Altered positional regulation of nasal patency in patients with obstructive sleep apnoea syndrome

Effects of sitting, supine, and prone postures on nasal patency in individuals with obstructive sleep apnea syndrome

BACKGROUND

Studies have found that in healthy individuals without nasal disease, changes in posture cause an increase in nasal resistance, especially in the prone posture. Many patients with obstructive sleep apnea syndrome (OSAS) sleep in a prone posture, but no studies have examined the effect of this change in posture on nasal resistance in patients with OSAS. Therefore, we conducted this study to investigate this posture-related physical phenomenon in individuals with OSAS.

METHODS

We evaluated the nasal patency of 29 patients diagnosed with OSAS using the visual analog scale (VAS), acoustic rhinometry, and video-endoscopy in the sitting, supine, and prone postures.

RESULTS

In the OSAS group, both supine and prone postures significantly influenced subjective nasal blockage and led to a notable reduction in the minimal cross-sectional area (mCSA) as determined by acoustic rhinometry, compared to the sitting posture. The prone posture exhibited a more pronounced effect than the supine posture. Endoscopic evaluations further revealed increased hypertrophy of the inferior turbinate in the supine posture for the right nasal passage and the prone posture for the left. However, no significant differences were observed between the prone and supine postures.

CONCLUSION

In OSAS patients, nasal resistance significantly increased in supine and prone postures compared to sitting, with the prone posture showing a greater effect. Clinicians should consider a patient's habitual sleep posture and the effects of postural changes when assessing OSAS severity and devising treatment plans.

LEVEL OF EVIDENCE: 4

Nasal Patency Across Seated, Supine, and Recumbent Postures in Individuals With and Without Allergic Rhinitis

Objectives: This study aimed to investigate the effects of seated, supine, and recumbent postures on nasal resistance in individuals with allergic rhinitis (AR) and healthy controls, which has not been investigated in the past. Methods: A visual analog scale (VAS) assessed subjective nasal obstruction, while acoustic rhinometry and video endoscopy provided objective measures. Sixty participants, comprising 30 AR patients and 30 healthy controls, were evaluated across 4 postures without decongestion: seated, supine, left recumbent, and right recumbent. Results: In patients with AR, we noted no significant changes in subjective nasal blockage under various postures (all P > .18). However, significant reductions of minimal cross-sectional area (mCSA) were found (seated vs supine, P = .014; seated vs left recumbent, P = .001; seated vs right recumbent, P < .001) and significant increases in the inferior turbinate hypertrophy were observed on the dependent side of the nose when in recumbent posture (right nose: seated vs right recumbent, P = .013; left nose: seated vs left recumbent, P = .003). On the contrary, healthy controls experienced increased subjective nasal obstruction (VAS scores: seated vs supine, P < .001; seated vs left recumbent, P = .003; seated vs right recumbent, P < .001), reductions in mCSA (seated vs supine, P = .002; seated vs right or left recumbent, both P = .001), and increased inferior turbinate hypertrophy on the dependent side of the nose (right nose: seated vs right recumbent, P = .003; left nose: seated vs left recumbent, P = .006). Conclusions: Healthy controls reported better nasal patency when shifting from supine or recumbent to more upright or less gravity-dependent seated postures, which was further supported by objective examinations. On the contrary, despite patients with AR not subjectively perceiving increased nasal patency while adopting more upright postures, objective evaluations demonstrated an improvement in their nasal airflow in these less gravity-dependent postures.Level of Evidence: 4.

Nasal Patency in Sitting, Supine, and Prone Positions in Individuals with and without Allergic Rhinitis

(1) Background: Physiological changes in nasal patency in response to posture contribute to sleep-related problems. Previously, we reported that the supine and prone positions cause a significant decrease in nasal patency in subjective and objective assessments of healthy individuals. Therefore, we conducted a study to evaluate the effect of posture on nasal patency in patients with allergic rhinitis (AR); (2) Methods: The present study comprised 30 patients diagnosed with AR and 30 healthy subjects without nasal disease (non-AR). Changes in nasal patency were evaluated in the sitting, supine, and prone positions. We used the visual analog scale to evaluate subjective nasal blockage. Acoustic rhinometry and endoscopy were used to objectively measure changes in nasal patency; (3) Results: In the non-AR group, the prone position had a significant effect on subjective nasal blockage compared with the sitting position, with significant decreases in the minimal cross-sectional area (mCSA) measured by acoustic rhinometry. Furthermore, endoscopy demonstrated a significantly increased inferior turbinate hypertrophy in the non-AR group. In the AR group, there was no statistical difference in subjective nasal blockage symptoms between the different positions. However, in objective examinations (acoustic rhinometry and endoscopy), the prone position showed significantly decreased nasal patency; (4) Conclusions: In patients with AR, subjective nasal blockage did not significantly increase in the supine or prone position. Endoscopy demonstrated increased inferior turbinate hypertrophy in supine and prone positions resulting in a significant reduction in nasal cavity mCSA, indicating an objective reduction in nasal patency.

