Nasal patency and the effectiveness of nasal continuous positive air pressure in obstructive sleep apnea

Understanding potential associations between anatomic and other factors in OSA severity

PURPOSE

The aim of this prospective study was to investigate associations between nasal/oropharyngeal structures and a range of factors including age, gender, daytime sleepiness, and body mass index (BMI).

METHODS

Patients with OSA were prospectively selected as research participants in rhinomanometric analysis as well as for otolaryngological evaluation. Participants were grouped as follows according to their apnea/hypopnea index (AHI) scores: no OSA (AHI < 5), mild OSA (5 ≤ AHI ≤ 15), moderate OSA (15 ≤ AHI < 30), and severe OSA (AHI ≥ 30). One-way analysis of variance (ANOVA), Kruskal-Wallis H, and Mann-Whitney U tests were performed to assess OSA severity in terms of the relationships between nasal resistance (NR) and anthropometric indices (body mass index (BMI), Friedman tongue position (FTP)), age, and gender.

RESULTS

The study cohort of 177 men and 81 women ranged in age between 21 and 76 years, with BMI ranging from 23 to 45. In total, 37 patients were simple snorers (AHI < 5), and 221 patients were diagnosed with OSA. There was no significant difference among the AHI groups in terms of nasal volume (Vol05) (p = 0.952), mean flow (p = 0.778), and mean NR total (p = 0.723). A statistically significant difference was found between the AHI groups in terms of mean BMI and median FTP scores (p < 0.001).

CONCLUSION

This study provides evidence that that the oropharyngeal region (oropharynx, tongue, and vallecula) is a more important determinant of OSA severity than the nasal region.

Nasal Obstruction and Sleep-Disordered Breathing: A Study Using Acoustic Rhinometry

Background

The relationship between nasal airway function and sleep-disordered breathing (SDB) remains unclear. Although correction of nasal obstruction can significantly improve nighttime breathing in some patients, nasal obstruction may not play a role in all cases of SDB. An effective method of stratifying these patients is needed. Acoustic rhinometry (AR) is a reliable, noninvasive method of measuring the dimensions of the nasal airway.

Methods

In 44 patients, we performed acoustic rhinometric measurements of nasal airway cross-sectional area, followed by hospital-based polysomnography and nasal continuous positive airway pressure (nCPAP) level titration. We compared anatomic nasal obstruction to perceived nasal obstruction, as well as respiratory distress index and nCPAP titration level, using the Pearson correlation and multiple linear regression analysis within body mass index groups.

Results

Perceived nasal obstruction correlated significantly with objective anatomic obstruction as measured by AR (r = 0.45, p < 0.01). For certain subgroup analyses inpatients with a body mass index below 25, AR measurements correlated significantly with both nCPAP titration pressure (r = 0.85, p < 0.01) and respiratory distress index (r = 0.67, p = 0.03).

Conclusion

Nasal airway function may be a significant component of SDB in some patients, perhaps playing a larger role in patients who are not overweight. The best responders to nasal surgery for SDB may be nonoverweight patients with nasal obstruction. AR along with nasal examination may be helpful in the evaluation and treatment of the SDB patient.

Initial adherence to autotitrating positive airway pressure therapy: influence of upper airway narrowing

Objectives

There is still debate concerning the reason for the high initial failure rate of positive airway pressure (PAP) treatment. The objective of this study is to investigate the factors of the initial adherence to PAP, with an emphasis on the role of upper airway narrowing.

Methods

The patients were divided into two groups according to the continuation of therapy within the first three months of treatment. The demographic and polysomnographic findings, the minimal nasal cross sectional area (MCA), the degree of palatine tonsilar hypertrophy (PTH) and the modified Mallampati grade of the oropharynx inlet (Orophx) were compared between the study groups.

Results

Among 36 patients, 23 continued the auto-adjusting positive airway pressure (APAP) therapy (the adherent group) and 13 discontinued APAP within three months (the non-adherent group). The apnea-hypopnea index (AHI) was significantly higher in the adherent group than in the non-adherent group (P<0.001). The AHI distributions of the two groups are extremely different. Thirteen of the 23 patients in the adherent group had an AHI of more than 60/hr, while none of the patients in the non-adherent group had an AHI of more than 60/hr. In the patients with an AHI from 15 to 60/hr, the MCA at the wide side of the nasal cavity and the sum of the MCAs of both sides were significantly larger in the adherent group than those values in the non-adherent group (P=0.004). The PTH and the Orophx were not significantly different between the two groups.

