Acoustic rhinometry in preschool children

Endonasal measurements by acoustic rhinometry in children: A preliminary study

The acoustic reflection method (ARM) is a non-invasive technique which uses the reflection of acoustic waves to measure the cross sectional area of nasal cavities in adults and patency of endotracheal tubes. Characteristics and volume of normal nasal cavities in pre-school children has so far not been studied.

OBJECTIVE

The aim of this study was to determine the optimal ARM recording and the minimal cross-sectional area (MCA) and volume (NV) values in healthy children.

DESIGN

Prospective monocentric study using the ARM in pre-school children (<6 years of age).

RESULTS - DISCUSSION

Seventy children (age 2 to 5) were included in the study. Reliable measures were difficult to obtain in children younger than 2 years of age. The use of a standard nosepiece and a single-use surgical filter enabled reliable, serial recordings. Mean MCA values were 0.46, 0.53 and 0.58 cm² in the 24-35, 36-47 and 48-60 months-old age groups, respectively. Mean NV values were 2.14, 2.59, and 2.86 cm³ in the same age groups. The MCA and NV values were significantly correlated with height, age and weight. In conclusion, the ARM is feasible in children over the age of 2 and seems to be a promising non-invasive tool to study the nasal cavity patency, anatomy, and volume.

Specific Nasal Provocation Test with Dermatophagoides Pteronyssinus, Monitored by Acoustic Rhinometry, in Children with Rhinitis

Background

Currently, the diagnosis of allergic rhinitis (AR) is arrived at predominantly by a clinical history and by systemic sensitization tests, but specific nasal provocation tests (NPT) may establish a better direct correlation between etiologic surveyed allergens and nasal symptoms.

Objectives

To standardize the specific NPT with one of the most important house-dust mites, Dermatophagoides pteronyssinus, monitored by acoustic rhinometry, in children and adolescents, and propose a simplified specific NPT to improve its clinical applicability as a diagnostic tool.

Methods

Sixteen controls (group 1) and 17 patients with an AR diagnosis sensitized to D. pteronyssinus (group 2) underwent a specific NPT with D. pteronyssinus. The acoustic rhinometry was performed after instillation of 0.15 mL of increasing concentrations of D. pteronyssinus (5000 BU/mL). The test was finalized after (1) instillation of the final concentration of D. pteronyssinus, or (2) after a 20% or more reduction in the volume of the first 5 cm of the nasal cavity (V5), or (3) a score of >3 in the symptoms questionnaire (a score from 0 to 7). A simplified specific NPT with two concentrations was proposed and implemented in a group of 10 patients with AR (group 3).

Results

At the end of the specific NPT, the median (range) variation in V5 was -5.7% (-9 to 4%) in the control group and -22.8% (-24 to -20%) in group 2. None of the patients in the control group and 88% of group 2 (15/17) showed positive specific NPT results. The simplified specific NPT triggered a positive response in 80% of patients in group 3, with median (range) V5 variation of -30.4% (-36 to -20%).

Conclusion

This protocol has been proven safe and useful to differentiate between children and adolescents with AR and controls. Concentrations of 1:1000 and 1:100 D. pteronyssinus were the best for use in simplified specific NPT, which made it simpler and faster, and expanded its clinical applicability.

Mudança nas áreas nasais em crianças com respiração oral após a limpeza e massagem nasal

RESUMO A avaliação e quantificação das possíveis alterações da cavidade nasal são necessárias para o auxílio diagnóstico e tratamento de crianças que respiram predominantemente pela boca. O modo respiratório oral pode desencadear distúrbios da fala, deformidades da face, mau posicionamento dos dentes, postura corporal inadequada e alterações no sistema respiratório. Objetivo analisar as mudanças ocorridas na geometria das cavidades nasais, antes e depois da limpeza nasal por meio da aeração nasal e da rinometria acústica em crianças com respiração oral. Método Foram selecionadas 20 crianças com idade entre quatro e 12 anos. A coleta foi realizada no Laboratório Multifuncional do Departamento de Fonoaudiologia da Universidade Federal de Pernambuco. Foi aplicado o Índice de Identificação dos Sinais e Sintomas da Respiração Oral; marcação da aeração nasal por meio do espelho milimetrado de Altmann e o exame da geometria nasal por Rinometria Acústica. Depois da limpeza e massagem nasal com o soro fisiológico, foram realizados os mesmos procedimentos. Resultados Observaram-se mudanças significantes nas áreas relativas ao fluxo aéreo nasal em ambos os lados, após limpeza e massagem nasais. Quanto à geometria nasal, aferida por meio da rinometria acústica, o efeito da limpeza e massagem nasal mostrou-se discreto, quando feita a comparação entre as narinas. Conclusão As medidas de aeração nasal mostraram sensibilidade à técnica de limpeza e massagem e as medidas da geometria nasal confirmaram seu efeito sobre a fisiologia respiratória.

