Sleep medicine
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Sleep disorders are common among all age groups, but repeated studies have demonstrated that physicians underdiagnose sleep disorders. Lack of curriculum time and the limited number of faculty with expertise in sleep medicine have been cited as major barriers for sleep medicine instruction. This paper describes the development, implementation, and evaluation of an integrated selective in sleep medicine for fourth-year medical students. ⋯ A well-designed fourth-year integrated selective improves student knowledge in sleep medicine and may provide an opening for additional inclusion of sleep medicine instruction for various trainees.
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Obstructive sleep apnea (OSA) is characterized by repetitive nighttime obstructions of the upper airway that induce hypoxemia, hypercapnia, sympathetic activation, and arousals. This disorder induces cardiovascular autonomic imbalance and contributes to the development of hypertension. While the diagnostic and prognostic utility of exercise testing is well established in cardiology, the clinical utility of the exercise test in screening for OSA has not been carefully explored. To explore this potential application, we contrasted cardiopulmonary responses to exercise testing in patients recently diagnosed with OSA with apparently healthy counterparts of similar physical inactivity history, age, and body habitus. ⋯ Patients with OSA have a distinctive response to graded exercise, characterized by a blunted HR response, markedly delayed systolic BP response in early recovery, and elevated diastolic BP in both exercise and early recovery. Clinical trials are justified to determine the clinical utility of graded exercise testing to independently inform clinical decision-making for triaging patients to diagnostic polysomnography.
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Randomized Controlled Trial
Effect of atrial overdrive pacing on obstructive sleep apnea in patients with systolic heart failure.
Obstructive sleep apnea (OSA) is associated with cardiovascular disease. Preliminary studies suggested breathing improvement in patients with apnea and heart disease when atrial overdrive pacing was applied during sleep. However, more recent studies do not show significant beneficial effect for atrial overdrive pacing in OSA. To further investigate this relationship, we conducted a randomized clinical trial evaluating the effect of atrial overdrive pacing on sleep-related breathing events in subjects with OSA and systolic heart failure. ⋯ While statistically reliable, the small pacing-related reduction in sleep-disordered breathing (SDB) events is of unknown clinical significance. By contrast, continuous positive airway pressure (CPAP) dramatically improved AHI, AI, respiratory arousal index, and O(2) saturation. Thus our data suggest that overdrive pacing exerts a mild effect on respiratory events in some heart failure patients with OSA; however, atrial overdrive pacing was not therapeutically effective for improving airway patency and sleep-related respiratory function.
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Children diagnosed with attention-deficit/hyperactivity disorder (ADHD), based on Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV) criteria, may also have obstructive sleep apnea (OSA), but it is unclear whether treating OSA has similar results as methylphenidate (MPH), a commonly used treatment for ADHD. ⋯ A low AHI score of >1 considered abnormal is detrimental to children with ADHD. Recognition and surgical treatment of underlying mild sleep-disordered breathing (SDB) in children with ADHD may prevent unnecessary long-term MPH usage and the potential side effects associated with drug intake.
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Narcolepsy is a sleep disorder with clinical symptoms attributed to a reduced activation of the arousal system. Cyclic alternating pattern (CAP) is the expression of rhythmic arousability during non-rapid eye movement (NREM) sleep. CAP parameters, arousals and conventional sleep measures were studied in narcoleptic patients with cataplexy. ⋯ The reduced periods of CAP in narcoleptic NREM sleep could be the electroencephalographic (EEG) expression of a generally reduced arousability or an increased strength of sleep-promoting forces in the balance between sleep and arousal systems. This can explain some of the clinical correlates of the disorder, i.e. excessive sleepiness, short sleep latency and impaired attentive performances, even without any sign of arousal-induced sleep fragmentation.