American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Dec 1996
Ventilatory function in British adults after asthma or wheezing illness at ages 0-35.
The impact of past and current asthma on ventilatory function was assessed among young adults born in Britain March 3-9, 1958 who had been followed from birth to ages 7, 11, 16, 23, and 33 yr. We compared 1,060 subjects with a history of asthma, wheezy bronchitis, or wheezing with 275 control subjects with no history of chest illness. Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were measured at 34-35 yr of age before and 20 min after inhalation of 400 micrograms salbutamol, and adjusted for sex, height, and smoking by multiple regression. ⋯ Among 509 cases reporting wheeze in the past year, FEV1 and FEV1/FVC ratio were reduced to a greater extent in those with an earlier age of onset of wheeze (p < 0.001 for trend in each case). These relative reductions were greater if wheezing had persisted through childhood and adolescence, and were only partially reversed by inhalation of salbutamol. Progressive pulmonary changes related to chronic asthma may be an important mechanism underlying the association between childhood chest illnesses and chronic respiratory disease in adult life.
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Am. J. Respir. Crit. Care Med. · Dec 1996
Randomized Controlled Trial Clinical TrialCisapride improves gastric emptying in mechanically ventilated, critically ill patients. A randomized, double-blind trial.
We conducted a randomized, double-blind, placebo-controlled trial in mechanically ventilated intensive care unit (ICU) patients to evaluate the effect of cisapride on gastric emptying using an acetaminophen absorption model. We enrolled 72 patients expected to remain in the ICU for more than 48 h; 39% were female; the average age was 54.0 +/- 19.1 yr; 47% were postoperative, 83% were receiving narcotics, and the mean simplified acute physiology score (SAPS) was 9.5 +/- 3.0. Within 72 h of admission to ICU, 1.6 g of acetaminophen suspension was administered via a nasogastric tube into the stomach (Day 1). ⋯ The difference in area under the time-acetaminophen concentration curve was also greater in the patients receiving cisapride (5,534 versus 2,832, p = 0.09). We conclude that cisapride enhances gastric emptying in critically ill patients. Studies to examine the effect of cisapride on tolerance to enteral nutrition, infectious morbidity, and other clinically important outcomes are warranted.
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Am. J. Respir. Crit. Care Med. · Dec 1996
Randomized Controlled Trial Clinical TrialAntioxidant kinetics in lung lavage fluid following exposure of humans to nitrogen dioxide.
To determine if nitrogen dioxide (NO2), a gaseous free radical, modifies the protective antioxidant pool present in respiratory tract lining fluids, a random, double-blind study utilizing flexible fiberoptic bronchoscopy with bronchial and bronchoalveolar lavage was performed. Healthy, nonsmoking, asymptomatic subjects were exposed to filtered air and 2 ppm NO2 for 4 h on separate occasions. To examine the kinetics of the NO2-induced antioxidant reactions, 44 subjects were randomly assigned to one of three groups. ⋯ In marked contrast, significant increases in GSH concentration were seen at 1.5 and 6 h in bronchial lavage fluid after exposure to NO2, which subsequently returned to control levels by 24 h. No change in bronchoalveolar lavage fluid GSH concentration or malondialdehyde content was seen after NO2 exposure. These data support the view that antioxidants present in lung fluids react with, and hence modulate the impact of, NO2 on the lung.
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Am. J. Respir. Crit. Care Med. · Dec 1996
Influence of gender and endotracheal tube size on preextubation breathing pattern.
An imbalance between work of breathing and respiratory muscle capacity often results in rapid, shallow breathing (increased respiratory rate/tidal volume [f/VT]). Because this imbalance commonly causes unsuccessful weaning from mechanical ventilation, it is not surprising that an elevated f/VT accurately predicts weaning failure. However, while studying extubation outcome, we observed that women and patients with narrow endotracheal tubes are often successfully extubated with an elevated f/VT. ⋯ Although the overall incidence of extubation failure was similar (11/82 [women] versus 23/136 [men], p = NS), among patients with f/VT > or = 100, men were more likely to require reintubation (3/19 [women] versus 5/10 [men], p = 0.08). We conclude that women, especially when breathing through small endotracheal tubes, have a higher f/VT (including likelihood of f/VT > or = 100) than men, independent of extubation outcome. Consideration of factors that elevate the f/VT, unrelated to physiologic work of breathing and respiratory muscle capacity, should improve application of this index to extubation decision making.