Measurement Of Nasal Airway Resistance Research Articles

The effect of adenoidectomy on occlusal development and nasal cavity volume in children with recurrent middle ear infection

ObjectivesThe aim of the study was to examine the effect of adenoidectomy on occlusal/dentoalveolar development and nasal cavity volume in children who underwent tympanostomy tube insertion with or without adenoidectomy due to recurrent episodes of middle ear infection. MethodsThis prospective controlled study consisted of two randomly allocated treatment groups of children, younger than 2 years, who had underwent more than 3–5 events of middle ear infection during the last 6 months or 4–6 events during the last year. At the mean age of 17 months tympanostomy tube placement without adenoidectomy (Group I, n=63) tympanostomy tube placement with adenoidectomy (Group II, n=74) was performed. At the age of 5 years 41 children of the original Group I (14 females, 27 males, mean age 5.2 yrs, SD 0.17) and 59 children of the original Group II (17 females, 42 males, mean age 5.2 yrs, SD 0.18) participated in the re-examination, which included clinical orthodontic examination defining morphological and functional craniofacial status and occlusal bite index to measure upper dental arch dimensions. Acoustic rhinometry and anterior rhinomanometry was made by otorhinolaryngologist at the same day. ResultsNo statistically significant differences were found between the groups in the frequencies of morphological or functional characteristics or upper dental arch measurements or in the minimal cross-sectional areas or inspiratory nasal airway resistance measurements. ConclusionCombining adenoidectomy with tympanostomy tube insertion in the treatment of recurrent middle ear infection at an early age (under the age of 2 years) does not seem to make any difference in occlusal development in primary dentition at the age of 5 years as compared to tympanostomy tube insertion only. Since adenoid size was not evaluated, the findings do not allow interpretation that hypertrophic adenoids should not be removed in children with continuous mouth breathing or sleep disordered breathing.

Experimental System for the Analysis of Nasal Procedures: Initial Experience with Inferior Turbinate Reduction

Objectives: 1) Develop simple cadaveric flow/pressure analysis system for experimental use for nasal procedure simulation. 2) Assess changes in nasal airway resistance in simulated inferior turbinate (IT) hypertrophy, normal state, and reduced, out-fractured conditions. Methods: An open thermodynamic nasal cavity experimental cadaveric model was created using an Omega HHP-103 digital manometer and oxygen flow regulator. For pressure testing, one pressure measurement catheter was placed at the internal nasal valve, isolating the nasal cavity from external nasal valve resistance. The second pressure measurement catheter was placed at the choana of the tested side, and the position was confirmed endoscopically. Repeatability was tested among nasal cavities, specimens, and repeat setups. Pressure measurements were taken incrementally between 0 and 25 liters per minute (Lpm) at each of three conditions: 1) control state, without augmentation, 2) simulated IT hypertrophy with 20% benzocaine topical anesthetic gel filler placed within sub-periosteal flap, and 3) out-fractured, reduced inferior turbinates. Results: The experimental system was simple to set up and repeatable. Experimentally, nasal airway resistance measurements revealed decreased resistance under control and out-fractured configuration versus hypertrophied turbinates. Initial studies trended, under all conditions, to have exponential growth of pressure as flow rate increased. Conclusions: The physiologically isolated test system allows anatomic manipulation and measurement of resulting pressure-flow relationships. IT alterations resulted in expected pressure-flow changes, indicating future analysis at other anatomic locations, such as olfactory epithelium, septum, or middle turbinate, is feasible.

Physiologic assessment of allergic rhinitis in mice: Role of the high-affinity IgE receptor (FcɛRI)

