American journal of respiratory and critical care medicine
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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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To test the respiratory effects of benzodiazepines in an established animal model of central apnea, we administered nonhypnotic and hypnotic doses of diazepam to nine adult male Sprague-Dawley rats chronically instrumented for sleep staging. In random order on separate days, rats were recorded following intraperitoneal injection of: (1) saline; (2) 0.05 mg/kg diazepam; or (3) 5 mg/kg diazepam. Normalized inspiratory minute ventilation increased significantly during wakefulness and non-rapid eye movement (non-REM) sleep following each dose of diazepam (p < 0.003 in each case) and following the highest dose during rapid eye movement (REM) sleep (p = 0.01). ⋯ The durations of non-REM and REM sleep were unaffected by the low dose, but following 5 mg/kg of diazepam non-REM sleep was increased (p = 0.03) and REM sleep was decreased (p = 0.009). We conclude that both hypnotic and non-hypnotic doses of benzodiazepines may be associated with suppression of sleep-related central apnea. We further conclude that non-REM and REM-related apneas arise from at least partially distinct mechanisms.
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Am. J. Respir. Crit. Care Med. · Mar 1998
Elevated circulating E-selectin, intercellular adhesion molecule 1, and von Willebrand factor in patients with severe infection.
To investigate interactions between the endothelium and leukocytes in patients with sepsis, we measured soluble adhesion molecules (sE-selectin and sICAM-1), von Willebrand factor antigen (vWf:Ag), myeloperoxidase (MPO), and lactoferrin (Lacto-f) as plasma markers of endothelial and neutrophil activation. We tested whether the five proteins were predictors of clinical severity, which was evaluated by simplified acute physiological score (SAPS), number of organ failures (MOF), acute lung injury (ALI), and subsequent final outcome. Levels of the five plasma markers were higher in patients with severe infection (n = 25) than in patients without sepsis (n = 7) and healthy volunteers (n = 9). ⋯ The initial sICAM-1 level appeared to be an independent prognostic variable, based on a logistic regression analysis. Unlike sE-selectin, sICAM-1 remained at high levels indefinitely in nonsurvivors. We conclude that, unlike neutrophil activation markers, levels of endothelium-derived soluble adhesion molecules and vWf:Ag in severe sepsis syndrome are correlated with the severity of illness and may be considered as predictors of survival outcome.
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Am. J. Respir. Crit. Care Med. · Mar 1998
Hypercapnia enhances the development of coughing during continuous infusion of water into the pharynx.
We investigated the effects of increasing CO2 ventilatory drive on the coordination of respiration and reflex swallowing elicited by continuous infusion of distilled water into the pharynx (2.5 ml/min) in 11 normal subjects. Ventilation was monitored using a pneumotachograph and swallowing was recorded by submental electromyogram. The CO2 ventilatory drive was increased by addition of external dead space, while ventilation, the frequency of swallows, and the timing of swallows in relation to the phases of the respiratory cycle were measured at steady-state conditions. ⋯ Signs of aspiration were never observed during continuous infusion of water at eucapnia, but seven of 11 subjects showed laryngeal irritation and/or pending aspiration during hypercapnia, and the incidence of laryngeal irritation was higher the greater the PCO2. Detailed analysis of laryngeal irritations consisting of single coughs in seven subjects revealed that the majority of laryngeal irritations occurred when swallows coincided with expiratory-inspiratory transition or when swallows coincided with inspiration, whereas laryngeal irritation after an expiratory swallow was never observed. These results suggest that the automatic respiratory control system is not influenced by continuous swallowing but that the coordination of swallowing and respiration may be compromised during hypercapnia.
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Am. J. Respir. Crit. Care Med. · Mar 1998
Randomized Controlled Trial Clinical TrialInhaled flunisolide for acute severe asthma.
This randomized, double-blind trial was designed to determine the benefit of high and cumulative doses of flunisolide added to salbutamol in patients with acute asthma in the emergency room (ER). Ninety-four patients who presented to an ER for treatment of an acute exacerbation of asthma were assigned in a randomized, double-blind fashion to receive salbutamol and placebo (n = 47) or salbutamol combined with flunisolide (n = 47). Both drugs were administered successively through a metered-dose inhaler and spacer at 10-min intervals for 3 h (400 microg of salbutamol and 1 mg of flunisolide every 10 min). ⋯ Results in the flunisolide group were significantly different from those in the placebo group at 90, 120, 150, and 180 min. Data analyzed separately in accord with the duration of the attack before presenting at the ER (< 24 or > or = 24 h) showed that the placebo > or = 24 h group produced a significantly lower FEV1 at 120, 150, and 180 min (p = 0.041) than did the remaining groups. Our data support the theory that high and cumulative doses of inhaled flunisolide administered by metered-dose inhaler with spacer and added to salbutamol are an effective therapy for patients with acute asthma and a prolonged duration of symptoms before ER presentation.