In this diagnostic test evaluation of a nasal flow monitoring device for obstructive sleep apnea (OSA), 34 patients referred for polysomnography were studied at home for three consecutive nights with the monitor. The mean age of subjects (±SD) was 41.9±10.3 years, and their mean apnea-hypopnea index (AHI) was 31.5±27.2. The difference between the average AHI from three nights at home on the monitor and the polysomnogram (PSG) result was 1.8±17.1. The area under the receiver operating characteristic curve (AUC) for PSG All ? 10 was .96. With a threshold AHI of 18 on the flow monitor, sensitivity was .92, specificity .86, positive predictive value .96, and negative predictive value .75. For detecting severe OSA (AIR ? 30), the AUC was .85. With knowledge of appropriate thresholds and the pretest risk of OSA, the flow monitor can be used to detect or exclude OSA for sleep-related research, as well as to identify severe cases needing priority for further evaluation.
Systemic opiates may relieve dyspnoea and improve exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). Small doses of inhaled opiates may have similar effects; however, recent studies have shown no benefit. We studied higher doses of inhaled morphine and measured systemic absorption to determine whether any beneficial actions are local or systemic.Twenty and 40 mg doses and 0.9% saline were nebulized in a randomized, double-blind study of 16 patients with stable COPD. Patients performed 6 min walk tests immediately after the nebulized test solution (Walk 1) and again 60 min later (Walk 2). Arterial oxygen saturation (Sa,O 2 ), modified Borg dyspnoea score and cardiac frequency were recorded during each walk.There was no difference between placebo and either dose of nebulized morphine on these measurements. The higher dose of nebulized morphine achieved a higher plasma concentration. The highest plasma concentration was measured immediately after nebulization, and this decreased steadily in the hour thereafter (p<0.002). There was no correlation between the change in walk distance and the change in plasma morphine concentration after either dose of nebulized morphine.We conclude that higher doses of nebulized morphine do not improve exercise endurance or relieve dyspnoea in patients with chronic obstructive pulmonary disease, and that morphine is rapidly absorbed systemically after inhalation.
The case records of 11 patients with cystic fibrosis (CF) who had 13 completed pregnancies between 1975 and 1995 were retrospectively reviewed to assess: (1) the changes in spirometry and body mass index (BMI) during pregnancy; and (2) maternal and neonatal complications and outcomes. Prepregnancy the mean age of the group was 24 (range 17-27) years. Two patients were exsmokers, 7 had pancreatic insufficiency and 7 had chest X-ray evidence of bronchiectasis. None of the patients had diabetes mellitus but 3 developed gestational diabetes. The mean +/- SEM (% predicted) forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) prepregnancy were 2.3 +/- 1.0 (83%) litres and 3.0 +/- 0.9 (85%) litres respectively. Five patients had normal spirometry (FEV1 and FVC >80% predicted) prior to 6 pregnancies. The mean body mass index (kg/height(m)2) for the group was 20.5 +/- 2.0. There was a significant decline in spirometry during pregnancy (FEV1 15.5 +/- 6.6% p<0.01; FVC 14.0 +/- 8.3% p<0.5). However, FVC but not FEV1 recovered to prepregnancy values by 12 months postpartum. There was a significant increase in both weight (7.1 kg) and BMI (2.6 kg/height(m)2) at the time of delivery compared with prepregnancy (p=0.0004). However, postpregnancy both weight and BMI had returned to their prepregnancy values (p<0.2). Mothers with an FEV1>80% had less decline in FEV1 related to pregnancy, better outcomes, fewer operative and instrumental deliveries, fewer preterm infants and fewer neonatal complications. Suggestions for the planning and management of pregnancy in women with CF are discussed.
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