Comparison of three auto-adjusting positive pressure devices in patients with sleep apnoea

Auto-adjustable continuous positive airway pressure (APAP) devices are an emerging treatment alternative to fixed-pressure continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea syndrome. They have been engineered to automatically adjust the pressure to the optimal level on a continuous basis. However, not all APAP technologies use the same algorithm. Three different APAP devices (Autoset Spirit, Breas PV 10i and RemStar Auto) were compared in a randomised crossover trial in patients already established on fixed-pressure CPAP therapy. The outcome measures were compliance, quality of life and side-effects. Twenty-seven middle-aged patients (25 male) previously diagnosed with severe obstructive sleep apnoea syndrome (median (interquartile range) apnoea/hypopnoea index 48 (29-76)), established on CPAP therapy for >3 yrs, were randomised to each APAP device for 4 weeks. Mean pressure and patient compliance were significantly lower on the Breas PV 10i than on the other APAP devices. The devices were similar in terms of quality of life, daytime sleepiness and upper airway side-effects, but patients evaluated them significantly differently in terms of device features, sleep quality and pressure comfort, with the Breas PV 10i being the least popular. Auto-adjustable positive airway pressure devices differ in pressure delivery and patient compliance in obstructive sleep apnoea syndrome patients.

Comparison of the effects of inhaled SCH 1000 and fenoterol on exercise-induced bronchospasm in children

The effect of 40 microgram of SCH 1000 (ipratropium bromide, an anticholinergic agent) on bronchodilation and suppression of exercise-induced bronchospasm (EIB) was compared with 400 microgram of fenoterol and a placebo in a single-blind controlled study. Twenty-seven randomly selected asthmatic children performed a standardized treadmill exercise challenge and the 17 children who were shown to have EIB continued in the study. Pulmonary function was evaluated before and after drug administration and exercise. When individual results were analyzed and grouped according to the responsiveness of EIB to the drugs, two patterns emerged: (1) the EIB was more severe in those (6/17) children who did not respond to either drug than in the rest of children; (2) the resting pulmonary function was significantly better in the children (4/17) who responded to both drugs than in those (7/17) who responded to fenoterol alone. In conclusion SCH 1000 was shown to be an effective bronchodilator comparable to, but no better than, fenoterol. It had minimal side effects. As an EIB inhibitor it depended on relatively normal base line pulmonary function and only a moderate deterioration following exercise, whereas fenoterol depended on the exercise response alone. Although anticholinergic drugs are not very extensively used, SCH 1000 may be useful in some patients where the beta 2 adrenergic drugs cause signficant side effects or are contraindicated.