American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Apr 1998
Nosocomial pneumonia in patients with acute respiratory distress syndrome.
To describe the epidemiologic and microbial aspects of ventilator-associated pneumonia (VAP) in patients with acute respiratory distress syndrome (ARDS), we prospectively evaluated 243 consecutive patients who required mechanical ventilation (MV) for > or = 48 h, 56 of whom developed ARDS as defined by a Murray lung injury score > 2.5. We did this with bronchoscopic techniques when VAP was clinically suspected, before any modification of existing antimicrobial therapy. For all patients, the diagnosis of pneumonia was established on the basis of culture results of protected-specimen brush (PSB) (> or = 10(3) cfu/ml) and bronchoalvelolar lavage fluid (BALF) (> or = 10(4) cfu/ml) specimens, and direct examination of cells recovered by bronchoalveolar lavage (BAL) (< or = 5% of infected cells). ⋯ The organisms most frequently isolated from patients with ARDS and VAP were methicillin-resistant Staphylococcus aureus (23%), nonfermenting gram-negative bacilli (21%), and Enterobacteriaceae (21%). These findings confirm that microbiologically provable VAP occurs far more often in patients with ARDS than in other ventilated patients. Because these patients are often treated with antibiotics early in the course of the syndrome, the onset of VAP is frequently delayed after the first week of MV, and is then caused mainly by methicillin-resistant S. aureus and other multiresistant microorganisms.
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Am. J. Respir. Crit. Care Med. · Apr 1998
Risk factors and outcome of nosocomial infections: results of a matched case-control study of ICU patients.
Intensive-care-unit (ICU) patients are at risk for both acquiring nosocomial infection and dying, and require a high level of therapy whether infection occurs or not. The objective of the present study was to precisely define the interrelationships between underlying disease, severity of illness, therapeutic activity, and nosocomial infections in ICU patients, and their respective influences on these patients' outcome. In a 10-bed medical ICU, we conducted a case-control study with matching for initial severity of illness, with daily monitoring of severity of illness and therapeutic activity scores, and with analysis of the contribution of nosocomial infections to patients' outcomes. ⋯ Such consequences were observed in patients who developed multiple infections. These findings suggest that a persistent high level of therapeutic activity and persistent impaired consciousness are risk factors for nosocomial infections in ICU patients. These infections are responsible for excess mortality, prolongation of stay, and excess therapeutic activity resulting in important cost overruns for health-care systems.
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Am. J. Respir. Crit. Care Med. · Apr 1998
Effect of dexfenfluramine treatment in rats exposed to acute and chronic hypoxia.
The anorexiant dexfenfluramine, which inhibits 5-hydroxytryptamine (5-HT) uptake, has been associated with an increase in the relative risk of developing primary pulmonary hypertension. The aim of this study was to investigate in rats whether dexfenfluramine (1) alters the pulmonary vasomotor effects of 5-HT and (2) aggravates the development of pulmonary hypertension during exposure to various levels of chronic hypoxia. In isolated lungs from normoxic rats, dexfenfluramine up to 10(-4) M did not elicit any vasoactive effects, and neither did pretreatment with dexfenfluramine (10[-5] M in the perfusate) modify the vasoactive effects of 5-HT. ⋯ In contrast, a continuous 5-HT infusion providing a sustained increase in plasma 5-HT levels was associated with increased muscularization of distal pulmonary arteries in response to 10% O2. Simultaneous administration of dexfenfluramine prevented the effect of exogenous 5-HT on vascular remodeling. Our findings show that dexfenfluramine does not potentiate the development of pulmonary hypertension in rats exposed to chronic hypoxia, despite its effect on plasma 5-HT concentrations.
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Am. J. Respir. Crit. Care Med. · Apr 1998
Biography Historical ArticleBlood gas analysis and critical care medicine.