Friday, January 28, 2011

Sleep Apnea Increases Pulmonary Complications After Surgery

There is an article in the January issue of Anesthesia & Analgesia that warns that patients with sleep apnea have more frequent pulmonary complications after orthopedic and general surgery. I am not sure if this included sleep apnea patients that were treated. The risk of being intubated and put on a mechanical ventilator went up five-fold after orthopedic surgery and two-fold after general surgery. Other complications that were increased after these surgeries included aspiration pneumonia (lung infection after stomach contents are inhaled) and pulmonary embolus (lung clots).

This study points to the importance of pre-surgical screening for sleep apnea, so that anesthesiologists and surgeons are aware of the risk. Also, it would be interesting to know if treating sleep apnea reduces these pulmonary risks.

Monday, January 24, 2011

The Sleepover


There was an article recently about sleepovers. The author talked to psychologists about the topic. They say the appropriate age is 7 to 9 years to start. If you have a child younger than seven, they might not be ready emotionally for the sleepover. Also, you should make sure your child is emotionally ready, even if they are seven or older. Some kids just aren't ready to sleep in a different place and/or away from mom or dad. If you feel your kid is too young or just not ready, the psychologists suggest an extend visit where the kids have dinner, watch a movie, and then are home by 10 PM.

They say that two kids is best for a sleepover, as more than that can be difficult to control and gets more complicated. Have your child bring their favorite pillow, a stuffed animal, a sleeping bag, their cell phone, and even a flash light. Also, sleeping in the bedroom or the family room is appropriate. However, the psychologists warn about having kids sleep together in a bedroom if it is a co-ed sleepover, especially if the kids are a little older.

If you have dietary preferences for your child, you need to discuss this before with the parents of the kid who is having the sleepover. Also, remind your child of the rules regarding what they can eat. As a parent, you should also attempt to find out what the activity plan is before - a movie, video games, etc. If you don't want your child to watch the movie or play the video games, politely decline the offer for the sleepover.

Friday, January 21, 2011

CPAP, Fatigue, and Sleepiness

An article getting some press is in the January edition of the Sleep Journal. In it, the authors discuss how people use the terms sleepiness and fatigue as if they were the same thing - but they are not. In patients with obstructive sleep apnea (OSA), patients sometimes complain more of fatigue, tiredness, and lack of energy rather than sleepiness. CPAP has been shown to reduce subjective (patient-perceived) and objective (measurable) sleepiness, but has not been shown conclusively to reduce fatigue.

The authors investigated the levels of fatigue, energy/vigor, and sleepiness before and after a three week trial of CPAP in OSA patients. They compared using therapeutic CPAP to fake (sham) CPAP. A total of 59 patients were studied.

The results showed that therapeutic CPAP significantly reduced fatigue and sleepiness, and increased energy/vigor levels compared to sham CPAP. Of note, CPAP was only able to reduce sleepiness in those patients who had a high degree of sleepiness before CPAP. This makes sense and is consistent with what I see in my practice. The authors theorize that fatigue might improve with CPAP because it reduces inflammation that can be seen in untreated OSA.

One reason this study is important is because of the effects on fatigue and energy/vigor levels. This is a common complaint in patients with OSA and is not measured regularly by us sleep physicians. Perhaps it is time we did include a fatigue measure the same way we always ask about sleepiness.

Sunday, January 16, 2011

CPAP Use, Sleepiness, Quality of Life, and Daytime Functioning

In the January issue of Sleep, there is an article that studied the effect of three months of CPAP use on daytime sleepiness, daytime mental functioning, and quality of life in patients diagnosed with moderate to severe obstructive sleep apnea (OSA).

The authors explain that excessive daytime sleepiness (EDS) is common in patients with and without OSA. Other causes of EDS are obesity, age, typical sleep duration, diabetes, and smoking. Also, studies have shown that EDS does not improve in every patient with OSA even if they are optimally treated with CPAP.

