Indicators of obstructive sleep apnea - II
A complete evaluation to diagnose sleep apnea is best done in an overnight sleep center. There, technicians can record your breathing, heart rate, brain waves and other measurements. You'll find out if the apnea is mild, moderate or severe.
CARDIOVASCULAR AND CEREBROVASCULAR DISEASE -- There is evidence that habitual snoring and obstructive sleep apnea may increase the risk of cerebrovascular accidents and ischemic heart disease independently of such confounding variables as age, cholesterol level, obesity, hypertension, pre-existing heart disease, smoking, or alcohol consumption.
RESPIRATORY FAILURE -- Patients who have obstructive sleep apnea in addition to obstructive pulmonary disease, hypercarbia, or hypoxemia are predisposed to severe respiratory failure and death. Treatment of sleep apnea effectively prevents respiratory failure.
Indications for treatment - Treatment of obstructive sleep apnea appears to be indicated for all patients with an apnea index higher than 20, because the mortality in this group is higher than that in patients with an apnea index below 20. Also, because the risk of morbidity from cerebrovascular and cardiovascular events and automobile accidents is increased in persons with the disorder, treatment is indicated for those with cardiovascular risk factors (e.g., smoking, hypercholesterolemia, hypertension, family history) or daytime sleepiness, regardless of the apnea index.
Medical options Obstructive sleep apnea can be approached medically, with or without the use of drugs.
GENERAL MEASURES -- A significant decrease in snoring and episodes of apnea occurs if the patient sleeps on his or her side. Sleeping in this position can be promoted by sewing a tennis ball into the back of the pajamas. Another simple measure is avoidance of alcohol and sedatives before bedtime.
WEIGHT LOSS -- Amelioration of sleep apnea may follow weight loss achieved through either dieting or gastric surgery. Possible improvement in or resolution of anatomic abnormalities and relief of hypoxemia are proposed as mechanisms.
CPAP -- Nasal CPAP remains first-line therapy for obstructive sleep apnea. During the first nights of treatment, nightmares and excessive dreaming may occur as a result of REM rebound. Two weeks may be needed to obtain full benefit from the therapy. Nasal CPAP prolongs survival, but it is accompanied by considerable discomfort and apprehension on the part of the patient. At The Cleveland Clinic Foundation, we have found that education, counselling, and an introduction to the equipment before initiation of therapy improve patient compliance.
Use of bi-level positive airway pressure also may improve compliance. Expiratory and inspiratory pressures can be adjusted independently so that expiratory pressures are lower than those of CPAP (the main reason for discomfort is the need for breathing out against expiratory pressure) and overall mean airway pressure is also lower. This has been proposed to reduce the potential for barotrauma, mechanical ventilatory depression, and decreased cardiac output.
OXYGEN SUPPLEMENTATION -- Nasal oxygen can be more effective than nasal CPAP in improving oxygenation and relieving hypopnea and has been proposed as an alternative form of therapy for patients with mild obstructive sleep apnea who are not hypersomnolent. Transtracheal oxygen administration has been shown to increase the oxygen saturation nadir and decrease the frequency of episodes of apnea-hypopnea, whereas nasal oxygen improves only the oxygen saturation nadir and nasal CPAP relieves only apnea-hypopnea. Transtracheal oxygen has therefore been proposed as an alternative form of therapy in patients with severe obstructive sleep apnea when CPAP is not tolerated or when oxygen supplementation is also required.