Deviated Septum and Upper Airway Resistance Syndrome (UARS)
Yes, a deviated nasal septum can lead to Upper Airway Resistance Syndrome (UARS) by increasing nasal airway resistance, which promotes negative intraluminal pressure in the pharynx and predisposes to upper airway obstruction during sleep. 1
Pathophysiological Connection Between Deviated Septum and UARS
- Nasal obstruction from a deviated septum increases airway resistance, forcing patients to breathe through the mouth, which creates more negative intraluminal pressure in the pharynx and predisposes to pharyngeal narrowing 1
- This increased upper airway resistance during sleep can lead to the constellation of symptoms identical to OSA called "upper airway resistance syndrome" (UARS) 2
- UARS is characterized by complaints of daytime fatigue and/or sleepiness, increased upper airway resistance during sleep, frequent transient arousals, and no significant hypoxemia 2
Clinical Evidence Supporting the Connection
- Studies have demonstrated that nasal obstruction can both induce and worsen sleep-disordered breathing 1
- The most frequently observed pathologic finding in patients with sleep-disordered breathing and nasal obstruction is deviated nasal septum 1
- External nasal dilation studies have shown reduction in stage 1 sleep (a marker of disrupted sleep) and desaturation time in UARS patients, further supporting the role of nasal obstruction in UARS 3
Impact on Respiratory Function
- Deviated nasal septum and turbinate hypertrophy compromise nasal airflow and increase airway resistance, which can reduce airflow to the lungs 4
- This increased resistance can affect lung volume and function, subsequently reducing exercise tolerance 4
- Studies have shown statistically significant improvement in spirometry parameters after surgical correction of nasal obstruction 4
Diagnostic Considerations
- UARS diagnosis typically requires esophageal pressure monitoring during sleep to detect increased respiratory effort without significant oxygen desaturation 2, 5
- Typical findings on sleep study include: repetitive arousals from EEG sleep coinciding with waxing and waning of respiratory airflow pattern and increased respiratory effort 2
- Unlike OSA, UARS may have few or no obvious apneas or hypopneas with desaturation, but snoring is often a prominent finding 2
Treatment Implications
- Nasal surgery (septoplasty) can improve nasal airway patency in patients with deviated septum 1
- While nasal surgery as a single intervention is not recommended for treatment of obstructive sleep apnea syndrome (OSAS), it can improve nasal breathing and potentially reduce UARS symptoms 1
- The American Academy of Otolaryngology recommends that comprehensive medical management attempts should be documented before considering septoplasty, including duration of treatment and evidence of failure of medical therapy 6
- Nasal continuous positive airway pressure (NCPAP) is considered the most efficacious form of therapy for UARS 5
Clinical Pitfalls and Caveats
- Not all septal deviations are clinically significant - the nasal septum is off-center in approximately 80% of the general population, but only about 26% have clinically significant deviation causing symptoms 6
- Anterior septal deviation is more clinically significant than posterior deviation as it affects the nasal valve area responsible for more than 2/3 of airflow resistance 6
- Sleep position significantly affects sleep-disordered breathing in UARS, with lateral position showing lower AHI compared to supine position 3
- UARS has been associated with borderline hypertension in some patients, which can be controlled with treatment of the underlying UARS 7