Rhinomanometric reference intervals for normal total nasal airflow resistance.

BACKGROUND: Reference intervals (RIs) or mean values for normal total nasal airflow resistance are essential for the diagnosis of nasal obstruction. Data relating to nasal airflow are not standardised, and valid and reliable RIs do not exist for the time being. This meta-analysis aimed to determine such "standard" 95%-RIs. METHODOLOGY: Research of related literature listed in Medline, Embase, Cochrane, and Web of Science databases. RESULTS: Airflow resistance data were gathered from 38 studies using active anterior rhinomanometry at a differential pressure of 150Pa to examine patients under congested and decongested mucosal conditions. In the meta-analysis overall values and RIs for normal total nasal airflow resistance under congested nasal mucosal conditions were calculated for all subjects at 0.25Pa/cm3/s (95%-RI 0.10-0.40Pa/cm3/s), adults regardless of gender at 0.25Pa/cm3/s (95%-RI 0.12-0.38Pa/cm3/s), men at 0.24Pa/cm3/s (95%-RI 0.09-0.39Pa/cm3/s), and women at 0.26Pa/cm3/s (95%-RI 0.08-0.44Pa/cm3/s). Asian, African and Caucasian ethnic groups exhibited rising airflow resistance mean values: 0.23Pa/cm3/s (95%-RI 0.08-0.39Pa/cm3/s), 0.25Pa/cm3/s (95%-RI 0.11-0.38Pa/cm3/s) and 0.26Pa/cm3/s (95%-RI 0.13-0.38Pa/cm3/s), respectively. Lower overall mean values resulted under decongested nasal mucosal conditions. CONCLUSION: The reference intervals and mean values ascertained in this meta-analysis improve the diagnosis of nasal obstruction and may represent a useful supplement in existing guidelines for the standardisation of rhinomanometric measurements.

Inferior turbinate reduction; coblation versus microdebrider - a prospective, randomised study.

OBJECTIVES: We prospectively evaluated and compared the safety, subjective and objective efficacy of the coblation and microde- brider for inferior turbinate reduction. METHODS: We designed a prospective randomized trial recruiting 70 patients with symptomatic enlarged inferior turbinates. Forty had coblation and 30 had microdebrider. Objectively, we scored each inferior turbinate size from 1 to 3 pre- and post-operatively. Subjectively, patients completed a visual analogue scale (VAS) evaluating their nasal symptoms, before and after surgery. RESULTS: Both techniques resulted in subjective significant improvement in the VAS for nasal obstruction, and other nasal symptoms. Comparing both groups, coblation showed significantly less pain than the microdebrider. Postoperative bleeding and mucosal tears were less frequent with coblation than with microdebrider but this was nonsignificant. Patient satisfaction significantly improved after both techniques. CONCLUSION: The submucous coblation is as effective as microdebrider for inferior turbinate reduction. It is easily performed with significantly less postoperative pain than the microdebrider. Both techniques produce significant reduction of the size of the turbinates and associated with a satisfactory improvement of the nasal obstruction, nasal secretion, crust formation, itching, sneezing and dryness. The side effects are minimal with both procedures with significant patient satisfaction postoperatively.

Normal nasal patency: problems in obtaining standard reference values for the surgeon.

This review examines why there is no normal range of nasal patency available to the surgeon when assessing nasal obstruction, and discusses the factors that influence nasal patency. Current normal ranges are examined and criticised because of the variability of normal values and the poor sampling methods used. Instability of physiological nasal patency is related to factors such as the nasal cycle and the nose's direct exposure to the external environment. Decongestion of the nose is proposed as a way of stabilising anatomical nasal patency, and measurements of patency in this state may be more useful to the surgeon. Population studies are needed to establish a normal range, but these studies must control for factors such as age, height, sex, and nasal shape and size related to climatic adaptation. Rather than classify populations according to unscientific categories such as race, anthropometric measures such as the nasal index are proposed.

Airway assessment by four-phase rhinomanometry in septal surgery.

