Correlating Nasal Patency with Obstructive Sleep Apnea in Obese Versus Non-Obese Patients: An Acoustic Rhinometry Study

The aim of this study was to correlate nasal patency with Obstructive Sleep Apnea (OSA) in obese versus non-obese patients using Acoustic Rhinometry (AR). Eccovision® Acoustic Rhinometer equipment was used to compare nasal cross-sectional areas (CSA1,2 & 3 corresponding to nasal valve region, anterior portion of middle & inferior turbinate and posterior portion of middle & inferior turbinate respectively) and volume in age and gender matched sample divided into three groups: Group 1: Non-obese patients without OSA (25 patients, 13 males and 12 females); Group 2: Non-obese patients with OSA (25 patients, 14 males and 11 females); Group 3: Obese patients with OSA (25 patients, 13 males and 12 females). The mean nasal cross-sectional areas and volume were lower in Group 2 compared to Group 1 but statistically non-significant (P value > 0.05 for all). The mean nasal cross-sectional areas and volume were significantly lower in Group 3 as compared to Groups 1 and 2 (P value < 0.05 for all). BMI showed a statistically significant positive (direct) correlation with AHI in Groups 2 and 3 (P value < 0.05 for both). The nasal cross-sectional areas and volume showed a statistically significant negative (inverse) correlation with AHI in Groups 2 and 3 (P value < 0.05 for both). OSA diagnosed cases with high BMI may not present with an obvious nasal obstruction; the nasal patency may still be compromised due to reduced nasal lumen secondary to obesity. AR, being cost-effective and non-invasive modality; is advocated to evaluate pre-treatment nasal patency, as well as follow up evaluation to ascertain improvement after the intervention.

Two-Year follow-up with Acoustic Rhinometry in Children

Background

This is an explorative study of growth-related nasal geometry in healthy children.

Methods

A total of 88 girls and boys between the ages of 4 and 16 years were followed over a period of 2 years by acoustic rhinometry. The registrations were correlated to height at each occasion.

Results

Although both the minimal cross-sectional area and the nasal volume increased in all age groups over 7 years, large individual variations in nasal geometry led to a weak relationship with growth.

Conclusion

In the undecongested nasal cavity in children, correlation of nasal geometry makes sense for height but not for age.

The relationship between nasal resistance to airflow and the airspace minimal cross-sectional area

The relationship between nasal resistance (R) and airspace minimal cross-sectional area (mCSA) remains unclear. After the introduction of acoustic rhinometry, many otolaryngologists believed that mCSA measurements would correlate with subjective perception of nasal airway obstruction (NAO), and thus could provide an objective measure of nasal patency to guide therapy. However, multiple studies reported a low correlation between mCSA and subjective nasal patency, and between mCSA and R. This apparent lack of correlation between nasal form and function has been a long-standing enigma in the field of rhinology. Here we propose that nasal resistance is described by the Bernoulli Obstruction Theory. This theory predicts two flow regimes. For mCSA>Acrit, the constriction is not too severe and there is not a tight coupling between R and mCSA. In contrast, when mCSAAcrit (estimated to be 0.37cm(2)), this theory suggests that airway constrictions are rarely an exclusive contributor to nasal resistance, which may explain the weak correlation between mCSA and subjective nasal patency.

The Evaluation of Relationship Between Body Mass Index and Nasal Geometry Using Objective and Subjective Methods

INTRODUCTION

It is known that obesity causes obstructive sleep apnea syndrome by increasing upper airway resistance. Also, obese patients are admitted to the ear, nose, and throat clinic very often because of nasal obstruction complaint. The aim of this study is to identify the change and relation among body mass index (BMI), nasal resistance, reduction in nasal ariflow, nasal anatomy, and patients' subjective complaints.

MATERIAL AND METHOD

A total of 67 patients admitted to our clinic between August 2013 and January 2014 were included in the study.The study group comprised 33 patients who had a chief complaint-nasal obstruction and the other group consisted of 34 patients who had no complaint and nasal pathology. Both the groups were checked with acoustic rhinometry (AR), active anterior rhinomanometer, nasal obstruction symptom evaluation (NOSE), and visual analog study (VAS) questionnaire.

