Oropharyngeal Exam Predicts Severity of Sleep Apnea

Steven Fox

October 17, 2011

October 17, 2011 — A simple oropharyngeal exam can provide key information regarding the severity of obstructive sleep apnea syndrome (OSAS), according to results from a study of more than 300 patients that was carried out in Spain.

The study appears in the October issue of the Archives of Otolaryngology Head and Neck Surgery.

Although the pathogenesis of OSAS has not been definitively established, it is generally blamed on partial or complete obstruction of the upper airway with involvement of the oropharynx.

However, senior and corresponding author Christian Domingo, MD, PhD, from the Pneumonology Service, Hospital Parc Tauli, Barcelona, Spain, and colleagues note that in spite of recent medical advances, up to 80% of patients remain undiagnosed.

"To some extent, this is due to the fact that patients are not aware of the disease, but the logistic difficulties of diagnosis should also be borne in mind," they write. They add there is no simple, fast physical exam that can facilitate screening of patients to assess whether they have sleep apnea and, if so, how severe it may be.

With that in mind, the researchers designed a prospective, single-center, cross-sectional study of 301 consecutive patients who had been referred to a sleep laboratory for diagnosis and treatment of OSAS. The mean age of patients was 51 years, and just over 70% were men. Their mean body mass index (BMI) was 29.8 kg/m2.

The study was aimed at validating the clinical significance of an easy-to-assess clinical exam that included Friedman tongue position (FTP), tonsil size, and uvula size, along with other clinical characteristics (sex, age, BMI, cervical perimeter, nasal flow) to assess their relative utility in predicting the apnea-hypopnea index.

FTP grade 3

The FTP procedure involves having the patient open their mouth widely without protruding their tongue. Based on the relative appearance of the palate, the patient is assigned a grade from 1 to 4:

  • Grade 1 allows the observer to visualize the entire uvula and tonsils or pillars.

  • Grade 2 allows visualization of the uvula but not the tonsils.

  • Grade 3 allows visualization of the soft palate, but not the uvula.

  • Grade 4 allows visualization of the hard palate only.

Tonsil size was also graded from 0 to 4:

  • Size or grade 0 means the tonsils have been removed.

  • Size or grade 1 implies the tonsils are hidden within the fossa.

  • Size or grade 2 implies the tonsils extend to the pillars.

  • Size or grade 3 tonsils extend beyond the pillars but stop short of the midline.

  • Size or grade 4 denotes tonsils that extend to the midline, almost touching each other.

Once the investigators had determined both the FTP and tonsil size of the patients, they combined those 2 scores to stage the patients:

  • Stage I disease was defined as having a palate position of 1 or 3, tonsil size 3 or 4, and BMI of less than 40 kg/m2.

  • Stage II was defined as a palate position of 1 or 2 and a tonsil score of 0, 1, or 2, or palate position 3 and 4, with tonsil size 3 or 4 and a BMI less than 40 kg/m2.

  • Stage III disease was defined as palate position 3 or 4 and tonsil size 0, 1, or 2.

Patients with a BMI of more than 40 kg/m2 were classified as stage III disease.

The researchers reported that in 94.0% of the patients, the apnea-hypopnea index (AHI) was at least 5.0/hour.

About 74% of the patients had FTP scores of 2 or 3. Another 14% had an FTP of 1, and 11.6% were assigned an FTP of 4.

Of the 6.0% of patients who were deemed to have a normal apnea-hypopnea index, 16 had FTP scores of 1, and 2 had a score of 2.

Tonsil size scores (P = .005), uvula scores (P = .003), cervical perimeter (P < .001), nasal flow at 150 Pa (P = .02), BMI (P < .001), and age (P = .007) were all related to OSAS severity.

"Curiously, AHI values in patients who had undergone tonsillectomy were higher than in those with a [tonsil size] score of 1 and quite similar to those with a [tonsil size] score of 2," the authors note.

They said most of those patients were classified as having moderate to severe OSAS. "Fifty-two (67%) had an AHI value higher than 15.0/hour, and only 4 (7.6%) had an AHI value lower than 5.0/hour. Uvula scores of 2 and 3 were found in 90.7% of the population."

Using a multiple regression model, the authors note, only the FTP score demonstrated a relevant relationship to OSAS severity.

They conclude: "First, since the FTP score is almost the only parameter related to OSAS severity, a simple oropharyngeal examination can provide key information on this issue. Second, tonsillectomy does not seem to protect against development of OSAS."

Dr. Domingo has received lecture fees from Glaxo Smith-Kline, Astra-Zeneca, Novartis, Boehringer, Menarini, Bayer, and Esteve. Another author has organized courses and received lecture fees from Schering-Plough and Merck Sharp & Dohme.

Arch Otolaryngol Head Neck Surg. 2011;137:990-996. Abstract

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