PURPOSE OF REVIEW: This article updates the state of the art in functional ventilation tests of the nasal airway. Multidisciplinary international cooperation has led within the last years to the development of four-phase rhinomanometry (4PR) by eradicating the errors of the 'classic' rhinomanometry. RECENT FINDINGS: Physical experiments, mathematical models and comprehensive statistical analyses implicate that the nasal breath consists of four phases of different diagnostic importance. Presuming the motility of the nasal entrance, it is necessary to depict the elastic behavior within the rhinomanometric curve, as well as to use new parameters for the clinical evaluation of the nasal obstruction. The parameters logarithmic vertex resistance and logarithmic effective resistance are related to the sensing of the patient. Their clinical importance was proved in studies of more than 12 000 patients. SUMMARY: The human eye is not able to estimate the degree of impairment in nasal breathing. Therefore, a functional diagnosis is mandatory to avoid unnecessary surgery and to control the results. 4PR is a substantial improvement over the currently used methods. It should be implemented in the standards of the international standardization committee for the objective assessment of the upper airway (ISOANA). Practical hints for correct measurements are given.

A guide to practical aspects of measurement of human nasal airflow by rhinomanometry.

The guide is intended for all those interested in measuring human nasal airflow by rhinomanometry, either for clinical or research purposes. The guide is written in non-technical language so that it may be understood by nursing and support staff who may need to make measurements using rhinomanometry. It is not a systematic review of the literature but a personal view based on over 40 years experience of measuring nasal airflow. The guide introduces the basic principles of nasal airflow and pressure and their measurement. The following topics are discussed: anterior and posterior rhinomanometry and their relative problems and benefits, control of errors in measurement, standard operating procedures, calibration of equipment, measurement of the totally obstructed nose, reproducibility and sensitivity of rhinomanometry, hygiene, factors influencing nasal airflow such as rest and exercise, alcohol, medicines, temperature and humidity and diseases such as common cold and allergy.

Can we always trust rhinomanometry?

OBJECTIVES: Rhinomanometry before and after decongestion distinguishes a nasal airway organic stenosis from congestion of nasal mucosa in patients with nasal stuffiness. Together with rhinoscopy and patient history, it is used to decide if nasal surgery would benefit the patient. Rhinomanometry measurements should thus be reliable and reproducible. MATERIALS AND METHODS: We performed repetitive active anterior rhinomanometry in 9 persons during 5 months to test reproducibility of nasal airway resistance (NAR) over time. We also did test-retest measurements in several participants. Xylometazoline hydrochloride was applied in each nasal cavity to minimize effects of mucosal variation and the nasal cavity was examined with rhinoscopy. The participants evaluated subjective nasal stuffiness on a visual analogue scale (VAS). RESULTS: The long term mean coefficient of variation (CV) of NAR over time was 27% for the whole group while the short term CV was 7 - 17% for test-retest within an hour. Mean NAR reduction after decongestion was 33%, but 13% of NAR values were not reduced after decongestion. Participants had difficulties estimating stuffiness on a VAS in 15% of the assessments, but there was no correlation between the VAS estimates and NAR. CONCLUSION: We found a high NAR variation over a period of five months. This implies low long-term rhinomanometry reproducibility and we suggest future research on standardised decongestion to increase the reproducibility.

Functional anatomy of the nose.

The human nose is a very complex entity with a great amount of variation among and within different human populations. Even though the morphology of the nasal pyramid and its soft tissue coverage is principally known, a standardized nomenclature does not yet exist. The past two decades have witnessed a considerable increase of new studies on the functional morphology of the external nasal anatomy. Detailed anatomic and clinical knowledge about the external nose is a prerequisite for successful rhinosurgery, thus this report deals with the basic structures necessary for functional and aesthetic rhinoplasty.

North African reference equation for peak nasal inspiratory flow.

AIM: To assess, in healthy North African subjects, the applicability and reliability of a previously published reference equation and normal values for peak nasal inspiratory flow, and to calculate a peak nasal inspiratory flow reference equation in this population. SUBJECTS AND METHODS: Anthropometric data were recorded in 212 volunteers (100 females and 112 males) aged 13-27 years. Peak nasal inspiratory flow was measured several times. Univariate and multiple linear regression analyses were used to determine the reference equation. RESULTS: The previously published reference equation and normal values did not reliably predict peak nasal inspiratory flow in the study population. In our subjects, the reference equation (r2 = 30 per cent) for peak nasal inspiratory flow (l/min) was 1.4256 × height (m) + 33.0215 × gender (where 0 = female, 1 = male) + 1.4117 × age (years) - 136.6778. The lower limit of normal was calculated by subtracting from the peak nasal inspiratory flow reference value (84 l/min). CONCLUSION: This is the first published study to calculate a reference equation for peak nasal inspiratory flow in North African subjects. This equation enables objective evaluation of nasal airway patency in patients of North African origin.