Analysis of nasal resistance regulation mechanism during postural changes in patients with obstructive sleep apnea by measuring heart rate variability

STUDY OBJECTIVES

Changes in nasal resistance (NR) during postural changes are influenced by venous filling pressure and autonomic nervous system mediation, and heart rate variability (HRV) can reflect changes in the autonomic nervous system. This study aimed to explore the regulatory mechanisms of NR in patients with obstructive sleep apnea (OSA) during postural changes.

METHODS

Healthy controls (apnea-hypopnea index < 5 events/h) and patients with OSA were recruited. NR and electrocardiogram data were collected in sitting, supine, left-lateral, and right-lateral postures. HRV parameters were obtained by analyzing the electrocardiogram data from each posture. Subgroups were divided according to sitting-supine NR changes, and HRV parameters were compared between different postures and groups/subgroups.

RESULTS

In total, 34 healthy controls and 39 patients with OSA (mean apnea-hypopnea index 34.34 ± 22.44 events/h) were recruited. During sitting-supine postural changes, the NR increased in the control group but did not change significantly in the OSA group. None of the autonomic nervous system-related HRV parameters changed significantly. After the groups were divided into NR-elevated and NR-unchanged subgroups, sympathetic activity-related HRV parameters were higher in the NR-unchanged subgroup but only statistically significant in the OSA group. When comparing the left and right postures, there was no significant change in NR; however, the OSA group had lower parasympathetic activity-related HRV parameters when in the right posture.

CONCLUSIONS

During postural changes from the sitting to supine positions, the total NR increases, and this increment is smaller in patients with OSA. This is likely due to overregulation of sympathetic activity, which may occur in patients with OSA.

CITATION

Shi Y, Lou H, Wang H, et al. Analysis of nasal resistance regulation mechanism during postural changes in obstructive sleep apnea patients by measuring heart rate variability. J Clin Sleep Med. 2023;19(4):643-650.

Surgical correction of nasal obstruction in obstructive sleep apnea improves CPAP outcomes and compliance

BACKGROUND

Although continuous positive airway pressure (CPAP) therapy curtails most of the negative impacts of obstructive sleep apnea (OSA), its efficacy is limited by its low long-term adherence. Nasal obstruction contributes to OSA pathophysiology and necessitates high CPAP titration pressures which reduce CPAP compliance.

AIM

This study aims at elucidating the outcomes of surgical correction of nasal obstruction in patients intolerant to CPAP therapy.

METHODS

Forty-nine patients with severe OSA intolerant to CPAP secondary to surgically correctable nasal obstruction were operated upon. Patients were evaluated preoperatively and at least 3 months after the surgical intervention. Subjective assessment entailed the Nasal Obstruction Symptom Evaluation score (NOSE) and the Epworth Sleepiness Scale (ESS). Objectively the patients were assessed by acoustic rhinometry and standard polysomnography.

RESULTS

Nasal surgical intervention resulted in an a statistically significant decrease in the mean NOSE score, ESS and optimal CPAP titration pressure. In addition, the minimal cross-sectional area (MCA1&2) increased significantly postoperatively. There was a positive correlation between the improvement in NOSE score as well as the MCA1& 2 and the postoperative decrease in CPAP titration pressure. Surgical correction of nasal obstruction improved CPAP outcomes and compliance in all patients.

CONCLUSIONS

Nasal surgery in OSA objectively assessed by acoustic rhinometry improved nasal obstruction with a resultant decrease in the CPAP pressure requirements. Given that lower CPAP pressures improve adherence to CPAP therapy, surgical alleviation of nasal obstruction should be considered a crucial intervention in the management armamentarium of OSA.

Effects of Supine and Prone Positions on Nasal Patency in Healthy Individuals

OBJECTIVES

Supine position reduces nasal patency compared with that in the sitting position; however, data on the effects of prone position on nasal patency is lacking.

METHODS

We assessed the nasal patency of 30 healthy individuals without upper respiratory tract disorders by using visual analog scale (VAS) score and acoustic rhinometry in 7 positions: sitting; frontal, right, and left supine; and frontal, right, and left prone.

