Upper Airway Resistance Syndrome (UARS)
Upper airway resistance syndrome (UARS) was first recognized in children in 1982. The term UARS, however, was not used until adult cases were reported in 1993. The description of UARS brought clinicians’ attention to a group of patients left undiagnosed and untreated despite severe impairment. Since the original description, the syndrome has been recognized in patients with clinical and sleep study presentations different from that of obstructive sleep apnea syndrome (OSAS). Adult patients with UARS are more likely to complain of fatigue than sleepiness and not infrequently, UARS is misinterpreted as chronic fatigue syndrome.
Sleep study reveals AHI < 5, oxygen saturation > 92%, and the presence of respiratory related respiratory arousals
In the original description of UARS in 1993, the authors treated patients successfully with nasal CPAP. Since then, other therapeutic alternatives have been used. CPAP is still widely tried as the first line therapy. It is often used as a therapeutic trial to demonstrate improvement of symptoms.
Septoplasty and radiofrequency reduction of enlarged nasal inferior turbinates can be successful in treating UARS. Absence of correction of the primary cause of the abnormal breathing, such as crowded airway and narrowed jaws, will leave patients with a complaint of worsening functional symptoms and potentially may lead to the occurrence of OSAS. Therefore, it there are enlarged tonsils or adenoids, tonsillectomy and adenoidectomy would be helpful.
More and more clinicians recognize UARS as a clinical syndrome that has differential features from OSAS. It is critical to recognize the associated symptoms with UARS that are not traditionally related to OSAS. It is easy to miss UARS, but nonrecognition early in life of the syndrome and the anatomic abnormalities surrounding the upper airway responsible for its symptoms will lead to complications and perhaps even development of OSAHS.