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The initial experience with continuous positive airway pressure (CPAP) may predict subsequent compliance. In a retrospective study, we found that premedication with nonbenzodiazepine sedative-hypnotic agents during CPAP titration polysomnography independently predicted short-term compliance. To validate these findings, we conducted a prospective clinical trial to assess whether premedication with eszopiclone prior to CPAP titration would improve short-term CPAP compliance.

Pharmacotherapy for restless legs syndrome (RLS) may be ineffective or complicated by side effects. Uncontrolled series using pneumatic compression devices (PCDs) have been shown to reduce symptoms of RLS. We sought to assess the efficacy of PCDs as a nonpharmacologic treatment for RLS.

Acute and chronic pulmonary and cardiac diseases often have a high mortality rate, and can be a source of significant suffering. Palliative care, as described by the Institute of Medicine, “seeks to prevent, relieve, reduce or soothe the symptoms of disease or disorder without effecting a cure. Palliative care in this broad sense is not restricted to those who are dying or those enrolled in hospice programs.” The American College of Chest Physicians strongly supports the position that such palliative and end-of-life care of the patient with an acute devastating or chronically progressive pulmonary or cardiac disease and his/her family should be an integral part of cardiopulmonary medicine. This care is best provided through an interdisciplinary effort by competent and experienced professionals under the leadership of a knowledgeable and compassionate physician. To that end, it is hoped that this statement will serve as a framework within which physicians may develop their own approach to the management of patients requiring palliative care.

Opinions regarding do-not-resuscitate (DNR) decisions differ between individual physicians. We attempted to determine whether the strength of DNR recommendations varies with medical specialty and experience.

Pulse oximetry is a well-established tool routinely used in many settings of modern medicine to determine a patient's arterial oxygen saturation and heart rate. The decreasing size of pulse oximeters over recent years has broadened their spectrum of use. For diagnosis and treatment of sleep-disordered breathing, overnight pulse oximetry helps determine the severity of disease and is used as an economical means to detect sleep apnea. In this article, we outline the clinical utility and economical benefit of overnight pulse oximetry in sleep and breathing disorders in adults and highlight the controversies regarding its limitations as presented in published studies.

There have been 15 published cases of probable pentamidine-induced torsade de pointes (TdP). A prospective analysis of this complication of therapy is valuable considering the high frequency of Pneumocystis cariniipneumonia in the AIDS population, and the role of pentamidine in its therapy.

Lymphangioleiomyomatosis is a rare disease which afflicts young women of childbearing age. It is sufficiently uncommon that randomization or any other systematic evaluation of regimens of treatment has been difficult. Review of scattered case reports implies that a number of hormonal manipulations may be equally effective. A comprehensive review of the literature revealed 30 cases of LAM treated with eight regimens of treatment. Evaluation with predetermined criteria (meta-analysis) shows that administration of progesterone or oophorectomy or both are the most effective treatments, resulting in improvement or stabilization of the disease in the majority of cases.

Eucapnic voluntary hyperventilation (EVH) of dry gas is a physiologic bronchoprovocation challenge useful in the diagnosis of asthma. To determine the best parameter and threshold for diagnosis and the proper timing of postchallenge measurements, we reviewed 120 challenges, comparing the decrement from baseline in FVC, FEV1, mean forced expiratory flow during the middle half of the FVC (FEF25–75%), and peak expiratory flow rate (PEFR) each at 0, 5, 10, and 20 min postchallenge. After adjustment to a standard minute ventilation of 30 times the baseline FEV1for 6 min, the mean response by 90 mild asthmatics differed from 30 normal subjects in all four parameters (p<0.0001). In asthmatics, maximum decline from baseline (meant±SEM) was as follows: FVC, 12.1±1.2%; FEV1, 19.7±1.7%; FEF25–75%, 33.5±2.5%; and PEFR, 29.0 ±1.9%. Normal subjects had a maximum fall as follows: FVC, 2.9±0.7%; FEV1, 3.8±0.7%; FEF25–75%, 11.8±2.0%; and PEFR, 11.5±1.0%. Based on comparison of receiver operator characteristic curves, FEV1was more accurate than FEF25–75%and equivalent to FVC and PEFR. A threshold of 10% change or greater in FEV1had a specificity of 90%, with a sensitivity of 63.3%. A threshold of 15% or greater had a specificity of 100%, with a sensitivity of 53.3%. The FEV1fell by 10% or more in 55 of 90 asthmatics at 5 or 10 min after hyperventilation. Measurements at 0 or 20 min added two additional positive responses. We conclude that in the proper clinical setting, subjects whose FEV1declines by 10% or more at 5 or 10 min after EVH should be diagnosed as having asthma.

Oxygen consumption ( V˙o2) and minute ventilation ( V˙e) were measured breath-by-breath for 10-min periods in the third trimester of pregnancy in 16 healthy women. These measurements were repeated during the first stage of labor in eight of the women. The 10-min mean V˙o2was 3.56 ml/kg/min (± 0.82 SD) at term and 4.28 ml/kg/min (± 0.93) during labor, for an average increase of 23 percent (± 28 percent, p = 0.04) from third trimester to labor. The mean V˙ewas 0.15 L/kg/min (±0.03) at term and increased significantly (p = 0.05) to 0.24 L/kg/min (±0.11) during labor for an average increase in V˙eof 65 percent (± 78 percent). Peak V˙o2and V˙eoccurred during contractions with five-breath average peak V˙o2being 86 percent (± 53%) above the 10-min mean value at term and V˙eincreasing 167 percent (± 154 percent) from third trimester to peak values during labor. These data may be useful in identifying patients at risk for developing respiratory insufficiency during labor. We propose an algorithm for approaching the obstetric patient with respiratory disease.

The thresholds used to define a positive result for bronchial provocation challenges (BPC) are arbitrary. Requiring smaller decrements in expired flow to define a positive study would capture more cases of reactive airways (increased sensitivity) but would include some “normal” responses (decreased specificity). To examine the relationship between threshold definition and the ability to correctly classify subjects as either normal or as having airways hyperresponsiveness (AHR), four different BPC tests were administered on different days to 20 patients with a clinical diagnosis of exercise-induced bronchospasm (EIB) and 20 control subjects. The four BPC tests were indoor exercise on a cycle ergometer, methacholine inhalation challenge (MIC), eucapnic voluntary hyperventilation (EVH) with dry gas, and EVH with cold gas. Our results indicate that the thresholds which best separate the two groups are different for each of the four BPC techniques. For methacholine inhalation (MIC), a fall in FEV1(d%FEV1) of 15 percent or greater at 188 cumulative breath units was 100 percent specific for AHR but had a sensitivity of only 55 percent. Eucapnic voluntary hyperventilation (EVH) with room temperature dry gas was 100 percent specific at a d%FEV1of 11 percent, but, at that threshold, sensitivity was only 50 percent. EVH with cold air was 100 percent specific at a d% FEV1of 12 percent but sensitivity was only 35 percent. The bicycle ergometer challenge was far too insensitive to be of value in evaluating AHR. Based on their respective receiver operating characteristic curves, the best separation of the two subject groups occurred at a d%FEV1of 5 percent and 12 percent for the two EVH techniques and MIC, respectively. An individual’s response to one test was highly correlated with the response to either of the other two (r = 0.66, p<0.001 for dry vs cold gas EVH; r = 0.56, p<0.001 for dry gas EVH vs methacholine; and r = 0.69, p<0.001 for cold gas EVH vs methacholine). Thus, MIC and EVH techniques are equally useful in defining AHR and each has its optimal threshold for a positive test result.