RESULTS

According to the VAS scores, compared with that in the sitting position, both the supine and prone positions significantly increased subjective nasal obstruction (P < .001). The prone position had a more significant effect than did the supine position (P = .017). The results of minimal cross-sectional area measured through acoustic rhinometry demonstrated that both the supine and prone positions reduced the nasal patency significantly, but without significant differences between the effects of prone and supine positions (P = .794).

CONCLUSION

This is the first study to elucidate that the prone position can significantly reduce the nasal patency in healthy individuals through subjective and objective assessments.

LEVEL OF EVIDENCE

IV.

Total nasal airway resistance while sitting predicts airway collapse when lying down

BACKGROUND

Nasal obstruction when lying down is a common complaint in patients with chronic nasal obstruction, but rhinomanometry is typically performed in the sitting position. This study aimed to analyse whether adding rhinomanometry in a supine position is a useful examination.

METHOD

A total of 41 patients with chronic nasal obstruction underwent rhinomanometry and acoustic rhinometry, sitting and supine, before and after decongestion, as well as an over-night polygraphy.

RESULTS

Total airway resistance was measurable in a supine position in 48 per cent (14 of 29) of the patients with total airway resistance of equal to or less than 0.3 Pa/cm3/second when sitting and in none (0 of 12) of the patients with total nasal airway resistance of more than 0.3 Pa/cm3/second when sitting. After decongestion, this increased to 83 per cent and 58 per cent, respectively.

CONCLUSION

Increased nasal resistance when sitting predicts nasal breathing problems when supine. Rhinomanometry in a supine position should be performed to diagnose upper airway collapse when supine.

The Reliability and Influence of Body Position on Acoustic Pharyngometry and Rhinometry Outcomes

OBJECTIVES

The aim of this cross sectional study was to analyze the method error and reliability in acoustic pharyngometry and rhinometry and to analyze the difference between standing and sitting position in acoustic pharyngometry and rhinometry.

MATERIAL AND METHODS

The sample comprised 38 healthy subjects (11 men and 27 women) as part of a control group in another study. The subjects underwent repeated measures of acoustic pharyngometry and rhinometry in standing and sitting position. Upper airway dimensions in terms of volume, minimum cross-sectional areas (MCA) and distances were evaluated using the Eccovision® Acoustic Pharyngometer and Rhinometer. Method error and reliability were analyzed using paired t-test, Dahlberg's formula and the Houston reliability coefficient, and differences between body positions were analyzed using paired t-test.

RESULTS

There was no systematic error in the repeated measures except for the distance to MCA in the left nostril in sitting position (P = 0.041). The method error for the pharyngometry ranged between 0.001 to 0.164 cm/cm2/cm3 and the reliabity was 0.99. The method error for rhinometry ranged between 0.001 to 0.37 cm/cm2/cm3 and the reliability between 0.99 to 1. Difference between standing and sitting position was found only in the pharyngeal airway in terms of volume (P = 0.025) and mean area (P = 0.009) with smaller airway in sitting position.

CONCLUSIONS

The results indicate that acoustic pharyngometry and rhinometry are reliable methods to perform repeated measures of the upper airway dimensions especially in the standing mirror position. It may be essential to perform the measures with the patient positioned in the same body position each time.

Efficacy of a novel oral appliance and the role of posture on nasal resistance in obstructive sleep apnea

STUDY OBJECTIVES

High nasal resistance is associated with oral appliance treatment failure in obstructive sleep apnea (OSA). A novel oral appliance with a built-in oral airway has been shown to reduce pharyngeal pressure swings during sleep and may be efficacious in those with high nasal resistance. The role of posture and mandibular advancement on nasal resistance in OSA remains unclear. This study aimed to determine (1) the effects of posture and mandibular advancement on nasal resistance in OSA and (2) the efficacy of a new oral appliance device including in patients with high nasal resistance.

METHODS

A total of 39 people with OSA (7 females, apnea-hypopnea index (AHI) (mean ± standard deviation) = 29 ± 21 events/h) completed split-night polysomnography with and without oral appliance (order randomized). Prior to sleep, participants were instrumented with a nasal mask, pneumotachograph, and a choanal pressure catheter for gold standard nasal resistance quantification seated, supine and lateral (with and without oral appliance, order randomized).