There have been few reports using animal models to study the development of allergic rhinitis. Characterization of such a model in mice would be advantageous given the availability of reagents and gene-manipulated strains. We sought to develop a murine model of allergic rhinitis in the absence of lower airway changes. After sensitization and challenge, both wild-type and FcepsilonRI-deficient mice were studied for their ability to develop early- and late-phase nasal responses. In the invasive approach, direct measurements of nasal airway resistance (R(NA)) were obtained; in the noninvasive approach using whole-body plethysmography, respiratory frequency and expiratory and inspiratory times were monitored. In both approaches, nasal responses were determined either acutely after challenge (early phase) or 24 hours after challenge (late phase). After challenge of sensitized mice, R(NA) significantly increased. In parallel, respiratory frequency significantly decreased and was highly correlated with the increases in R(NA). Sensitized wild-type mice had an early-phase nasal response and persistent nasal blockage (late-phase response) after allergen challenge. In contrast, sensitized and challenged FcepsilonRI alpha-chain-deficient mice did not have an early-phase nasal reaction and exhibited reduced nasal blockage and lower IL-13 levels in nasal tissue homogenates. These data indicate that FcepsilonRI is essential to development of an early-phase nasal response and contributes to the development of the late-phase nasal response. These invasive and noninvasive approaches provide new opportunities to evaluate the mechanisms underlying the development of nasal responses to allergen and to assess various therapeutic interventions.

A prospective study using rhinomanometry and patient clinical satisfaction to determine if objective measurements of nasal airway resistance can improve the quality of septoplasty.

In the ENT Department of University Central Hospital, Turku, the waiting list for elective septoplasty grew to 4 to 5 years in the late 1980s. Therefore, a prospective clinical project was initiated during which all patients waiting for septal surgery were re-examined and nasal airway function was measured with rhinomanometry. Patients with high nasal resistance or other specific indications for nasal obstruction were selected for surgery (n = 432). The remaining patients were excluded from surgery and followed up (n = 284). Results showed that if patients were referred for septal surgery without rhinomanometric study, about 10% became symptom-free within 3 to 5 years. Patients operated on after defining a high preoperative intranasal resistance had a higher postoperative satisfaction level (85%) than those operated on with normal nasal resistances but other indications for correcting the nasal septum (69%). After 3 years, the majority of patients not treated surgically were satisfied with their conservative treatments, although certain patients still required some form of nasal surgery to relieve recurring nasal and/or sinus complaints.

Seasonal Variations of Nasal Resistance in Allergic Rhinitis and Environmental Pollen Counts. III: Efficacy of Antiallergic Agents

We previously reported that, in a patient with Japanese cedar pollinosis, preseasonal increase in total nasal airway resistance (NAR) possibly caused from circannual endogenous rhythm was suppressed by preseasonal systemic administration of antiallergic agent. In this study, in order to determine the influence of preseasonal use of a topical antiallergic agent and seasonal administration of a peroral antiallergic agent, we made measurement of nasal airway resistance and pollen counts under the previous respective conditions in separated years. Preseasonal high mean values of total NAR for a couple of weeks was not suppressed by the preseasonal topical administration of ketotifen nasal spray in 1992 which was a low pollen season (974/cm2). However, the patient did not complained of severe episodes of hay fever at all throughout the season. Preseasonal increases in mean values of total NAR were observed in 1993 which was a high Japanese cedar pollen season (4,875/cm2) with NAR the same as untreated seasons. This may have been because the patient was not treated with preseasonal use of peroral azelastine. On extremely high Japanese cedar pollen count days further increased NAR occurred in the patient. The patient experienced relatively severe hay fever episodes, but used no other anti-histamine nor topical steroid during the season.

Seasonal Variations of Nasal Resistance in Allergic Rhinitis and Environmental Pollen Counts

We made measurements of nasal airway resistance in a patient with Japanese cedar pollinosis and also measured the environmental pollen counts under different exposure conditions. In the season of high Japanese cedar pollen counts in Japan values of mean nasal airway resistance were significantly increased, remained elevated for 2 months after the season, and eventually decreased. In the season of low pollen counts, the mean values of nasal airway resistance measurements were increased during the season but decreased more rapidly after the season. In a year with no exposure to the environmental allergen because the subject lived out of Japan, the mean nasal airway resistances were relatively increased closely in phase with the Japanese cedar pollen season.

Normal nasal airway resistance in noses of different sizes and shapes

Measurement of nasal airway resistance is becoming a common clinical technique. Accurate definition of the normal range of airflow is critical for maximal usefulness of this technique. Since typical nasal size and shape vary greatly with ethnic background, different norms for different ethnic groups may be appropriate. Nasal airway flow and resistance and external nasal size and shape were measured in 130 asymptomatic subjects (52 black, 56 white, and 22 Hispanic). Nasal length, width, columellar length, and nasolabial angle were similar for whites and Hispanics, but both groups differed significantly from blacks--even when changes attributable to biologic aging were factored out. In spite of these differences, there was no significant difference in any nasal airflow or resistance parameter among groups, suggesting that currently used airflow and resistance standards are valid for these three different ethnic groups.

