2 Clinical Trials for Various Conditions
One course of steroids given to a mother before a premature delivery helps the lungs of the premature infant and decreases breathing problems. One course of antenatal steroids is the standard of care for threatened premature deliveries. It is unclear as to how long the benefit of one course of steroids last. The most benefit to the baby's lungs seem to occur if the steroids are given at least 24 hours before but within 7 days of a premature delivery. It is difficult to predict the timing of a preterm delivery so deliveries often do not occur within this time period. We hypothesize that the benefits of the steroids to the lungs wear off if the steroids are given more than 14 days before a preterm delivery, and that in these circumstances an extra course of steroids will help the premature baby's lungs and the premature baby will have less breathing problems as shown by lung function testing.
The goal of this study is to describe the influence of the chest wall on the respiratory system mechanics in morbidly obese patients and in patients with high intra-abdominal pressure. The effects of increasing and decreasing positive end-expiratory pressure (PEEP) on chest wall and total respiratory system mechanics, lung volumes and gas exchange will be evaluated, both during controlled and assisted mechanical ventilation. Patients will be studied, first, during the acute phase of respiratory failure, when requiring intubation and controlled mechanical ventilation. Then, patients will be evaluated again during weaning from the ventilator to assess the influence of PEEP in assisted ventilation prior to extubation.