American journal of respiratory and critical care medicine
-
Am. J. Respir. Crit. Care Med. · Oct 1995
Comparative StudyAlbuterol delivery in a model of mechanical ventilation. Comparison of metered-dose inhaler and nebulizer efficiency.
Using an in vitro model, we compared efficiencies of jet nebulizers and metered-dose inhalers (MDI) with actuator devices to deliver albuterol in various conditions of mechanical ventilation. Factors tested included influence of humidification, MDI actuator device (Aerovent spacer or Marquest 172275 MDI adaptor), and synchronization of MDI to the respiratory cycle. With the nebulizer (AeroTech II) filled with 2.5 mg albuterol sulfate in 3 ml water and run until dry, inhaled mass was 42 +/- 2.6% and mass median aerodynamic diameter (MMAD) was 1.3 microns on a nonhumidified circuit. ⋯ All other MDI actuations led to essentially biphasic distributions, with particles greater than 1 micron following a distribution similar to the nebulizer and the overall MMAD estimated to be 0.22 microns. The AeroTech II delivered a cumulative 1,000 micrograms of drug (2,500 x 0.40) over 40 min. To achieve that amount, the MDI connected to the Aerovent and used in its most efficient sequence would require 45 timed puffs (90 micrograms per puff, 25.1% mean inhaled mass) and take 45 min of an experienced therapist's time.(ABSTRACT TRUNCATED AT 250 WORDS)
-
Am. J. Respir. Crit. Care Med. · Oct 1995
Randomized Controlled Trial Comparative Study Clinical TrialSupplemental oxygen during sleep in children with sleep-disordered breathing.
Supplemental O2 is sometimes used to treat children with the obstructive sleep apnea syndrome (OSAS). However, its effects have not been studied. We therefore evaluated the use of supplemental O2 during sleep in children with OSAS. ⋯ We conclude that breathing supplemental O2 during sleep in children with OSAS results in improved oxygenation and in most cases does not exacerbate sleep-disordered breathing. However, end-tidal PCO2 should be monitored in children with OSAS receiving O2 therapy. We speculate that supplemental O2 does not depress the ventilatory drive during sleep in most children with OSAS.
-
Am. J. Respir. Crit. Care Med. · Oct 1995
Comparative StudyClinical risk factors for pulmonary barotrauma: a multivariate analysis.
Previous investigations have suggested that elevated airway pressures increase the risk of ventilator-induced pneumothorax. However, risk factor analysis using multivariate techniques has not been done. We investigated the hypothesis that airway pressures would not independently correlate with pneumothorax when underlying disease was considered. ⋯ A similar analysis performed on the ARDS population revealed independent correlation only with male sex. Trends toward elevation in airway pressures were seen that did not reach statistical significance. We conclude that development of pneumothorax is most closely correlated with underlying disease, specifically ARDS, and that the associations previously noted between airway pressures and barotrauma largely relate to the occurrence of high airway pressures in ARDS.
-
Am. J. Respir. Crit. Care Med. · Sep 1995
Incidence of the adult respiratory distress syndrome in the state of Utah.
To determine the incidence of the adult respiratory distress syndrome (ARDS) in Utah, we prospectively screened intensive-care-unit (ICU) patients for ARDS in six of the 40 general acute-care hospitals in Utah. Over a 1-yr period, we diagnosed severe ARDS (oxygenation criterion: PaO2/PAO2 < or = 0.2) in 110 patients. Of these patients, 27 were not residents of Utah. ⋯ Incorporating these two estimates, we calculated an estimated upper limit for ARDS incidence in Utah of 8.3 ARDS patients per 100,000 total Utah population per year. Using only directly identified Utah residents with ARDS, we calculated the absolute lower limit for ARDS incidence in Utah to be 4.8 ARDS patients per 100,000 Utah population per year. The incidence of ARDS in Utah is about an order of magnitude less than the 1972 National Heart and Lung Institute Task Force estimate of ARDS incidence in the United States, but agrees with more recently published ARDS incidence figures.