Indoor and outdoor pollutants and the upper respiratory tract

The health effects of both indoor and outdoor air pollutants are of increasing concern. The health effects of outdoor air pollutants traditionally have been assessed through measurements of lower respiratory tract changes. However, it has been shown that one outdoor air pollutant, sulfur dioxide, decreases nasal mucus flow and increases nasal airway resistance. Along with cigarette smoke, indoor air pollutants such as formaldehyde, cadmium, and ammonium or sulfate ions have been shown to alter upper airway mucociliary function. Emissions from wood stoves are known to irritate the upper airways. Measurement of nasal airway resistance using posterior rhinomanometry allows quantification of nasal function. This technique recently has been used to demonstrate that adolescents with allergic asthma have increased work of breathing after inhalation of 0.5 ppm sulfur dioxide. Another study using posterior rhinomanometry showed that clerical workers had increased work of breathing after exposure to carbonless copy paper as compared with bond paper. This brief review of upper respiratory tract changes after pollutant exposure should serve as a reminder that a complete clinical history must include questions designed to ascertain the patient's exposure history to both outdoor and indoor air pollutants. These exposures can have a major impact on the health of the upper respiratory system.

Influence of topical phenylpropanolamine on tachyphylaxis and mucociliary clearance in the human nose.

Topical nasal phenylpropanolamine in a 2.5 per cent solution (PPA) was used in an evaluation of the possible development of tachyphylaxis and of possible effects on the mucociliary system after one week of treatment in healthy humans. The tendency of PPA to produce tachyphylaxis was evaluated by rhinomanometrie measurements of nasal airway resistance after repeated dose-response provocations. The mucociliary transport time was tested with the saccharine-dye test. No reduced dose-response effect or change in mucociliary transport time was found with PPA, thus indicating that one week of treatment does not contribute to such adverse effects.

Nasal provocation testing: An objective assessment for nasal and eustachian tube obstruction

Nasal provocative testing is the introduction of a specific factor into the nose and the subsequent assessment of the pathophysiologic changes induced by the challenge. The provocative test primarily affects the nasal airway but also may affect the adjacent organs, including the eustachian tube, middle ear, sinuses, and lower respiratory tract. Recent advances in the measurement of nasal airway resistance with microcomputer-assisted rhinomanometry have improved the objective assessment of nasal airway obstruction. Eustachian tube obstruction has been shown after nasal provocation by a new procedure, sonotubometry, which can be performed in series with rhinomanometry and pulmonary spirometry. As will be described these procedures have helped elucidate the extent and pathophysiology of diseases affecting the upper airway, especially allergic rhinitis. At present, nasal provocation is primarily a clinical investigative test. It is anticipated that with further development and refinement, it can be used to a greater extent in the diagnosis and management of nasal diseases.

Nasal airway response to mucosal perfusion and outflow resistance in the dog and rat.

Simultaneous measurements of nasal airway resistance and vascular perfusion of the nasal mucosa were carried out in the dog and rat. Nasal blood flow (perfusion pressure) and nasal venous pressure (jugular venous pressure) were found to have a linear correlation with nasal airway resistance. The slope of the percentage change in nasal airway resistance to perfusion pressure was 0.03 to 0.04%/mmHg and resistance to nasal venous pressure, 1.15 to 1.28%/mmHg. The results therefore indicate that alterations in venous outflow resistance are more effective than alterations in arterial inflow in changing nasal airway resistance.

