Nasal patency by rhinomanometry in patients with sensation of nasal obstruction

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Numerical comparison of inspiratory airflow patterns in human nasal cavities with distinct age differences

As a primary determinant of nasal physiological functions, the nasal morphology and its effects on the airflow dynamics have been extensively studied in literature. However, gross flow features reported in literature are mostly obtained from subjects at similar ages, while studies focusing on nasal subjects with distinct age differences are significantly less. To advance current understandings of nasal airflow dynamics in the context of age diversity, this study employed three anatomically accurate nasal cavity models with distinct age features (5-, 24- and 77-year-old models) and numerically compared the physiological nasal airflow fields within these nasal cavity models. To demonstrate the validity of the present numerical models, in vivo rhinomanometry measurement was conducted on the 24-year-old female nasal model, and key anatomical features and pressure-flow curves of all three models were compared with models with similar age features in literature work. Apart from results comparison based on conventional velocity flow fields and wall shear stress distributions, a method for quantifying flow partitions in confined airway spaces was developed to reveal the proportions of fractional flow that enters the olfactory region. Our results revealed dramatic intersubject discrepancies between considered nasal cavity models, especially for the fractional flow that enters the olfactory region. Specifically, the 5-year-old girl nasal model received the highest proportion of fractional flow, which accounts for 13.3% ~ 15% of overall inhalation flow rates under different activity levels. For the 24-year-old female model, on the contrary, the olfactory fractional flow was dramatically reduced (with a local to overall percentage around 4.3%-7.7%). Finally, for the elderly subject-77-year-old male model, minimum level of olfactory flux was observed with a local to overall percentage ranging between 3.1% and 4.9% for considered wide range of inhalation flow rates. Therefore, the local flow intersubject variation can reach nearly fourfold. The vast local flow difference is mainly due to the inherent anatomical features (e.g., immature nasal turbinate structure in the child model, the partial narrowing superior nasal valve in the elder model). The results may further lead to discrepant health effects associated with inhalation exposure to airborne particles.

The Functional Diversity of Nitric Oxide Synthase Isoforms in Human Nose and Paranasal Sinuses: Contrasting Pathophysiological Aspects in Nasal Allergy and Chronic Rhinosinusitis

The human paranasal sinuses are the major source of intrinsic nitric oxide (NO) production in the human airway. NO plays several roles in the maintenance of physiological homeostasis and the regulation of airway inflammation through the expression of three NO synthase (NOS) isoforms. Measuring NO levels can contribute to the diagnosis and assessment of allergic rhinitis (AR) and chronic rhinosinusitis (CRS). In symptomatic AR patients, pro-inflammatory cytokines upregulate the expression of inducible NOS (iNOS) in the inferior turbinate. Excessive amounts of NO cause oxidative damage to cellular components, leading to the deposition of cytotoxic substances. CRS phenotype and endotype classifications have provided insights into modern treatment strategies. Analyses of the production of sinus NO and its metabolites revealed pathobiological diversity that can be exploited for useful biomarkers. Measuring nasal NO based on different NOS activities is a potent tool for specific interventions targeting molecular pathways underlying CRS endotype-specific inflammation. We provide a comprehensive review of the functional diversity of NOS isoforms in the human sinonasal system in relation to these two major nasal disorders' pathologies. The regulatory mechanisms of NOS expression associated with the substrate bioavailability indicate the involvement of both type 1 and type 2 immune responses.

Cartilage Trap-Door Flap Technique for Correction of High Nasal Septum Deflection

OBJECTIVE

To introduce a novel cartilage trap-door flap technique in endonasal septoplasty to correct high dorsal deviation of the cartilaginous septum, and confirm its effectiveness.

DESIGN

Prospective observational study.

SETTING

Medical center.

METHODS

46 patients who had underwent septoplasty using the cartilage island flap technique to correct the high dorsal deviation from November 2014 to November 2015. The subjective symptoms were measured using the Nasal Obstruction Symptom Evaluation scale. The objective evaluations of the surgical results were analyzed using acoustic rhinometry. Post-operative status of the nasal septum was estimated by nasal endoscopic examination.