RESULTS

There is a significant statistical correlation between the body mass increase and VAS and NOSE score increase (P < 0.05). But the authors did not find any statistically significant relation between BMI and total inspiratory and expiratory MR and MF measured by anterior active rhinomanometer and left and right nasal cavity MCA, and volume measured by acoustic rhinometery (P > 0.05).

CONCLUSIONS

Contrary to belief, obesity does not change the nasal resistance, airflow, and anatomy but it can cause subjective nasal complaints.

The Relation Between Body Mass Index and Nasal Airflow

BACKGROUND

Nasal obstruction and complaints are common attendance causes in otorhinolaryngology clinics. Obese patients are especially more vulnerable for these complaints. There is not enough data about nasal resistance and weight.

PATIENTS AND METHODS

One hundred ten patients who had no nasal complaint and nasal pathology were investigated by peak nasal inspiratory flow meter, nasal symptom evaluation scale (NOSE), and visual analog scale (VAS) calculation.

RESULTS

According to the statistical analyses among the BMI groups, there is no significant difference detected. Peak nasal inspiratory flow values highly correlated with height. Height correlated with VAS and weight correlated with NOSE scores. VAS score highly correlated with NOSE score. Also, there is a negative statistically significant correlation between BMI and nasal congestion index.

CONCLUSION

All these data show that there is no relation between BMI and nasal resistance, and although the nasal congestion cycle is preserved in all BMI groups, nasal congestion index is decreased when the weight is raised.

Measurements of nasal airflow and patency: a critical review with emphasis on the use of peak nasal inspiratory flow in daily practice

Objective measures can be used to assist the clinician to diagnose and treat nasal obstruction and also to quantify nasal obstruction in research. Objective measurements of nasal obstruction are as important as objective measurements of lung function. peak nasal inspiratory flow (PNIF), acoustic rhinometry (AR) and rhinomanometry (RM), with their specific peculiarity, assess different aspects of nasal obstruction. From the studies available in the literature, it seems that these methods roughly correlate with each other and that all of them can be alternatively utilized very well in research as well as in clinical practice. This review describes the various methods that can be used to measure nasal patency, airflow and resistance, mainly peak nasal inspiratory flow, rhinomanometry and acoustic rhinometry. PNIF has been demonstrated to be reproducible and as good an indication of objective nasal patency as formal rhinomanometry and has the advantage to be cheap, simple and suitable for serial measurements and for home use even in the paediatric population. PNIF normative data are available for children, adults and elderly subjects, and the availability of unilateral PNIF normal values allows evaluation of nasal sides separately. Just as in the lower airways, objective and subjective evaluation gives different information that together optimizes the diagnosis and the treatment of our patients. We argue that PNIF should be used regularly in every outpatient clinic that treats patients with nasal obstruction.

Is nasal cavity geometry associated with body mass index, height and weight?

It has been reported that nasal airflow rate and pressure increased with increasing body mass index (BMI). The purpose of this study is to determine if with an increased BMI, the nasal cavity geometry as measured by acoustic rhinometry (AR) increased in healthy adult Singaporeans. This is a population based study. Seventy-three healthy volunteers, 44 males and 29 females aged 18-64 years (mean 34.9 years) were selected. Their BMI was calculated from height and weight measurements. AR was used to measure the minimum cross-sectional area 1-5 cm from the nostril, cross-sectional area at 3.3 and 4 cm and volume 1-5 cm from the nostril of the nasal cavity. There was no statistically significant correlation between BMI, height and weight with all AR measurements. Our study demonstrates that nasal cavity geometry is not affected by increasing BMI, as well as height and weight individually, of healthy adult Singaporeans. Our study indicates that subject with obesity is potentially facing a long-term physiological risk for insufficient air-exchange, or burden of increasing the respiratory rate and/or volume of each breath.

Correlation between nasal resistance and different acoustic rhinometry parameters in children and adolescents with and without allergic rhinitis

Acoustic rhinometry and rhinomanometry are important tests used to assess nasal function. The degree to which the parameters of these tests are correlated is yet to be established.

Objective

This paper aimed to study the correlations between nasal resistance (NR) and acoustic rhinometry parameters in children and adolescents with allergic rhinitis and controls.