NASAL RESISTANCE AND NASAL HISTAMINE CHALLENGE IN ALLERGIC SUBJECTS STUDIED BY POSTERIOR RHINOMETRY

Posterior rhinometry allows quantitative measurement of nasal airway resistance and nasal power. We used this research tool in two separate studies. Initially 10 atopic and 6 nonatopic adults had nasal resistance and nasal power measured at 2 hour intervals for 6 hours on two separate days. A computer digital program was used to collect and analyze the data. Statistical analysis showed considerable intra subject and inter subject variability as well as significantly higher mean measurements of nasal resistance in the allergic population. Nonatopic subjects showed very constant lower values for nasal resistance. We then evaluated whether intranasal insufflation of histamine would cause eustachian tube dysfunction (ETD) in atopic adults. These subjects had normal baseline nasal power measurements by posterior rhinometry and normal eustachian tube function by swallow test. All had quantifyable changes in nasal power after a single dose of 0.55 mgm histamine delivered into each nares for 6 seconds. Four of the five atopic subjects had eustachian tube obstruction documented by 9-step tympancmetry within 5 to 20 minutes after peak nasal power was recorded. In both studies, posterior rhinometry was a useful tool to objectively quantify measurement of nasal resistance so that we could document the higher and more variable measurements found in atopic patients and correlate nasal resistance changes caused by histamine with ETD in these patients.

A technique for measuring the perception of added resistive loads during nasal breathing

The perception of resistive loads added to nasal breathing was assessed in ten healthy adults using established psychophysical methods previously described for oral breathing. Detection threshold, that is, the smallest incremental resistance that the subject could detect 50% of the time, was determined at three different time periods (0, 30, and 60 min) on two separate days to determine the reproducibility of values over time. Nasal airway resistance measurements were made before and after threshold determinations to determine the influence of baseline resistance on the ability to detect added loads as well as to assess any effects of the procedure itself on resting nasal airway resistance. Analyses of the data revealed that subject-to-subject differences were the largest source of variability in threshold values followed by time period-to-time period differences and day-to-day variability. Although it was the smallest variability source, day-to-day variability still was significantly greater than zero. In contrast to previously published resports on resistive load detection during mouth breathing, the degree of baseline resistance did not appear to influence the subject's ability to detect added resistive loads during nasal breathing. These techniques may provide a methodological basis for objectively evaluating the effects of pharmacologie agents on perceived nasal patency.

Nasal methacholine challenge: A test for the measurement of nasal reactivity

The aim of this study was to develop a test for the measurement of nasal reactivity. Different concentrations of methacholine were sprayed intranasally, and the nasal secretion and blockage were measured in normal subjects. The simple collection and measurement of secretion was found to be a valuable parameter of mucosal reactivity, while measurement of nasal airway resistance was unreliable, due in part to the presence of secretion in the nasal cavity. The methacholine test had a fairly good reproducibility when the amount of secretion was used as the only parameter. It caused a significantly stronger reaction in women than in men. Patients with perennial rhinitis had a more vigorous response than the controls. It is concluded that the methacholine test may prove useful as a sign of perennial rhinitis and also for the objective evaluation of medication, but further studies are warranted.

Nasal airway resistance computer.

An analogue computing system for the measurement of nasal airway resistance (Rn) has been developed. The instrument operates on the principle of measuring the transnasal pressure required to generate a measured nasal airflow rate. The system computes and displays inspiratory or expiratory nasal airway resistance measured at a preselected flow rate. The values are updated on a breath-by-breath basis and presented to a multi-channel recorder and a digital panel meter for visualization. The continuous Rn (at all inspiratory and expiratory flow rates above zero) can also be recorded. Use of the instrument for the evaluation of nasal decongestants has been demonstrated.

Animal models for evaluation of compounds against influenza viruses.

Experimental methods for the evaluation of antiviral compounds in mice and ferrets infected with influenza viruses are discussed. BRL 5907, an interferon inducer, is shown to reduce lung lesions in infected mice and the behaviour of standard antiviral compounds is compared using their capacity to reduce the increase in lung weight caused by the virus. In infected ferrets, BRL 5907 reduces the febrile response and virus excretion while allowing full humoral antibody production. Measurement of nasal airway resistance is shown to be a reproducible method of monitoring respiratory distress in infected ferrets.

Measurement of nasal airway resistance: methods and normal values

Drug Prescribing for Patients with Chronic Kidney Disease in General Practice: a Cross-Sectional Study

A method for the measurement of nasal airway resistance.

A method for the measurement of nasal airway resistance.

Measurement of nasal airway resistance

A measure of nasal airway resistance can be obtained by simultaneously relating transnasal pressure drop and the rate of nasal air flow. Resistance varies continuously throughout the range of attainable flows, and it has meaning only in relationship to specified rates of flow at which it is measured. The procedure described appears to provide a usable objective parameter for evaluating nasal response to controlled allergenic challenge and to other test situations.