for inferring the etiology of some VAP pneumonias.
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Am. Rev. Respir. Dis. · Aug 1993
Bicarbonate does not increase left ventricular contractility during L-lactic acidemia in pigs.
Lactic acidosis decreases left ventricular contractility, but whether bicarbonate increases left ventricular contractility during lactic acidosis in vivo is controversial. Therefore, we measured hemodynamics and left ventricular mechanics before and after bicarbonate administration during L-lactic acid infusion in 15 anesthetized pigs. The pigs were beta-blocked and atrially paced to minimize indirect effects of acidosis on contractility. ⋯ These effects were not significantly different from the effects of saline. Bicarbonate did not significantly increase Emax (4.2 +/- 0.8 to 4.9 +/- 0.8 mm Hg/ml) and was indistinguishable from saline (5.0 +/- 0.7 to 5.2 +/- 0.7 mm Hg/ml). We conclude that bicarbonate infusion does not directly increase left ventricular contractility during lactic acidemia in pigs within this pH range.