Identifying Obstructive Sleep Apnoea in Patients with Empty Nose Syndrome

Abstract

Obstructive sleep apnoea (OSA) is characterised by repetitive episodes of upper airway collapse and breathing cessation during sleep. Empty nose syndrome (ENS) is a surgically iatrogenic phenomenon of paradoxical nasal obstruction despite an objectively patent nasal airway. This study aimed to investigate sleep quality and the presence of OSA in ENS patients. Forty-eight ENS patients underwent full-night polysomnography. Total nasal resistance (TNR) was determined using anterior rhinomanometry. Symptoms and quality of life were evaluated by the empty nose syndrome 6-item questionnaire (ENS6Q), Sino-Nasal Outcome Test-22 (SNOT-22), and Epworth Sleepiness Scale questionnaires (ESS). Fourteen, twelve, and fourteen patients had mild, moderate, and severe OSA, respectively. The apnoea-hypopnoea index (AHI) and the lowest SpO₂ were 23.8 ± 22.4/h and 85.9 ± 11.1%, respectively. N1, N2, N3 and rapid-eye-movement sleep comprised 30.2 ± 16.9%, 47.3 ± 15.5%, 2.1 ± 5.4%, and 20.0 ± 8.1% of the total sleep time. Body mass index, neck circumference, serum total immunoglobulin E, and ENS6Q score were significantly associated with AHI in the regression analysis. The ENS6Q scores correlated positively with AHI, arousal index, and ESS score, but negatively with TNR. ENS patients showed a high OSA prevalence and significant sleep impairment. The extent of OSA was associated with obesity levels and ENS symptom severity. The ENS6Q scores correlated negatively with nasal resistance, and positively with arousal frequency and daytime sleepiness. The recognition of individuals experiencing marked OSA and provision of appropriate intervention is critical to preventing long-term morbidity and mortality, and improving therapeutic outcomes in ENS patients.

Keywords: empty nose syndrome; empty nose syndrome 6-item questionnaire; obstructive sleep apnoea; polysomnography; sleep quality.

Figure 1

The empty nose syndrome 6-item questionnaire (ENS6Q) scores are significantly associated with the apnoea–hypopnoea index (AHI) (a), arousal index (b), and Epworth Sleepiness Scale (ESS) score (c). ENS6Q is also negatively correlated with total nasal resistance (TNR) (d). The correlations were determined using Pearson’s correlation coefficient (r) or Spearman’s correlation coefficient (r_s) if the data did not pass the normality test. (r, 0–0.2: very weak, 0.2–0.4: weak, 0.4–0.6: moderate, 0.6–0.8: strong, 0.8–1.0: very strong correlation) * p < 0.05, ** p < 0.001.

Figure 2

Receiver operating characteristic (ROC) curves to detect moderate-to-severe obstructive sleep apneoa (AHI > 15) using the variables of BMI (a), NC (b), sIgE (c), and ENS6Q (d). The optimal cut-offs for these metrics (maximizing the sum of sensitivity and specificity) are indicated.