To compare the effects of noninvasive assist-control ventilation (ACV) and pressure support ventilation (PSV) by nasal mask on respiratory physiologic parameters and comfort in acute hypercapnic respiratory failure (AHRF).

STUDY OBJECTIVES AND PATIENTS: Pulmonary hypertension (PH) is common in COPD and may predict mortality in this disorder. We have compared the pulmonary vasodilator effects, dose-response characteristics, and tolerability of two calcium channel blockers, amlodipine and extended-release (ER) felodipine, in 10 patients (seven men, age 68+/-4.8 [SD] years) with clinically stable COPD and PH.

This study was designed (1) to investigate the effects of normothermic and hypothermic perfusion on the median frequency of the fibrillating myocardium, and (2) to elucidate whether frequency-guided countershock therapy improves countershock success during the reperfusion phase of cardiac surgery.

To determine the optimal treatment of empyema thoracis (within the fibrinopurulent phase of illness) comparing pleural drainage and fibrinolytic therapy vs video-assisted thoracoscopic surgery (VATS), with regard to efficacy and duration of hospitalization.

Systemic administration of beta-agonist and anticholinergic drugs markedly impair normal autonomic heart rate control. The purpose of this study was to quantify and compare the effects of therapeutic doses of inhaled albuterol and ipratropium on autonomic control of the cardiovascular system.

In comparison to beta-agonist drugs, which are the primary bronchodilator drugs in current use in asthma, both oral theophylline and inhaled ipratropium have a weaker bronchodilating action in asthma. Although a number of studies have shown an additive effect of ipratropium in combination with beta-agonist bronchodilator drugs in asthmatics, to our knowledge, the effects of combined treatment with ipratropium and theophylline have not been assessed.

Nebulizer systems used to generate therapeutic aerosols vary in their ability to deliver medication to the airway. In a recent study in 17 adults with stable asthma, albuterol given using an ultrasonic nebulizer (UN) appeared to produce greater bronchodilatation than the same dose of albuterol given by a jet nebulizer (JN). The purpose of this study was to determine if the UN used in that study would produce a better bronchodilator response in children with acute asthma than the JN system that has been in use at Cardinal Glennon Children's Hospital.

To determine the frequency of acute postoperative atelectasis in patients undergoing aortocoronary bypass with either normothermic (warm) or hypothermic (cold) technique.

To determine the efficacy of salmeterol alone in a group of patients with moderate asthma with nocturnal worsening of symptoms.

To determine the risk factors and frequency of intracranial hemorrhage among patients undergoing thrombolysis for pulmonary embolism.

gamma-Aminobutyric acid (GABA) is a central inhibitory neurotransmitter that also exists in peripheral tissues, including the lung. The GABA-agonist baclofen has been shown, in animal studies, to inhibit cough via a central mechanism, but has not been investigated in humans (to our knowledge).

To determine whether adequate concentrations of a new formulation of tobramycin could be delivered to the lower respiratory tract of patients with cystic fibrosis (CF) using a jet nebulizer delivery system.

This study determined whether proportional assist ventilation (PAV) applied during constant power submaximal exercise could enable individuals with severe but stable COPD to increase their exercise tolerance.

Atrial fibrillation (AF) is associated with impaired exercise capacity. Oxygen uptake (VO2) kinetics determines cardiopulmonary performance during submaximal exercise, which may be impaired in patients with AF.

To assess the accuracy of respiratory inductive plethysmography (RIP) waveforms to those obtained with whole body plethysmograph (BP) as this device gives a plethysmographic signal and a pneumotachograph (PNT).

Inhaled magnesium (Mg) seemed to have a mild protective (nonbronchodilator) effect against histamine and methacholine. Inhaled sodium metabisulfite (MBS) causes bronchoconstriction in asthma through indirect mechanisms that involve sensory nerve stimulation, and it is extensively used to study airway hyperresponsiveness. We designed this double-blind, randomized, crossover, and placebo-controlled study to test the effect of nebulized Mg sulfate against indirect challenge with MBS.

We have demonstrated previously that exogenous progesterone, but not estrogen, up-regulated lymphocyte beta2-adrenoceptors (beta2-AR) when given during the follicular phase in healthy women. Female asthmatics exhibit loss of the cyclical pattern of beta2-AR regulation seen in healthy women, in that there is no luteal phase rise in beta2-AR. It has been postulated that abnormal cyclical regulation of beta2-AR might be a possible mechanism for premenstrual asthma. In this study, we were interested to see how exogenous female sex-steroid hormones altered beta2-AR regulation in female asthmatics during the follicular phase, when endogenous hormone levels are normally low. Seven nonsmoking female subjects with mild asthma, with a mean (SEM) age of 26 (2) years and FEV1 of 94.7% (6.4) of predicted, completed this randomized, double-blind, crossover study. They were evaluated at two successive menstrual cycles, during the follicular phase (day 1 to 6). They were randomized to receive single oral doses of either ethinyl estradiol (ethinyloestradiol), 50 microg, or medroxyprogesterone, 10 mg. Lymphocyte beta2-AR parameters were evaluated at baseline (T0), 24 h (T24), and 72 h (T72) after ingestion. Baseline levels of progesterone and estradiol were comparable on both cycles. Receptor binding density (log Bmax; fmol/10(6) cells) decreased significantly after progesterone but not after estrogen at T24: amounting to a 1.34-fold mean difference (95% confidence interval [CI], 1.01 to 1.78) between T24 vs T0 with progesterone. Comparing Bmax for progesterone with estrogen at T24 amounted to a 1.25-fold significant difference (95% CI, 1.00 to 1.56). This was associated with a trend (p=0.06) toward a lower cyclic-adenosine monophosphate (AMP) response to isoproterenol hydrochloride (isoprenaline) 10(-4) M (Emax) at T24 vs T0 with progesterone. Receptor binding affinity (Kd) was not altered by either treatment. These results show that exogenous progesterone, but not estrogen, given during the follicular phase, decreased beta2-AR density and cyclic-AMP response in female asthmatics, in contrast to the previously observed up-regulating effect of progesterone seen in healthy women. This paradoxical effect of progesterone in female asthmatics suggests an abnormal regulation of beta2-AR and might be a possible mechanism for premenstrual asthma when progesterone levels are high during this period of the cycle.

To evaluate the safety of a combined heat and moisture exchanger filter (HMEF) for the conditioning of inspired gas in long-term mechanical ventilation (MV).