In this study, the authors performed a maintenance of wakefulness test (MWT) after three months of CPAP use, which measures a patient's ability to stay awake throughout the day. The Federal Aviation Administration uses the MWT results in pilots with OSA to determine if the CPAP is working such that they can fly safely. Interestingly, there was no improvement in the MWT results even in patients who were optimally compliant with CPAP.

The authors measured subjective sleepiness with a common question and answer scale called the ESS. Finally, the measured daytime mental functioning with subjective (question and answer tests) and objective computer testing.

The ESS scale showed improvement with more CPAP use. However, even if the patient used CPAP 7 hours per night, 19% of compliant OSA patients had an elevated ESS, indicating persistent sleepiness.

Daytime mental function levels varied considerably in OSA patients before treatment. There was a predictable improvement in some patients who used CPAP on some of the measures of daytime functioning, but not in everyone, including those who used the CPAP an optimal amount.

The results of this study are consistent with other studies' results and with my clinical experience. Not everyone gets all the way better with regular CPAP use. There are other reasons to use CPAP consistently, though, including cardioascular protection.

Another intersting point brought up by the authors was whether the MWT is the most appropriate measure of a pilot's ability to fly safely with regards to EDS. Perhaps these pilots should have a different daytime sleepiness measure such as the MSLT, which is used to diagnose narcolepsy.

Tuesday, January 11, 2011

Generalized Anesthesia is not Sleep

There is an article in the December 30th edition of the New England Journal of Medicine that concludes that general anesthesia is a drug-induced coma and not sleep. Anesthesiologists apparently know this and tell patients they are putting them to sleep because they know that telling patients they are putting them in a coma might be too scary.

Three neuroscientists came to the conclusion after reviewing the data. This is interesting because the data show that coma and the effect of anesthesia are similar. By studying the drug-induced coma of anesthesia, researchers might learn more about how to help patients recover from a coma.

Even though anesthesia may not be sleep, some of my patients with insomnia remark that the best sleep they ever got was under general anesthesia. Studying those individuals would be interesting too. Remember, Michael Jackson died in part because of using general anesthesia to induce 'sleep' in his home. Very dangerous.

Sunday, January 2, 2011

Your Brain and Sleep Apnea



There is an online article in the American Journal of Respiratory and Critical Care Medicine from October 2010 that links deficits in thinking and brain cells to obstructive sleep apnea (OSA). Apparently this study provides the first evidence that brain cell loss occurs in OSA and that treatment can reverse some of those changes.

Researchers showed that patients with OSA before treatment had impairments in thinking, mood, and had excess sleepiness (as might be expected). Before treatment, the OSA patients had brain cell loss in regions thought responsible for abstract reasoning, executive functioning (planning, organizing, etc), alertness.

The researchers speculate that the areas of the brain affected by OSA get damaged when blood oxygen levels drop too low (called hypoxia). I wonder if there is more to it - in addition to hypoxia, OSA causes surges in adrenaline that occur when OSA patients arouse from sleep to open their airway. This adrenaline surge could spike blood pressure which could do damage to the brain over time. Either way, OSA is bad for the brain.

Saturday, January 1, 2011

Tongue Zapper

There is an article in the local paper about a new way to treat obstructive sleep apnea (OSA). Researchers are working on an implantable device that would send electrical signals to the nerve that controls the tongue. Tongue collapse onto the back of the throat can contribute to airway closure and OSA. By stimulating the tongue nerve (called the hypoglossal nerve) with electrical impulses, the tongue can be forced to contract, and consequently staying away from the back of the throat during sleep.

The article mentions three companies working on this implantable device. Inspire Medical Systems is planning to enroll 100 OSA patients in a study in the U.S. and Europe to see if the hypoglossal nerve stimulation works. ImThera Medical says it hopes to begin U.S. studies later next year, and Apnex Medical, has announced testing.

This type of treatment is exciting to me, as it could be used as a stand-alone therapy, replacing CPAP in some patients. It also might be part of a combination therapy with an oral applliance and/or upper airway surgery.