Upper airway resistance during growth: A longitudinal study of children from 8 to 17 years of age

OBJECTIVE

To study upper airway breathing in 115 children annually from 8 to 17 years of age with the hypothesis that upper airway respiratory needs increase steadily during growth and show sexual dimorphism.

MATERIAL AND METHODS

To calculate nasal resistance, airflow rate (mL/s) and oronasal pressures (cmH2O) were measured during rest breathing in a seated position using the pressure-flow technique.

RESULTS

Median values of oronasal pressure ranged at different ages in girls from 0.88 to 1.13 and in boys from 0.92 to 1.44 cmH2O, being 0.95 and 0.93 cmH2O at the age of 17 years, respectively. The gender differences were statistically significant in four age groups (P < .05 by the Mann-Whitney test). Mean values of nasal resistance decreased from 8 to 17 years of age in girls from 4.0 (±3.27) to 2.4 (±2.30) and in boys from 3.3 (±2.48) to 1.5 (±0.81) cmH2O/L/s. However, there was an increase in resistance in 11-year-old girls and 12-year-old boys and at the age of 15 in both genders (P < .05 by paired t-test).

CONCLUSIONS

Respiratory efforts stabilize oronasal pressure to maintain vital functions at optimal level. Nasal resistance decreased with age but increased temporarily at the prepubertal and pubertal phases, in accordance with other growth and possibly hormonal changes. When measuring upper airway function for clinical purposes, especially in patients with sleep apnea, asthma, allergies, cleft palate, or maxillary expansion, the measurements need to be compared with age- and gender-specific values obtained from healthy children.

Acoustic rhinometry in mouth breathing patients: a systematic review

INTRODUCTION

When there is a change in the physiological pattern of nasal breathing, mouth breathing may already be present. The diagnosis of mouth breathing is related to nasal patency. One way to access nasal patency is by acoustic rhinometry.

OBJECTIVE

To systematically review the effectiveness of acoustic rhinometry for the diagnosis of patients with mouth breathing.

METHODS

Electronic databases LILACS, MEDLINE via PubMed and Bireme, SciELO, Web of Science, Scopus, PsycInfo, CINAHL, and Science Direct, from August to December 2013, were consulted. 11,439 articles were found: 30 from LILACS, 54 from MEDLINE via Bireme, 5558 from MEDLINE via PubMed, 11 from SciELO, 2056 from Web of Science, 1734 from Scopus, 13 from PsycInfo, 1108 from CINAHL, and 875 from Science Direct. Of these, two articles were selected.

RESULTS

The heterogeneity in the use of equipment and materials for the assessment of respiratory mode in these studies reveals that there is not yet consensus in the assessment and diagnosis of patients with mouth breathing.

CONCLUSION

According to the articles, acoustic rhinometry has been used for almost twenty years, but controlled studies attesting to the efficacy of measuring the geometry of nasal cavities for complementary diagnosis of respiratory mode are warranted.

The acoustic reflection method for the assessment of paediatric upper airways

The acoustic reflection method (ARM) is based on the analysis of the reflection of an acoustic wave in the airway, allowing the calculation of its longitudinal cross-sectional area profile and airway resistance. The ARM represents a simple, quick and totally non invasive tool for the investigation of the upper airways, requiring minimal cooperation, which makes this technique particularly suitable for children. Normal values of the minimal cross sectional area of the upper airways in children have been recently published. The ARM has shown its utility in the investigation of the nasal cavity in healthy and diseased children and of the upper airways in children with various diseases such as mucopolysaccharidosis and cystic fibrosis. This simple, rapid, and inexpensive technique seems promising for the non-invasive investigation of the whole upper airway during wakefulness in children, both in health and disease, and may constitute a complementary or alternative method to explore and follow children with anomalies of the upper airways.

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.

Objective improvement in nasal congestion and nasal hyperreactivity with use of nasal steroids in persistent allergic rhinitis

OBJECTIVE

Our objective was to evaluate the action of topical nasal steroid in nasal congestion and nasal hyper-reactivity in children and adolescents with persistent allergic rhinitis.

METHODS

Twenty atopic children and adolescents (6 to 18 years) with moderate-to-severe persistent allergic rhinitis (PAR) were treated with mometasone furoate (100 microg once a day) for 21 days. At the beginning and end of treatment, the following were recorded: a) nasal symptoms score; b) several parameters of nasal congestion measured by acoustic rhinometry (SRE 2000 Rhinometrics); c) degree of nasal hyper-reactivity to histamine (concentration of histamine necessary to induce at least 100% increase in total nasal resistance during nasal provocation test). Data were compared with those from 20 controls.

RESULTS

Compared to controls, PAR patients had significantly higher score of symptoms, as well as higher degree of nasal hyper-reactivity and lower nasal volumes. After treatment, there was a significant decrease in the mean nasal symptoms score (8.0 versus 3.8; p < 0.001) and in the nasal hyper-reactivity (histamine concentration: 0.72 mg/ml versus 2.60 mg/ml; p < 0.001). Congestion improvement was observed by the increase in all acoustic rhinometry parameters. Among all studied volumes, the volume in the segment between 2 and 5 cm showed the highest mean increase (19.8%).