Method

Twenty patients with allergic rhinitis and 20 controls were enrolled. NR, volumes (V4, V5, V2-5), and minimal cross-sectional areas (MC1, MC2) were measured in three moments: baseline, after induction of nasal obstruction and after topical decongestant administration.

Results

Patients with allergic rhinitis had significant correlation between NR and all volumes (V5: r = -0.60) and with MC2. Among controls, MC1 was the parameter with the strongest correlation with NR at baseline (r = -0.53) and after decongestant administration. In the combined analysis, V5 had the highest correlation coefficients at baseline (r = -0.53), after obstruction (r = -0.58) and after decongestant (r = -0.46).

Conclusions

Our data showed that NR and acoustic rhinometry parameters have negative and significant correlations. Nasal volumes are, in general, better correlated than minimal cross-sectional areas. V5 was the parameter with the highest correlation in the rhinitis group and in the combined analysis.

Intersession repeatability of acoustic rhinometry measurements in healthy volunteers

Objectives

Acoustic rhinometry is a rapid, reliable and non-invasive technique for the evaluation of conditions associated with impaired nasal patency. This study aimed to examine the intersession repeatability of acoustic rhinometry measurements of unilateral and combined nasal parameters in a group of healthy volunteers.

Methods

Twenty healthy volunteers were studied. In each subject, acoustic rhinometry measurements were performed on five consecutive days, with multiple recordings. Five clinically relevant parameters were measured in each session and the intersession repeatability of these measurements was expressed in terms of mean coefficient of variation, intraclass correlation coefficient and inter-item correlations.

Results

Intraclass correlation coefficients showed a high, and greater repeatability over time for all the combined (mean) values compared to the unilateral values. All intraclass correlations for combined values were ≥0.80 confirming almost perfect agreement. All intraclass correlations and inter-item correlations were associated with P<0.001. The mean coefficient of variation was low (<10%) for all but the proximal minimum cross sectional area (MCA1) measurements.

Conclusion

Acoustic rhinometry provides highly repeatable measurements of nasal patency, which is best for combined (mean) nasal parameters. This property makes it suitable for use in the diagnosis and follow-up of conditions associated with nasal obstruction, either structural or functional.

Video-rhino-hygrometer: a new method for evaluation of nasal breathing after nasal surgery

BACKGROUND

Nasal obstruction is one of the most frequent symptoms in the ear, nose, and throat (ENT) setting. It can be evaluated either subjectively or objectively. In a subjective way, a visual analog scale (VAS) and the Sino-Nasal Outcome Test 20 (SNOT 20) can rapidly quantify the degree of obstruction, whereas the most commonly used objective methods are nasal endoscopy and active anterior rhinomanometry (AAR). It is still a matter of controversy to what extent the sense of nasal obstruction is associated with objective measures for nasal space and airflow. The aim of the study was to evaluate nasal breathing before and after functional nasal surgery by video-rhino-hygrometer (VRH) comparing the results with widely accepted methods.

METHODS

Twenty patient candidates for septoplasty and inferior turbinate reduction were included in the study. SNOT-20, VAS, nasal endoscopy, and AAR were analyzed and compared with VRH values.

RESULTS

Before surgery VRH showed variability of nasal respiratory flow between individuals and between nostrils. After surgery we had an increase (p < 0.05) of airflow in both nostrils. VRH data were found to be correlated with VAS and SNOT-20 values (p < 0.05) both pre- and postoperatively. Despite the statistically significant correlation of AAR with SNOT-20 and VAS, no statistically significant correlation between AAR and VRH was found.

CONCLUSION

VRH provides an immediate, easy, and noninvasive assessment of nasal respiration. For these reasons it can be used, in association with rhinoscopic data and other instrumental tests, to evaluate nasal breathing in daily ENT practice.

Acoustic rhinometry, spirometry and nitric oxide in relation to airway allergy and smoking habits in an adolescent cohort

OBJECTIVE

This study aimed to analyze upper and lower airway function and the impact of smoking habits in a cohort of allergic and healthy adolescents. The influence of smoking habits on the outcomes of rhinitis and asthma is well documented, but only few reports are available showing smoke related upper airway impairment by rhinometric measurements, and none with focus on early changes in adolescents.

