Patients with OHS often have an abnormal electrocardiogram (ECG), echocardiogram, and/or cardiac catheterization.

Polysomnography (sleep study)-

Should be performed in all patients with OHS for several reasons. First, in-laboratory polysomnography is the gold-standard test for OSA, which frequently coexists with OHS and should be both identified and treated. Second, positive airway pressure therapy (CPAP), the preferred treatment for OHS, can be adjusted during polysomnography. Finally, polysomnography can give the clinician an impression of disease severity. To distinguish various subtypes, polysomnography is required.

This test requires a brief admission to a hospital with a specialized sleep medicine department where a number of different measurements are conducted while the subject is asleep; this includes electroencephalography (electronic registration of electrical activity in the brain), electrocardiography (same for electrical activity in the heart), pulse oximetry (measurement of oxygen levels) and often other modalities.

NATURAL HISTORY:

Patients with OSA are at increased risk of adverse clinical outcomes.

•           Patients with untreated severe OSA appear to have a three- to six-fold increased risk of all-cause mortality compared to individuals without OSA [2,10,13].

•           OSA is associated with hypertension, pulmonary hypertension, coronary artery disease, cerebrovascular disease, cardiac arrhythmias, and stroke [14-16]. Untreated OSA may also be associated with the development of heart failure.

•           OSA induces excessive daytime sleepiness, inattention, and fatigue, which impairs daily function, induces or exacerbates cognitive deficits, and increases the likelihood of errors and accidents [3,17].

•           Motor vehicle crashes are more common among patients with OSA than without OSA, and may have a greater impact on morbidity and mortality than the cardiovascular complications of OSA [17]. Treatment with CPAP reduces self-reported crashes by 50 to 75 percent [17].

•           Patients with OSA have a propensity for night-time cardiac death, which differs from patients without OSA [14].

•           Patients with OSA are also at greater risk for perioperative complications due to intubation difficulty or impaired arousal from sedatives [18].

•           OSA is associated with diabetes or insulin resistance, although this may be due, in part, to risk factors common to both conditions [9].

•           Patients with OSA use more medical resources, and have greater medical disability than individuals without OSA [9,10,13,14,19,20].

TREATMENT:

Choosing a therapy — The types of behavior modification that should be instituted depend upon the characteristics of the patient. Overweight or obese patients should be encouraged to lose weight. Patients with positional OSA should change their sleep position. All patients should abstain from alcohol and avoid medications that may worsen their OSA.

The choice of an OSA-specific therapy (positive airway pressure=CPAP, an oral appliance, upper airway surgery) depends upon the severity of the OSA, patient preference, and upper airway anatomy:

•           For patients with severe OSA, we use positive airway pressure as first-line therapy (CPAP).

•           For patients with mild or moderate OSA who do not express a preference, we prefer positive airway pressure rather than an oral appliance because the former is superior at reducing the frequency of obstructive events. However, we will initiate an oral appliance rather than positive airway pressure if the patient prefers an oral appliance.

•           We consider surgical therapy when positive airway pressure or an oral appliance is declined, ineffective (after at least a three month trial of therapy), or not an option.