Pressure recordings--a method for detecting site of upper airway obstruction in obstructive sleep apnea syndrome.

Polysomnography is the method of choice in diagnosis of obstructive sleep apnea syndrome (OSAS) establishing whether a patient has apneas or not. It does not, however, give any indications of where the obstructions occur. This is reflected in the limited success rate of current surgical procedures used in the treatment of this disorder. We have developed a simple method for simultaneous determination of OSAS and site of obstruction. The method implies continuously recording of pressure at different sites in pharynx. A catheter with five pressure transducers and corresponding markings is put into the pharynx through the nasal cavity and interfaced with a polygraph. Continuous pressure registrations were made in 12 patients. We have found characteristic patterns of pressure-changes which clearly indicate the level of obstruction. This may be of importance in selecting patients for further treatment.