RESULTS

Among 46 patients, 32 cases (69.57%) were "complete correction", 14cases (30.43%) were "improved" with residual deviation and there was not "no-change" or "even worse" case based on endoscopic examination. Minimal cross-sectional area in convex side of nasal cavity was significantly changed from 0.22cm to 0.56cm after the surgery, and nasal volume in narrower side of nasal cavity was significantly changed from 2.44mL to 6.22 mL. The patients' nasal obstruction symptoms significantly reduced from 10.43 before the surgery to 1.45 after the surgery. During the follow-up period, the authors have not experienced any obvious complications such as saddle nose, septal perforation, and bleeding.

CONCLUSION

The proposed cartilage trap-door flap technique provides easy and effective results for dorsal deviations of the cartilaginous septum in selected cases without significant complications.

Impact of Varying Types of Nasal Septal Deviation on Nasal Airflow Pattern and Warming Function: A Computational Fluid Dynamics Analysis

Nasal septal deviations (NSD) have been categorized into 7 types. The effect of these different deviations on airflow pattern and warming function has not been fully investigated. The purpose of this study was to utilize a computational fluid dynamics approach to assess the impact of NSD of varying types on nasal airflow and warming function. Patients with each type of NSD were enrolled in the study, and a normal participant as the control. Using a computational fluid dynamics approach, modeling of nasal function was performed. Indices of nasal function including airflow redistribution, total nasal resistance, airflow velocity, and airflow temperature were determined. Among all types of NSD, the maximal velocity and total nasal resistance were markedly higher in type 4 and 7 deviations. The flow partition and velocity distribution were also altered in type 4 and 7 as well as type 2 and 6 deviations. Airflow in all categories of NSD was fully warmed to a similar degree. From a computational aerodynamics perspective, the type of septal deviation may contribute to altered airflow characteristics. However, warming function was similar between septal deviation types. Future studies will help to ascertain the functional importance of septal deviation types and the applicability of these computational studies.

Imaging of adult nasal obstruction

The commonest causes of nasal obstruction are rhinitis and chronic rhinosinusitis, which affect up to 30% and 14% of the adult population, respectively. The global financial burden is huge, estimated at $5 billion for rhinitis and $8.6 billion for chronic rhinosinusitis per annum in the USA. On referral for imaging, computed tomography (CT) is indicated initially when there is a suboptimal response to medical treatment of these mucosal diseases or there are "red flags," such as persistent unilateral obstruction, epistaxis, pain, and orbital or neurological symptoms. A mass visible at rhinoscopy or endoscopy in the nose or nasopharynx and lymphadenopathy are further indications. The anterior (cartilaginous) nose plays a key role in the aetiology of nasal obstruction as it accounts for 50-75% of the total resistance to airflow in the upper airway. It has been ignored in the imaging literature, but extensively evaluated by clinicians using a range of methods, including CT. Oblique reconstructions perpendicular to the parabolic curve of lamellar airflow provide accurate assessment of the anterior nose. A thorough and systematic approach to assessing the nose addresses the discrepancy between imaging and clinical evaluation of structural causes of nasal obstruction, especially septal deviation, reported in the surgical literature. Nasal tumours are a very uncommon cause of nasal obstruction; magnetic resonance imaging is commonly performed to assess their full extent and improve the specificity of diagnosis.

Septoplasty: is it possible to identify potential "predictors" of surgical success?

Septoplasty is one of the most frequent surgical procedures performed by otolaryngologists. Despite successful surgical correction, many patients are not satisfied with their outcomes. So far, in clinical practice there is no consensus of opinion about the reliability of objective measurements of nasal patency and the correlation between objective measurements and subjective nasal patency symptoms. This study aims to assess the reasons for patient dissatisfaction after septoplasty and optimise pre-operative diagnostic management to predict surgical outcomes. We analysed 494 patients undergoing septoplasties with turbinoplasty by subjective Nasal Obstruction Symptom Evaluation questionnaire (NOSE) and objective active anterior rhinomanometric measurements before surgery and after 6 months. In our series, 17% had postoperative septal re-displacement; all patients had an anterior deviations at baseline. We found that the type of septal deviation, anterior vs posterior, was a significant predictor of postoperative functional improvement, whereas demographic characteristics as age, gender and smoke habit were not. Our data suggest that the anterior segment of the nasal septum was the most critical area for nasal airway resistance and more difficult to manage because it is likely to re-displace vs the posterior one and for this reason it represents a negative predictor of postoperative satisfaction.

