Chest
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Randomized Controlled Trial Comparative Study Clinical Trial
High-frequency jet ventilation. A prospective randomized evaluation.
Three hundred nine patients were randomly allocated to two ventilatory protocols; 157 patients were supported with a volume-cycled ventilator (VCV) (Bear Medical BEAR 1) and 152 with a high-frequency jet ventilatory (HFJV) developed at our institution. The two ventilators were compared for safety, reliability, ease of use, and efficacy in maintaining gas exchange. On VCV, end points of therapy were: fractional concentration of oxygen in the inspired gas (FIo2) less than or equal to 0.40; arterial oxygen pressure (PaO2) greater than or equal to 70 mm Hg; cardiac index (CI) greater than or equal to 3.5 L/min/sq m; and spontaneous respiratory rate less than or equal to eight breaths per minute. ⋯ Differences were statistically but not clinically significant. On HFJV, oxygenation and ventilation were maintained with lower peak inspiratory pressures and smaller tidal volumes than those required for VCV. This investigation proves that HFJV is a safe and reliable method to provide mechanical support which does not, at this time, offer obvious benefits over VCV.
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Comparative Study
A comparison of the respiratory health of Mexican-American and non-Mexican-American white children.
This study compares the respiratory health of Mexican-American and non-Mexican-American white school children. Using responses to questionnaires, the point prevalences of physician-confirmed asthma, attacks of shortness of breath with wheeze (without a diagnosis of asthma), and cough were compiled for each ethnic group. Using the results of yearly pulmonary function testing, initial and serial pulmonary function were also calculated. ⋯ Initial and serial testing of pulmonary function showed non-Mexican-American children had significantly lower maximum expiratory flows (Vmax50%) in each year of testing. These results confirm other reports of differences in both rates of asthma and pulmonary function in Mexican-Americans and non-Mexican-Americans. Inherent differences in the size of the airways could explain these findings.