Chest
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Multicenter Study
Predicting the duration of mechanical ventilation. The importance of disease and patient characteristics.
To analyze the determinants of an individual patient's duration of mechanical ventilation and assess interhospital variations for average durations of ventilation. ⋯ For patients admitted to the ICU and ventilated on day 1, total duration of ventilation is primarily determined by admitting diagnosis and degree of physiologic derangement as measured by APS. An equation developed using multivariate regression techniques can accurately predict average duration of ventilation for groups of ICU patients, and we believe this equation will be useful for comparing ventilator practices between ICUs, controlling for patient differences in clinical trials of new therapies or weaning techniques, and as a quality improvement mechanism.
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Comparative Study
Physician-ordered respiratory care vs physician-ordered use of a respiratory therapy consult service. Results of a prospective observational study.
To assess the impact of a respiratory therapy consult service (RTCS) on practices and appropriateness of ordering respiratory care services. ⋯ These results suggest that the RTCS can be an effective strategy to allocate respiratory care strategies appropriately while conserving the costs of providing respiratory care.
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Tracheobronchial constriction in asthmatics induced by isocapnic hyperventilation with dry cold air.
Although it is well known that isocapnic hyperventilation (IHV) with dry cold air produces airway constriction in asthmatic subjects, the site of airway narrowing is nuclear. To address this issue, we have quantified the tracheal and bronchial response to IHV with dry cold air in 15 patients with mild asthma and 7 healthy control subjects. We employed the acoustic reflection technique to evaluate changes in airway cross-sectional areas caused by IHV with dry cold air. ⋯ In asthmatics, at 5 to 10 min after challenge, we found that FEV1 decreased by 22 +/- 5% (mean +/- SEM) (p < 0.0001), V30p by 33 +/- 8% (p < 0.003), intrathoracic tracheal area by 10.7% +/- 2% (p < 0.03), and main bronchial area by 14 +/- 3% (p < 0.003). At 30 min, tracheal and main bronchial areas were returned to baseline levels; however, FEV1 and V30p were still significantly decreased, by 13 +/- 3% and 16 +/- 4%, respectively. We conclude that in asthmatics, IHV with dry cold air causes both tracheal and bronchial constriction, and that recovery seems to occur first in the central airways.