RESULTS

Awake nasal resistance increased from seated, to supine, to lateral posture (median [interquartile range] = 1.8 [1.4, 2.7], 2.7 [1.7, 3.5], 3.4 [1.9, 4.6] cm H₂O/L/s, P < .001). Corresponding measures of nasal resistance did not change with mandibular advancement (2.3 [1.4, 3.5], 2.5 [1.8, 3.6], 3.5 [1.9, 4.8] cm H₂O/L/s, P = .388). The median AHI reduced by 47% with oral appliance therapy (29 ± 21 versus 18 ± 15 events/h, P = .002). Participants with high nasal resistance (> 3 cm H₂O/L/s) had similar reductions in AHI versus those with normal nasal resistance (61 [-8, 82] versus 40 [-5, 62] %, P = .244).

CONCLUSIONS

Nasal resistance changes with posture in people with OSA. A novel oral appliance with a built-in oral airway reduces OSA severity in people with OSA, including in those with high nasal resistance.

CLINICAL TRIAL REGISTRATION

Registry: ANZCTR; Title: Combination therapy for obstructive sleep apnoea; Identifier: ACTRN12617000492358; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372279.

Association of allergic rhinitis with obstructive sleep apnea: A meta-analysis

BACKGROUND

The co-existence of allergic rhinitis (AR) and obstructive sleep apnea (OSA) is a common phenomenon in clinical practice. AR has long been considered a risk factor for OSA. However, the relationship is not completely clear. Therefore, we conducted a meta-analysis to evaluate the prevalence of AR in sleep-disordered breathing (SDB) /OSA and their relationship.

METHODS

A comprehensive literature search was performed in PubMed/Medline, Google Scholar, Wiley Online Library, EMBASE, and Web of Science. Data were analyzed and pooled to estimate effect size (ES) /odds ratio (OR) with 95% confidence intervals (95%CI). Heterogeneity was quantified and evaluated by chi-squared-based Q-test and I2 test, with P < .05 and I > 50% indicating evidence of heterogeneity.

RESULTS

44 studies contained 6086 participants were included in this meta-analysis. For adults, the prevalence of AR was 22.8 (95% CI, 15.0-30.6) % in SDB and 35.2 (95% CI, 25.6-44.7) % in OSA. In children with SDB and OSA, the prevalence of AR was 40.8 (95% CI, 24.3-57.2) %, and 45.2 (95% CI, 25.4-65.0) % respectively. The odds ratios of prevalence of the SDB pediatric patients with AR was 2.12 (95%CI, 1.75, 2.57; P < .0001) times higher than that of non-SDB pediatric patients. There were no significant differences between OSA adults with or without AR in BMI (Body Mass Index), neck circumference, apnea hypopnea index (AHI) and epworth sleep scale score (ESS).

CONCLUSION

The prevalence of AR in OSA/SDB is considerably high and children with SDB suffering from a higher incidence of AR than non-SDB. OSA adults accompanied with AR do not have any influences on sleep parameters.

Subjective, anatomical, and functional nasal evaluation of patients with obstructive sleep apnea syndrome

BACKGROUND

Studies have shown a high occurrence of nasal alterations in patients with obstructive sleep apnea syndrome (OSAS), but no studies have used different methods to evaluate the nose of patients with OSAS. The objective of this study was to evaluate the nose of patients with OSAS, compare them to controls, and correlate the different methods used to evaluate the nose.

METHODS

Forty-seven patients with moderate/severe OSAS and 20 controls who were matched for gender, age, and body mass index were included. Questionnaires regarding sleep and nasal symptoms, physical examination, rhinoscopy, nasofibroscopy, nasal inspiratory peak flow (NIPF), and acoustic rhinometry (AR) measurements were performed.

RESULTS

In the OSAS group, 33 (70.2%) were male, with a mean age of 53.2 ± 9.1 years. In the control group, 13 (65%) were male, with a mean age of 53.7 ± 9.7 years. The OSAS group had a higher score on the nasal symptoms scale (p < 0.01) and a higher frequency of nasal alterations [presence of septal deviation, clinical complaints (p = 0.01) and hypertrophy of the inferior nasal turbinate (p < 0.01)]. The NIPF and AR parameters could not differentiate between the OSAS and control groups. There were no significant correlations among the different methods used to evaluate the nose. Lower NIPF values were capable of predicting higher apnea-hypopnea index scores (p = 0.007).

CONCLUSION

Clinical complaints and nasal alterations as measured by rhinoscopy and nasofibroscopy were associated with the presence of OSAS, which was not the case for the NIPF and AR parameters. The results of different evaluation methods were not correlated with each other.