Nasal airflow resistance measured by rhinomanometry in a healthy population of China

BACKGROUND

Although nasal congestion is among the most common symptoms in subjects suffering from nasal diseases, relatively few data on normal airflow resistance are available for reference, especially in healthy Chinese subjects. The aim of present study was therefore to objectively measure the normal airflow resistance by rhinomanometry, and calculate mean and standard reference intervals in a cohort of healthy Chinese subjects.

METHODS

A total of 1084 participants were recruited in Huairou region in Beijing, China from November to December 2011. All participants were required to complete 2 questionnaires and undergo nasal examination and objective assessment of nasal resistance by rhinomanometry and acoustic rhinometry.

RESULTS

A total of 704 adults completed both questionnaires and nasal examinations; with 505 (71.73%) subjects considered "healthy" based on negative medical history, absence of nasal symptoms, and normal findings by nasal examination. The mean total nasal resistance in the congested nose was 0.168 Pa/cm³ /sec (95% CI, 0.068 to 0.268 Pa/cm³ /sec) at 75 Pa pressure and 0.243 Pa/cm³ /sec (95% CI, 0.112 to 0.374 Pa/cm³ /sec) at 150 Pa pressure. The mean total nasal resistance in males was significantly lower compared to females at 75 Pa and 150 Pa (p < 0.001). The mean unilateral nasal resistance was 0.357 Pa/cm³ /sec (95% CI, 0.034 to 0.680 Pa/cm³ /sec) at 75 Pa and 0.511 Pa/cm³ /sec (95% CI, 0.086 to 0.936 Pa/cm³ /sec) at 150 Pa, with no significant difference between males and females. Application of a vasoconstrictor decreased both total and unilateral nasal resistance, which was significant at 75 Pa.

CONCLUSION

These reference values maybe useful for the Chinese clinicians in evaluating the nasal function and in choosing and assessing efficacy of therapy for nasal congestion in Chinese patients.

The role of nasal fractional exhaled nitric oxide as an objective parameter independent of nasal airflow resistance in the diagnosis of allergic rhinitis

OBJECTIVE

Patients with allergic rhinitis (AR) show augmented activity of nitric oxide (NO) metabolism, similar to those in bronchial asthma (BA). We hypothesized that measurements of nasal fractional exhaled NO (FeNO) could be used as an objective marker to detect the presence of AR. Our objective was to clarify the influence of nasal airflow resistance (NAR) on nasal FeNO levels through an exhalation maneuver in symptomatic AR patients. We also examined the diagnostic test validity of the mean nasal FeNO level for disease discrimination by means of a receiver operating characteristic (ROC) curve analysis.

METHODS

Fifty-nine untreated perennial AR patients without BA and 60 healthy controls were enrolled in this retrospective cross-sectional study. The subjective symptoms were recorded and the disease severity was classified according to the Japanese guideline for AR. The oral and nasal FeNO measurements were carried out using a handheld electrochemical analyzer according to the ATS/ERS guidelines. NAR was measured using a rhinomanometer by the anterior method.

RESULTS

The patients in the moderate-to-most severe AR group showed significantly higher levels of oral FeNO compared to the controls. The AR patients in both the mild (n=25) and the moderate-to-most severe (n=34) groups showed significantly higher levels of nasal FeNO compared to the controls (44.1ppb, 54.5ppb, and 26.5ppb, respectively). There was no significant difference in total NAR between the AR patients and the controls. The results of our comparison of nasal FeNO and NAR values of the ipsilateral nasal cavity for each individual indicated no significant correlation between the two-paired parameters. The optimal cut-off point of the mean nasal FeNO level was calculated as 38.5ppb (with 71% sensitivity and 86% specificity) to discriminate the presence of AR.