METHODS

A cohort followed from infancy was re-examined at the age of 18 years concerning allergy development. Acoustic rhinometry (VOL2), spirometry (FEV(1)) and measurements of nitric oxide levels from the upper (nNO) and lower airways (eNO) were performed before and after physical exercise, and smoking habits were registered.

RESULTS

Active smoking habits were reported by 4/21 subjects suffering from allergic rhinitis, by 1/4 from probable allergic rhinitis, by 0/3 subjects with atopic dermatitis and by 2/10 healthy controls. Smoking habits were reported as daily by 2 and occasional by 5 of the 7 active smokers. VOL2 did not increase in smokers after exercise as in non-smokers, resulting in a post-exercise group difference (7.3±1.1cm(3) vs. 8.8±1.5cm(3); p=0.02), and FEV(1) values were lower in smokers compared to non-smokers (89±7% vs. 98±8%; p=0.02). The nNO and eNO levels were, however, only slightly reduced in smokers. Airway allergy was discerned only in subjects with current allergen exposure by increased eNO levels compared to healthy controls (41±44ppb vs. 13±5ppb). The levels of VOL2, nNO and FEV(1) did not differentiate allergic subjects from healthy controls.

CONCLUSIONS

Low levels of tobacco smoke exposure resulted in reduced airway functions in this adolescent cohort. Acoustic rhinometry and spirometry were found to be more sensitive methods compared to nitric oxide measurements in early detection of airway impairment related to smoke exposure. A possible difference in airway vulnerability between allergic and healthy subjects due to smoke exposure remains to be evaluated in larger study groups.

EDITOR'S CHOICE: objective assessment of the nasal airway in unilateral cleft lip and palate--a long-term study

OBJECTIVE

To objectively evaluate the nasal function in adults operated on for unilateral cleft lip and palate with one-stage or two-stage palate closure.

DESIGN

The population consists of all unilateral cleft lip and palate patients born from 1960 to 1987 and treated at the Cleft Lip and Palate Center, Uppsala University Hospital, Sweden. The patients were treated according to the same protocol except for palate closure, which was performed in one stage until 1977 and in two stages thereafter. Eighty-three patients participated. Mean follow-up time after primary surgery was 32 years. An age-matched control group underwent the same examinations.

MAIN OUTCOME MEASURES

Nasal minimum cross-sectional area (cm(2)) and volume (cm(3)) were assessed (acoustic rhinometry). Airflow resistance (Pa s/cm(3)) (rhinomanometry), peak inspiratory flow (L/min) (peak nasal inspiratory flow), and number of identified odors (Scandinavian Odor Identification Test) were determined.

RESULTS

The cleft side of unilateral cleft lip and palate patients had significantly lower values for all parameters compared with controls (p < .001). No difference was found between one-stage and two-stage procedures in values for the cleft side. However, the nasal area and volume of the noncleft side were significantly larger in patients who underwent one-stage as compared with two-stage procedures (p < .05).

CONCLUSION

The nasal airway of unilateral cleft lip and palate patients demonstrates a wide range of impairments that can be quantified by objective measurements. However, the measurements used did not differentiate between patients operated on with the one-stage and two-stage procedures except for values of the noncleft side.

Pathogenetic Role of Increased Nasal Resistance in Obese Patients with Obstructive Sleep Apnea Syndrome

Background

The role of increased nasal resistance in obstructive sleep apnea syndrome (OSAS) remains controversial. The aim of this study was to examine the pathogenetic role of nasal obstruction in obese patients with OSAS.

Methods

Patients with OSAS (n = 125) at a university hospital were divided into three groups according to body mass index (BMI): nonobese (BMI < 25 kg/m2), mildly obese (25 kg/m2 ≤ BMI < 30 kg/m2), and obese (BMI ≥ 30 kg/m2). The subjects underwent nasopharyngoscopy, measurement of nasal resistance, and polysomnography.