CONCLUSION

Treatment with topical nasal steroid objectively reduced nasal congestion and nasal histamine hyper-reactivity in children and adolescents with PAR.

Upper and lower airway patency are associated in young children

BACKGROUND

Although allergic rhinitis and asthma frequently coexist, the nature of this association is poorly understood. Therefore, we examined whether upper and lower airway patency are associated.

METHODS

We investigated 221 6-year-old children from the Copenhagen Prospective Study on Asthma in Childhood birth cohort, assessing upper airway patency by acoustic rhinometry before and after alpha-agonist, and lower airway patency by spirometry before and after beta2-agonist. Furthermore, we measured blood eosinophil count, nasal eosinophilia, total IgE, and fraction of exhaled nitric oxide. Associations were investigated by generalized linear models.

RESULTS

Decongested nasal airway patency and post-beta2 FEV(1) were significantly associated (P = .007). The association remained significant after adjustments for sex, body size, FVC, and atopic diseases (beta-coefficient 2.85 cm(3); 95% CI, 0.42 to 5.29; P = .02). Baseline values of upper and lower airway patency were also significantly associated (beta-coefficient 0.89 cm(3); 95% CI, 0.26-1.51; P = .01). In addition, blood eosinophil count and nasal eosinophilia were inversely associated with decongested nasal airway patency, beta-coefficient -0.42 cm(3) (95% CI, -0.77 to -0.07; P = .02) and beta-coefficient -0.47 cm(3) (95% CI, -0.89 to -0.05; P = .03), respectively.

CONCLUSIONS

We found a strong and consistent association between upper and lower airway patency. This may be due to a common pathology, as suggested by the inverse association between decongested nasal airway patency, blood eosinophil count, and nasal eosinophilia. Alternatively, the association between upper and lower airway patency might reflect a physiologic background for the common comorbidity.

Objective assessments of allergic and nonallergic rhinitis in young children

BACKGROUND

Allergic and nonallergic rhinitis are common childhood disorders.

OBJECTIVE

To study nasal eosinophilia and nasal airway patency in young children with allergic and nonallergic rhinitis to assess the pathology behind such diagnoses.

METHODS

We investigated 255 children at six years of age from the Copenhagen Prospective Study on Asthma in Childhood birth cohort assessing rhinitis history, specific immunoglobulin E relevant to rhinitis symptoms, nasal eosinophilia and nasal airway patency by acoustic rhinometry before and after decongestion. Associations were studied in a multivariate graphical model corrected for gender, height and nasal steroid usage.

RESULTS

Allergic rhinitis was significantly and directly associated with irreversible nasal airway obstruction (reduced decongested nasal airway patency) (P = 0.004), whereas nonallergic rhinitis was not. Both allergic rhinitis (P = 0.000) and nonallergic rhinitis (P = 0.014) were directly and significantly associated with nasal eosinophilia, but this association was stronger for allergic rhinitis.

CONCLUSION

Allergic rhinitis and nonallergic rhinitis are of different pathologies as suggested from their different associations not only to allergy but importantly also to irreversible nasal airway obstruction and eosinophilic inflammation. Allergic rhinitis was significantly associated with nasal eosinophilia and irreversible nasal airway obstruction suggesting chronic inflammation and structural remodeling of the nasal mucosa in children at the age of 6 years. Nonallergic rhinitis exhibited no change in the nasal airway patency, but some nasal mucosal eosinophilia albeit less than children with allergic rhinitis.

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.

Reference values for acoustic rhinometry in children from 4 to 13 years old

BACKGROUND

Despite a growing number of studies using acoustic rhinometry (AR) in children, no reference material exists that incorporates the entire age and height interval of preschool children up to puberty for a range of rhinometric variables. The aim of this study is to provide a reference range for nasal volumes and minimum cross-sectional areas (MCAs) in healthy nondecongested children aged 4-13 years old.

METHODS

Two hundred fifty-six primary school children (mean, 7.95 years; range, 3.8-13.1 years; 123 boys/133 girls) were measured by AR. Variables were MCA (first, second, and absolute minimum) and nasal volumes from 0 to 4 cm (Vol0-4), 0 to 5 cm (Vol0-5), 1 to 4 cm (Vol1-4), and 2 to 5 cm (Vol2-5) into the nasal cavity. Height and weight were measured and atopic status was determined by skin-prick test. Age and current and past respiratory health were recorded from a questionnaire.

RESULTS

In multiple linear regression models height was the main predictor for all AR variables although weight also was a significant predictor of MCAs. There was no association between any AR variables with sex, atopy, or hay fever but children with current wheeze (within last 12 months) and asthma had decreased nasal patency.

CONCLUSION

This article presents the most extensive current reference material for AR in nondecongested prepubescent healthy children. The presented reference material will facilitate the interpretation and evaluation of future and present epidemiologic studies based on AR in children.