Active anterior rhinomanometry in paediatrics. Normality criteria.

BACKGROUND: Active anterior rhinomanometry with a face mask was used to establish the lower age limit for application of the technique, define normality reference standards, and determine the most appropriate pressure for referencing the nasal resistance values. MATERIAL AND METHODS: A total of 409 children of both sexes and aged 5-14 years were studied. The subjects were selected from among healthy children in two primary care centres and one school. The Rhinospir 164 rhinomanometer was used for the tests. Rhinomanometry was performed according to the guidelines of the International Committee on Standardization of Rhinomanometry. The SPSS (Statistical Package for the Social Sciences) was used for the analysis of the results. RESULTS: The study sample was divided into five age groups involving intervals of two years from 5 to 14 years of age, and four body surface groups. The dependent variables studied (resistances and flows at pressure differences of 75 and 100) showed significantly different mean values according to age and body surface. All the mean ratios were over 1.4 units, i.e., the measures of each variable on one side and the other differed between 40% and 44%. CONCLUSIONS: 1.- The lower age limit for rhinomanometry is five years. 2.- The most appropriate pressures for referencing the resistance and flow values are 75 and 100. 3.- The reference standards are established with respect to total resistance and according to subject age and body surface.

[Objective evaluation of nasal ventilation function in healthy adults in Tianjin area].

OBJECTIVE: To establish reference values of acoustic rhinometry, rhinomanometry and rhinospirometer in healthy adults in Tianjin area, analyze the effects of age,sex and side on the value, investigate the correlation of the measure values, offer the diagnosis date for test nasal ventilation function in Tianjin area. METHOD: Four hundred and sixty-six healthy adults in Tianjin area were tested. A1 acoustic rhinometry was used to measure the minimum cross-sectional area (MCA), distance of the minimal cross-sectional area to the nostril (DCAN) and the nasal volume from 0-5 cm, 2-5 cm (V5, V2-5); At 150 Pa, 75 Pa and broms, NR6 Rhinomanometry was used to measure unilateral nasal inspiratory resistance (IR)and expiratory resistance (ER), bilateral nasal inspiratory and expiratory resistance (TIR and TER), and differences of the bilateral nasal resistance can be calculated; NV1 Rhinospirometer was used to measure unilateral inspiratory capacity (IC) and expiration capacity (EC), and the nasal partitioning ratio (NPR) can be calculated. Practical measure the distance of nostril to ahead of the inferior turbinate and compare with DCAN. Make the correlational analysis on different index of three exam. RESULT: Reference values of acoustic rhinometry: MCA was (0.45 +/- 0. 16) cm2 for male, (0.44 +/- 0.16) cm2 for female; V2-5 was (3.52 +/- 1.38) cm3 for male, (3.36 +/- 1.22) cm3 for female, V5 was (5.10 +/- 1.47) cm3 for male, (4.86 +/- 1.12) cm3 for female; DCAN have two distance, (2.22 +/- 0.398, 0.53 +/- 0.625) cm was for male, (2.10 +/- 0.37, 0.67 +/- 0.15) cm was for female. No significant gender, side and age differences were shown in MCA, V5, V2-5. Significant gender differences were shown in DCAN but no side and age differences. Reference values of rhinomanometry: Significant gender but no side and age differences were shown in IR, ER, TIR, TER. Reference values of rhinospirometer: IC was (2.06 +/- 1.10) L/20 s for male, (1.37 +/- 0.34) L/20 s for female, EC was (2.15 +/- 1.23) L/20 s for male (1.39 +/- 0.58) L/20 s for female. NPRi was 0.11 [0.05, 0.23],NPRe was 0.11 [0.05, 0.19]. Significant gender but no side and age differences were shown in IC and EC. No gender and age differences were shown in NPRi and NPRe. There was significant correlation found between MCA and IR/ER/IC/EC, IR and IC, ER and EC, Rlr and NPRi/ NPRe. CONCLUSION: Acoustic rhinometry,rhinomanometry and rhinospirometer can be useful reference values to evaluate nasal ventilation function, more value will be found if use the three together.

The use of objective measures in selecting patients for septal surgery.