Results

We studied 42 nonobese, 47 mildly obese, and 36 obese patients with OSAS. Among the obese, but not the nonobese and mildly obese patients, we found significant correlations between the oxygen desaturation index (ODI) and bilateral nasal resistance (BNR; r = 0.412; p = 0.013), between the ODI and unilateral higher nasal resistance (UHNR; r = 0.413; p = 0.012), and between the apnea index and UHNR (r = 0.334; p = 0.046). Multiple regression analysis incorporating all patients showed that BMI (p < 0.001) and BNR (p = 0.033) were independently related to the ODI.

Conclusions

In obese patients with OSAS, increased nasal resistance could play an important pathogenetic role in hypoxemic apnea.

Long-term effects of orthodontic therapy on the maxillary dental arch and nasal cavity

INTRODUCTION

Rapid maxillary expansion (RME) can enlarge the maxillary dental arch while increasing nasal cavity volume and nasal valve area, and decreasing upper airway resistance over time. However, the long-term effects of RME on arch morphology and nasal cavity geometry in patients treated with RME compared with the general population are unclear.

METHODS

Three-dimensional morphometic analysis and acoustic rhinometry were used to evaluate the maxillary dental arches and nasal cavities in a post-RME-treatment group (n = 25) and a control group (n = 25).

RESULTS

Palatal area and volume increased substantially after expansion and remained stable until posttreatment. Small increases in intermolar distance were not significant between the time points. Nasal airway resistance significantly decreased after RME and remained stable until posttreatment. Nasal cavity volume was stable during expansion and posttreatment. It increased significantly during expander stabilization and 9-12 months after expander removal. The minimal cross-sectional area significantly increased between the end of expansion and expander removal and remained stable until posttreatment. All measurements were comparable with those of the matched controls at posttreatment except for palatal area, which was smaller in the treatment group.

CONCLUSIONS

RME is a powerful tool to normalize most of the variables investigated. Edgewise orthodontic treatment and a retention regimen that consisted of maxillary circumferential or traditional Hawley retainers met satisfactory standards to stabilize the achieved outcomes. Future studies should include morphometric, functional, and skeletal analyses so that the effects of growth and remodeling are better elucidated.

Changes in acoustic airway profiles and nasal airway resistance after Le Fort I osteotomy and functional rhinosurgery: a prospective study

The aim of this study was to investigate the changes in nasal airways after Le Fort I osteotomy and functional rhinosurgery. 49 patients were included in this study to assess intranasal anatomical and functional changes resulting from a Le Fort I osteotomy. The data were classified according to the three-dimensional positioning of the maxilla: in group I the maxilla was impacted; in group II the maxilla was inferior; and in group III only sagittal maxillary movement was performed. Presurgical and 5 months postsurgical rhinological inspection, anterior rhinomanometry and acoustic rhinometry were carried out. Additional rhinosurgery, such as resection of the inferior concha or septoplastic intervention, was performed to avoid functional problems in nasal breathing, particularly when the maxilla was impacted. Rhinomanometric assessment showed a significant improvement in nasal breathing in the whole group and each single group. Acoustic rhinometry revealed an increase in typical cross-sectional intranasal areas. The authors conclude that concerns about the respiratory consequences of this surgical procedure appear unwarranted when functional rhinosurgery is undertaken concomitantly, particularly in patients with increased preoperative nasal airway resistance.

Effect of weight reduction on rhinometric measurements in overweight patients with obstructive sleep apnea

BACKGROUND

Elevated nasal resistance and obesity predispose to obstructive sleep apnea (OSA). Weight loss has been shown to result in an alleviation of OSA, but its effect on nasal airflow has not been studied.

METHODS

This study was a prospective, randomized, controlled study with two parallel groups. A total of 52 adult overweight patients (body mass index [BMI], 28-40 kg/m2) with mild obstructive sleep apnea (apnea-hypopnea index (AHI), 5-15) were randomized into two study groups. The intervention group (n = 26) followed a very low calorie diet with a supervised lifestyle intervention while the control group (n = 26) received routine lifestyle counseling. The changes in BMI, total nasal resistance, total nasal volume, and quality of life scores (Mini Rhinoconjunctivitis Quality of Life Questionnaire, MiniRQLQ) were assessed at baseline and after the intervention at 3 months.

