The Greek word apnea literally translates to “without breath.” More than 18 million American adults experience several moments “without breath” every night, according to the National Sleep Foundation. These pauses in breathing can last from a few seconds to minutes and can occur up to 30 times per hour or more. There are three types of apnea: obstructive, central, and mixed. Of the three, obstructive sleep apnea (OSA) is the most common. If left untreated, sleep apnea can have serious or life-threatening consequences, such as high blood pressure, heart disease, and day-time sleepiness that can lead to car accidents, depression, and headaches.
Dr. Neil Skolnik and Dr. Anapriya Grover
The significance of this condition has led the American College of Physicians (ACP) to publish guidelines regarding the management of OSA in adults. These guidelines are intended to provide clinicians with evidence-based recommendations that will have positive, long-term effects on patients’ cardiovascular risk, as well overall health and quality of life.
Recommendation 1: Encourage weight loss in all overweight and obese patients diagnosed with OSA.
There is strong evidence that shows how weight loss interventions can reduce the apnea/hypopnea index (AHI) and improve symptoms. The apnea/hypopnea index is a measure of the number of apnea and hypopnea episodes per hour of monitored sleep. According to the American Academy of Sleep Medicine, an OSA diagnosis is defined by ≥ 15 events/hr (with or without OSA symptoms) or ≥ 5 events/hr with OSA symptoms. Severity of OSA is classified as:
• Mild: 5-14 events/hr
• Moderate: 15-30 events/hr
• Severe: >30 events/hr
In patients with mild OSA, weight loss alone can be sufficient to normalize the apnea/hypopnea index, thereby reducing the need for continuous positive airway pressure (CPAP). In those with persistent OSA, weight loss can reduce the amount of PAP pressure required, which can increase tolerance of and adherence to CPAP. However, weight loss alone may not be sufficient to reduce OSA in all patients. In obese patients, weight loss must be encouraged with another primary treatment. In a meta-analysis of 342 patients in 12 published trials, weight loss produced substantial reductions in apnea/hypopnea index; however, the majority of patients continued to have persistent OSA after significant weight reduction. So, while weight loss should always be encouraged in patients with OSA, it should not be assumed that this intervention alone will be sufficient; patients need to be reassessed to determine whether OSA persists and if so, CPAP should be continued.
Recommendation 2: Prescribe CPAP as the initial therapy for patients diagnosed with OSA.
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Sleep apnea sufferer being treated by CPAP via mask and air tube from machine.
CPAP is as critical as it is effective not only in reducing the AHI but also in improving sleep continuity and architecture and decreasing the sleep hypoxia that is associated with OSA. Because of the lack of adherence to CPAP, many new features have been added including heated humidification, broad pressure adjustments, and expiratory pressure relief; while many of these features mildly improve patients’ preferences, there is no evidence to suggest that these changes improve efficacy or adherence. Again, it is critical that each patient’s needs be taken into consideration. Some patients, particularly those with mild forms of OSA, may not need CPAP and instead, may benefit from positional therapy or weight loss. Other therapy such as surgery or mandibular advancement devices (MADs) may be better suited for some patients despite their lessor effectiveness when compared with CPAP.
Recommendation 3: Consider MAD as an alternate therapy to CPAP for patients diagnosed with OSA who prefer MAD or for those with adverse effects associated with CPAP.
MADs have been recommended for patients with moderate to severe OSA, those with apnea/hypopnea index values between 18-40 events/hour, and for individuals who experienced adverse events on CPAP or who can’t tolerate using it. While CPAP still is considered to be primary therapy, for those who must use a mandibular advancement device, it can often be very effective. Patients may find it easier to be compliant with MAD than with CPAP. One group of researchers observed that MADs were able to provide appropriate decrease in obstructive events in 70% of patients with mild OSA, 48% of those with moderate OSA, and 42% of those with severe OSA (Chest 2011:139:1331-9). The ACP concluded that, without sufficient evidence, it is unclear which patients will benefit from MADs. Data from several studies show that patients who are younger and thinner, with less severe OSA, may benefit more from the use of MADs. Although the ACP does not recommend surgery or pharmaceutical therapy for OSA, the ACP does acknowledge that it may work for certain patients. However, the documented efficacy rate ranges from 20%-100%, thereby making it challenging to determine its true effect.