To improve results in septal surgery patient selection is the mainstay of a successful outcome. Patient history is the basis as well as clinical examination but both are subjective and must be considered towards a background with a high frequency of septal deviation in the population and a lack of good correlation between function and status. Rhinomanometry and acoustic rhinometry as well as nasal peak inspiratory flow are tests of different nasal parameters as resistance to breathing, nasal dimensions and flow. This article illuminates the use of these more objective tests in selection of patients for septo plasty. Objective tests have in several studies shown to predict postoperative satisfaction while normal values can be a marker for a poor surgical outcome. Pros and cons with objective tests are discussed and the conclusion is: operate when there is a good correlation between the patientA`s status, history and the results of rhinometry!

Consensus report on acoustic rhinometry and rhinomanometry.

With respect to acoustic rhinometry, new elements concern the problems related to the interpretation of the minimal cross-sectional area, and the presentation of a protocol for a multinational study, which aims to define a normal nose. Also, the previously issued recommendations for standardisation for technical specifications and standard operating procedures are briefly reviewed. For rhinomanometry, new insights into the field of fluid dynamics are highlighted, as well as their repercussion on more recent graphical representations for active anterior rhinomanometry such as four phases rhinomanometry and resistometry. For acoustic rhinometry as well as rhinomanometry, a more stringent standardisation of decongestive procedures is suggested.

Nasal congestion and airway obstruction: the validity of available objective and subjective measures.

Rhinomanometry and acoustic rhinometry provide the best methods for objective assessment of nasal obstruction. Advanced equipment for these methods is now available, and most devices are reliable provided that care is taken to calibrate the device properly and, for rhinomanometers, the user is completely familiar with the mathematical algorithm for resistance used by the accompanying software. Suggestions for improvement in standardization of rhinomanometry are given. Rhinomanometry and rhinometry are both capable of objectively measuring nasal obstruction, but they are complementary methods that assess different nasal attributes, the former being a test of nasal function, and the latter a representation of nasal geometry. Objective methods are strongly recommended for use in the evaluation of pharmacologic agents that are expected to improve nasal airflow. When further studies needed to validate their use for long-term comparisons are done, these methods should find an increasing place in clinical practice.

Nasal function in self-reported chemically intolerant individuals.

Nasal function has not yet been investigated under controlled exposures in individuals with self-reported Multiple Chemical Sensitivity (sMCS). Therefore, anterior rhinomanometry and acoustic rhinometry were applied in 12 individuals with sMCS, and 12 age-matched controls. The sMCS individuals and controls were selected on the basis of a standardized questionnaire. Controlled 4-hr exposures to ethylbenzene and 2-butanone were performed during 4 sessions. Exposures were close to the current German threshold limit values, and they approximated odor thresholds. Subjects with sMCS had a significant decrease in the flow value in anterior rhinomanometry, independent of substance and doses, compared with controls. This result suggests somatic reactions to the exposure. The result must be confirmed in additional studies, and pathophysiological examinations must be performed. For these investigations, anterior rhinomanometry was usable, but acoustic rhinometry can be recommended only after sufficient standardization has occurred. Furthermore, biochemical parameters of nasal mucosa must be considered.

Accuracy of nasal cannula pressure recordings for assessment of ventilation during sleep.

Nasal prong pressure monitoring (PNOSE) is utilized to assess ventilation during sleep. However, it has not been rigorously validated against the gold standard of face-mask pneumotachography (VFM). Therefore, we compared PNOSE with VFM in 20 patients with suspected sleep apnea during nocturnal polysomnography, and analyzed factors affecting accuracy of PNOSE-derived variables. Patients rated their nasal obstruction on a visual analog scale. Mean +/- SE apnea/hypopnea index (AHI) by VFM was 24.0 +/- 5.1 h(-1). The bias (mean difference) and limits of agreement (+/- 2 SD) of AHI derived from PNOSE, and square root-transformed PNOSE, a measure proposed as a surrogate of airflow, were +3.9 (+/- 4.6), and -0.9 (+/- 9.0) h(-1). Subjective scores of nasal obstruction before polysomnographies did not herald inaccuracy of AHI from PNOSE. Square root-transformed PNOSE closely tracked pneumotachographic airflow over 10 breaths (r(2) among signals 0.88 to 0.96) but the relationship among these signals was highly variable if comparisons were extended over an entire night. Compared with face-mask pneumotachography, nasal pressure monitoring provides accurate AHI for clinical purposes even in patients perceiving nasal obstruction. Square-root transformation provides near linear nasal pressure/airflow relationships over a short time but is not essential for estimation of AHI.