September 07, 2012

WCSA2012 - #6 – Faces of sleep apnea

The last full day of the World Congress on Sleep Apnea began with a presentation by Dr. Josep Maria Montserrat of Barcelona with another vexing issue in sleep medicine – auto-titrating positive airway pressure devices. His presentation outlined the work he has done to understand the technology and how it can benefit the patient, particularly as a means of titrating the proper pressure to use with a PAP device.

One telling comment he made after mentioning that the algorithms for the different APAPs differ from one another and that they change from one generation of the device to the next without the manufacturer’s announcing the change. The technology has gotten ahead of the science, he said. I had heard this comment at another conference a number of years ago – it was troubling then and it remains  troubling now.
The second talk of the day, perhaps my favorite of the congress, was delivered by Dr. Meir Kryger of Yale. His talk was titled “Faces of Sleep Apnea.” Kryger has, by his count, treated 12,000 patients since 1972 when he started in the field of sleep medicine. His presentation consisted of pictures of sleep apnea patients he has treated over the years. Some of the faces were familiar typology for the OSA patients and some were not. Each image had a story and it was clear that he cared about each one. His talk reminded those present that the physical examination and the patient history are critical to getting to a diagnosis.

The congress ended without a clear statement on where the event would next be held. Pressure from the sponsors of these events to consolidate the number of sleep medicine conferences leaves the date of the next World Congress on Sleep Apnea open. Perhaps it is fitting that the last scheduled congress was held in the Eternal City, the place I call my spiritual home.
Arrivederci!

WCSA2012 - #5 - New under the sun

In an earlier post I mentioned that conferences like the World Congress on Sleep Apnea provide an opportunity to present information on work in progress. Today I add that they also serve to bring people up to date on later stages of development.

On Thursday Dr. Alan R. Schwartz, a pulmonologist from Johns Hopkins School of Medicine, provided a review of the current literature on neuromodulation of the upper airway in OSA. Currently there are three companies in various phases of clinical trials using neurostimulation of the tongue to prevent sleep apnea from occurring. The results so far are mixed, with each company reporting different levels of success.  The use of a “pacemaker” to treat sleep apnea likely will be a component of future OSA treatment. How many companies will be engaged remains to be seen.

Pediatric OSA was a significant topic area during the conference. One of most promising treatments for OSA in children is rapid maxillary expansion.  Dr. Paola Pirelli, an orthodontist who pioneered the use of RME, reported on the use of this technique.

The most interesting poster of the day, for me, added to the debate on calculating severity of sleep apnea. Prof. Andreo Larsen from Finland presented “Apnoea Load – A new supplementary index for assessing sleep.” He argued that the current measure of severity, the apnea-hypopnea index or AHI, does not take into consideration time or duration. He believes that a patient with longer apnea events (spending more time in a hypoxic state) has more severe disease than someone with the same number but of shorter duration.  He calculates the apnoea load or AL by taking the average number of apneas per hour times the average duration of apneas in minutes. The AL would be a useful supplement to the AHI to identify borderline cases.
I am confident that the field of sleep apnea research is good hands. My only worry, and it is not small, is who is dictating the direction of the work.

September 02, 2012

WCSA2012 - #4 - Sleep Apnea and Nothing but Sleep Apnea

The World Congress on Sleep Apnea provides a unique opportunity among the medical/sleep meetings I attend. This gathering exclusively addresses the condition that is my work—sleep apnea. It can be exhausting to spend so much time listening and learning on one subject, but heck . . . in this case, it is Rome.


Several of Wednesday’s presentations were particular provocative.

The first session of the day focused the thorny issue of scoring. At present there are several criteria for evaluating or scoring a sleep study.  How the study is scored can change the key measure of disease, the apnea-hypopnea Index or AHI. The presenter reviewed how two different scoring techniques, “Chicago” and American Academy of Sleep Medicine 7, could affect the estimate of prevalence of sleep-disordered breathing in the general population. Without getting into a lot of detail, suffice it to say that addressing this issue is critical to having consistency in our research.

This type of conference is also a venue for researchers to present preliminary data from their work. These “poster sessions” are occasions for researchers to get feedback positive and negative. Sometimes the work continues after this check-in. Sometimes it ends right there.

Two of these check-ins caught my attention this day – “Time- but not dose-dependent amelioration of obstructive sleep apnea by dronabinol” and “Predictive utility of a risk assessment for nonadherence to CPAP: nap index.”

The first is looking at using dronabinol, a cannabinoid medication (yup, you guessed it), to reduce OSA. Interestingly this component of marijuana affects the vagal nerve, which among things works on the muscles involved in the control of breathing. This research still in its early phases is exploring the possibility of a drug that could help treat sleep apnea, either alone or in conjunction with other treatments.

The second involves the use of a risk assessment tool that helps predict whether a patient prescribed PAP therapy will have difficulty adjusting to the treatment. The value of this tool will be better  identification of people who may need special attention early in treatment.

Another feature of these meetings is “industry-sponsored” presentations. Companies often present data about their products as well as details on what they produce. I was particularly interested in the Philips/Respironics offering titled “CPAP Compliance.” The first talk by Dr. Luigi Ferini Strambi of Milan – “What is the rationale for using CPAP and how much use is enough?”— was certainly a provocative title. Ferini provided a comprehensive review of the current medical literature on the benefits of using PAP therapy on cardiovascular, metabolic, and mental health issues.  As to the question of how much use is enough – the more the better.


This is an exciting time to be involved in the field of sleep medicine, and I am pleased to serve as a conduit conveying information to patients.