Conclusion

AHI is a definite significant factor of adherence to APAP therapy. The dimension of the nasal cavity has an influence on initial APAP adherence in the patients who have a not too high level of AHI.

Snoring - the role of the laryngologist in diagnosing and treating its causes

According to various data, snoring may affect about 2 billion people worldwide, with about 8 million adult people in Poland being estimated to snore. Apart from being disturbing for other people, it brings about a measurable risk for the patient, which results from transient anoxia. As a consequence, it may increase the risk of arterial hypertension, myocardial infarction, cerebral stroke and impotency, as well as mental disturbances like depression or anxiety states. The physician a snoring patient may consult in the first instance is the laryngologist. He determines whether upper airway obturation (in contrast to central sleep apnea) is dealt with, and takes a decision about treatment method, or redirects the patient to another specialist. In this paper, the position of a laryngologist in the diagnosis and treatment of snoring is presented. The material consisted of patients presenting with this problem at the otolaryngology department. The proceedings with patients in the admission office setting were described as well as qualification methods for further medical and operative treatment. A review of the applied procedures was made, in particular allowing for the most recent therapeutic methods.

Nasal patency measured by acoustic rhinometry in East Asian patients with sleep-disordered breathing

BACKGROUND

Nasal obstruction is thought to be a risk factor in obstructive sleep apnea (OSA). However, the relationship between nasal patency and sleep-disordered breathing remains controversial. The aim of this study was to examine the association between acoustic rhinometry findings and results of overnight polysomnography.

METHODS

From February to October 2003, patients who underwent overnight polysomnography assessment were enrolled in the study. We excluded patients who were under 20 years old, had severe deviated nasal septum, had previously received nasal or palatal surgery, or could not complete sleep test or acoustic rhinometry examination. Participants' basic data including age, gender, neck circumference, and body mass index (BMI) were collected. All participants received acoustic rhinometry before overnight polysomnography. The results along with sleep-test outcomes were recorded and analyzed.

RESULTS

A total of 87 patients were included in this study. Patients with respiratory disturbance index (RDI) less than 5/h (n = 26) or with RDI of 5-30/h (n = 28) tended to have larger minimal cross-sectional area (MCA) compared with those of patients whose RDI was more than 30/h (n = 33) (P = 0.001). A stepwise multiple regression analysis showed that BMI, male gender, and MCA were contributing factors in RDI. The R2 value of the multiple regression analysis was 0.406.

CONCLUSION

Patients with severe OSA tended to have smaller MCA when compared with patients with RDI less than 30/h. However, it was hard to predict whether patients had OSA from acoustic rhinometry examination.

Impact of impaired nasal breathing on sleep-disordered breathing

OBJECTIVE

The role of the nose and its importance in the development and severity of sleep-disordered breathing (SDB) is still a matter of discussion. In the first part of this study, often-controversial data and theories about the nose are reviewed concerning its influence on the pathophysiology of SDB and to interpret certain clinical findings connected with impaired nasal breathing. In the second part, the effectiveness of some nonsurgical and surgical therapies is evaluated.

METHOD

A worldwide literature research (Medline) was the basis for this review.

RESULTS

The study of the literature on nasal resistance and clinical findings about the effects of incomplete or complete nasal blockage, particularly in comparison of healthy persons and persons with SDB, allows the assumption of the existence of two different groups of responders: a larger group where the importance of the nose for SDB is negligible and a smaller group where the influence of the nose on SDB is crucial. The same seems to hold true for the responses to nonsurgical and surgical treatments with only a few surgical results available in the literature. While the success rate of nasal surgery for patients with obstructive sleep apnea, for instance, seems to be less than 20%, the normalization of nasal resistance often leads to a positive impact on the well-being and the sleep quality of these patients. However, because criteria to identify responders are lacking, the prediction of success of any treatment for the individual with SDB is not possible.