CONCLUSION

Nasal FeNO measurements can be an objective parameter for the diagnosis and classification of perennial AR in Japanese individuals. Nasal FeNO and NAR appear to be two independent measures that can be used to objectively evaluate nasal functions.

Computed nasal resistance compared with patient-reported symptoms in surgically treated nasal airway passages: a preliminary report

BACKGROUND

Nasal airway obstruction (NAO) is a common health condition impacting mood, energy, recreation, sleep, and overall quality of life. Nasal surgery often addresses NAO but the results are sometimes unsatisfactory. Evaluating surgical treatment efficacy could be improved if objective tests were available that correlated with patient-reported measures of symptoms. The goal of this study was to develop methods for comparing nasal resistance computed by computational fluid dynamics (CFD) models with patient-reported symptoms of NAO using early data from a 4-year prospective study.

METHODS

Computed tomography (CT) scans and patient-reported scores from the Nasal Obstruction Symptom Evaluation (NOSE) scale and a visual analog scale (VAS) measuring unilateral airflow sensation were obtained pre- and postoperatively in two NAO patients showing no significant mucosal asymmetry who were successfully treated with functional nasal surgery, including septoplasty. Pre- and postsurgery CFD models were created from the CT scans. Numerical simulation of steady-state inspiratory airflow was used to calculate bilateral and unilateral CFD-derived nasal resistance (CFD-NR).

RESULTS

In both subjects, NOSE and VAS scores improved after surgery, bilateral CFD-NR decreased, and unilateral CFD-NR decreased on the affected side. In addition, NOSE and VAS scores tracked with unilateral CFD-NR on the affected side.

CONCLUSION

These preliminary results suggest a possible correlation between unilateral NR and patient-reported symptoms and imply that analysis of unilateral obstruction should focus on the affected side. A formal investigation of unilateral CFD-NR and patient-reported symptoms in a series of NAO patients is needed to determine if these variables are correlated.

A Prospective Population-based Study of Total Nasal Resistance in Korean Subjects

Objectives

Rhinomanometry is a widely accepted method for objective assessment of nasal patency. However, few studies have reported the values of otherwise healthy population for nasal resistance in East Asians. The purpose of this study was to measure normal total nasal resistance (TNR) values in a large sample of Korean adults and to reveal parameters contributing to TNR values.

Methods

Subjects were enrolled from a cohort of the Korean Genome and Epidemiology Study. They were evaluated by anthropometry, questionnaire, and active anterior rhinomanometry at transnasal pressures of 100 and 150 Pascal (Pa).

Results

The study sample consisted of 2,538 healthy subjects (1,298 women and 1,240 men) aged 20 to 80 years. Normal reference TNR values were 0.19±0.08 Pa/cm³/second at 100 Pa and 0.22±0.09 Pa/cm³/second at 150 Pa. The TNR of women was significantly higher than that of men (P<0.0001). TNR decreased with increasing age in both genders (P<0.05). In women, lower body weight was related to increasing TNR. In men, current smokers had higher TNR than ex-smokers and never smokers.

Conclusion

The results of the present study provide information regarding the values of otherwise healthy population of TNR and parameters associated with TNR in Korean adults.

Use of rhinomanometry in common rhinologic disorders

Rhinomanometry is a functional test of nasal aerodynamics that measures transnasal airflow and the pressure gradient allowing nasal resistance to be calculated from these data. Three methods of rhinomanometry that are currently in use are anterior rhinomanometry, posterior (peroral) rhinomanometry and postnasal (pernasal) rhinomanometry. The usefulness of this method has increased owing to the development of technology and use of microcomputers connected to the measuring devices. Rhinomanometry can be used for: clinical evaluation of the symptom of nasal obstruction; research in nasal physiology; allergy challenge testing; pre- and post-treatment assessments of surgical or medical therapy; and evaluation of patients with sleep apnea.

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.