RESULTS

The reduction in BMI in the intervention group was significantly greater than that achieved by patients in the control group (5.4 kg/m2 versus 0.5 kg/m2). Accordingly, AHI was reduced by 3.2 events/hour in the intervention group and by 1.3 in the control group. However, there were no significant changes in rhinometric measurements despite significant weight loss. There was no correlation between the reduction of BMI and the change in nasal resistance or MiniRQLQ scores.

CONCLUSION

Weight reduction does not seem to have any effect on nasal resistance or volume in overweight patients with mild OSA. Patients with OSA and impaired nasal breathing need specific medical or surgical treatment to restore nasal airflow.

Nasal Airway Volume and Resistance to Airflow

Background

In modern rhinological practice and research, rhinomanometry and acoustic rhinometry are widely used. The goal of this study was to determine whether there is correlation between rhinomanometrically derived nasal airflow resistances and acoustic rhinometrically derived nasal airway volumes.

Methods

To achieve the goal, a prospective cross-sectional study of a total of 316 patients complaining of nasal obstruction was performed. Resulting data were compared by means of Spearman rank correlations of the total number of patients and of subgroups.

Results

The total number of patients, and most subgroups, in both their untreated and decongested states showed significant negative correlation unilaterally between nasal airflow resistances and nasal volumes.

Conclusion

Rhinomanometric nasal airflow resistances and concurrent acoustic rhinometric nasal airway volumes are closely correlated. The combination of the two objective methods provides insight into nasal airflow physiology and nasal airway anatomy.

Changes in nasal cavity dimensions in children and adults by gender and age

OBJECTIVE

The aim of the study was to establish the dynamics of changes in the intranasal spaces of children and adults by gender and age.

MATERIALS AND METHODS

Each side of the nasal cavity was evaluated separately in 366 healthy subjects 9 to 74 years old. The following acoustic rhinometry parameters were analyzed: 1) I-C, distance between the isthmus nasi (I) and the head of the inferior turbinate (C); 2) CA-I, cross-sectional area at the isthmus nasi; 3) CA-C, at the head of the inferior turbinate; and 4) CA-F, the highest point on the rhinometric curve between points I and C.

RESULTS

Before age 11 years, the intranasal spaces were slightly larger in girls than in boys. After age 11 years the nasal parameters were larger in boys than in girls. The growth rates before age 17 years were as follows: I-C: 0.073 cm/yr, 0.135 cm/yr, CA-F: 0.055 cm2/yr, 0.133 cm2/yr (P < .00001), and CA-C: 0.010 cm2/yr, 0.034 cm2/yr (P < .02) in girls and boys, respectively. In subjects older than 16 years, the mean values of I-C were 1.707 cm, 1.934 cm (P < .0001), and of CA-C, 0.493 cm2, 0.611 cm2 (P < .0001) in women and men, respectively, and changed slightly over the year.

CONCLUSIONS

The parameters of intranasal spaces depend on age and gender. The dynamics of the changes is greater in boys than in girls and usually the growth is completed by the age of 16. After this age, nasal cavities are bigger in men than in women.

Nasal wall compliance in vasomotor rhinitis

Nasal compliance is a measure related to the blood volume in the nasal mucosa. The objective of this study was to better understand the vascular response in vasomotor rhinitis by measuring nasal cross-sectional area and nasal compliance before and after mucosal decongestion in 10 patients with vasomotor rhinitis compared with 10 healthy subjects. Nasal compliance was inferred by measuring nasal area by acoustic rhinometry at pressures ranging from atmospheric pressure to a negative pressure of -10 cmH2O. Mucosal decongestion was obtained with one puff per nostril of 0.05% oxymetazoline. At atmospheric pressure, nasal cross-sectional areas were similar in the vasomotor rhinitis group and the healthy subject group. Mucosal decongestion did not induce any decrease of nasal compliance in patients with vasomotor rhinitis in contrast with healthy subjects. Our results support the hypothesis, already proposed, of an autonomic dysfunction based on a paradoxical response of the nasal mucosa in vasomotor rhinitis. Moreover, the clearly different behavior between healthy subjects and vasomotor rhinitis subjects suggests that nasal compliance measurement may therefore represent a potential line of research to develop a diagnostic tool for vasomotor rhinitis, which remains a diagnosis of exclusion.