Wednesday, October 29, 2014

Snoring, heart disease and sudden death

Notes from Dr. Norman Blumenstock

Despite CPAP good efficacy, it fails approximately 50% of the time due to lack of compliance.

Philippine Daily Inquirer 4:08 AM | Saturday, October 25th, 2014

So now we know better. Snoring, as a symptom of obstructive sleep apnea (OSA), is definitely not a benign disorder which carries no serious implications. It is linked with the development of difficult-to-treat high blood pressure, heart enlargement, heart failure, diabetes, accidents due to daytime sleepiness, memory lapses, irregular heartbeat and even sudden cardiac death (SCD).

Mayo Clinic researchers in the United States studied the sleep characteristics of close to 11,000 adults in an overnight sleep laboratory, and found that OSA can cause low nighttime oxygen saturation in the blood, and this may be a triggering risk factor for SCD, due to a fatal irregularity of the heart beat called ventricular fibrillation.

Some of these unfortunate patients may die suddenly in their sleep. Many cases of what we attribute to bangungot may actually be related to OSA.

In the Mayo Clinic study, OSA was one of two  factors that contributed to the highest risk of SCD. OSA has been implicated in SCD, and the study is the first large study to rigorously test the hypothesis and offer some hard evidence to support it.



Frequently overlooked
Physicians should always watch out for OSA in their heart patients and treat it promptly when present. This is a frequently overlooked problem in clinical practice.

Various treatment options are used in patients with OSA. Lifestyle measures like weight reduction in overweight individuals,  and avoiding alcohol and smoking can help and might be sufficient to treat mild cases of OSA. Medications that relax the central nervous system like sedatives and muscle relaxants should also be avoided.

A change in sleeping position can also do the trick. Many people may snore less when sleeping at a 30-degree elevation or higher of the upper body, as if sleeping on a recliner. This prevents the collapse of the airway, in the usual supine sleeping position. Sleeping on one’s side instead of sleeping on the back may also help.

For moderate to severe cases of OSA, a CPAP (continuous positive airway pressure) device can be a life-changer. An OSA patient puts on a well-fitted nasal or facial mask which is connected to the CPAP device and this helps keep the airway open when asleep.

The CPAP device is the most commonly used device for OSA, but other, newer modalities may also be used. These include the VPAP (variable positive airway pressure), also known as bilevel or BiPAP device. It monitors the patient’s breathing, and provides two different pressures, a higher one during inhalation and a lower pressure during exhalation. The VPAP or BiPAP is more expensive, and is sometimes used in patients who have other coexisting respiratory problems.

One can also read about appliances, splints or mouth guards that are being advertised in the Internet and in various health publications. All of them are designed to hold the lower jaw slightly down and forward relative to the natural, relaxed position. This position holds the tongue farther away from the back of the airway, and may be enough to help relieve apnea and improve one’s breathing during sleep. However, none of them has been shown to be more effective than the CPAP or BiPAP devices.

Premarket approval
A few months back, the United States Food and Drug Administration granted premarket approval for an upper airway stimulation system that senses respiration, and delivers mild electrical stimulation to the hypoglossal nerve in order to increase muscle tone at the back of the tongue so it will not collapse and obstruct the airway. It is powered by an implantable pulse generator, similar to a heart pacemaker device implanted in patients with heart blocks and very slow heart rates. Although the device is promising and has been shown to be effective, I think it’s a lot simpler, more convenient and economical to just use a CPAP device.

In more severe cases wherein an anatomical problem in the airway is identified, surgery may be considered to modify airway anatomy. This is still controversial and should only be considered as a final resort.

Other surgical procedures to relieve airway obstruction like straightening of the nasal septum, tonsillectomy and/or adenoidectomy, removal or reduction of parts of the soft palate, and tracheostomy (incising a hole in the anterior part of the neck to the windpipe)  may have to be done in more extreme cases.

Obstructive sleep apnea is more common than previously thought. It can become serious if undetected and untreated. It can be a stealthy killer; it comes figuratively and literally like a thief in the night. Make sure you’re not one of its victims.