Total Nasal Airway Resistance Research Articles

Columellar strut grafts versus septal extension grafts during rhinoplasty for airway function, patient satisfaction and tip support

Different techniques exist to provide tip support in rhinoplasty. There is little evidence to provide a consensus on the most effective choice.Evaluating columellar strut graft (CSG) and septal extension grafts (SEG) for their influence on airway function, patient satisfaction and tip support.A retrospective cohort study was undertaken on 165 adult patients who underwent open rhinoplasty with either a CSG or SEG, from February 2012 to August 2019 in a single tertiary facial-plastic practice in Sydney, Australia. Operations were for both cosmetic and functional indications, and both primary and revision cases were assessed. Airway testing and patient-reported outcomes (PROMs) were performed preoperatively and at least 6 months following the procedure. Photographic tip analysis was taken from approximately 4 and 12-month postoperative photographs.Nasal peak inspiratory flow (NPIF) and total nasal airway resistance (NAR) were the primary airway functional outcomes. The primary PROMs analysed were a visual analogue scale (VAS) for nasal obstruction and 13-point Likert scale for global cosmesis, the Nose Outcome Symptom Evaluation (NOSE), and the nasal obstruction score. Tip support was determined by the nasolabial angle (NLA) and Simon's ratio as assessed by Rhinobase developed by Apaydin et al. on lateral Frankfort plane photographs. Data normalised as an improvement over preoperative baseline, accounting for individual variability.A total of 165 patients was assessed (35.2 ± 12.9 yrs, 72% female), 100 (61%) of which received SEG. There were similar nasal airway assessments between CSG and SEG groups, with ΔNPIF (20.0 ± 42.1 L/min v 19.9 ± 44.9 L/min, p = 0.983) and Δ "obstructed" NAR (-1.13 ± 1.90 v -1.02 ± 4.33 Pa/cm3/s, p = 0.849). Amongst PROMs, a greater cosmetic outcome was seen in the SEG group (7.20 ± 2.97 v 5.69 ± 3.45, p < 0.01) with all other assessments similar between CSG and SEG techniques. Photographic analysis of tip projection showed reduced NLA distortion in the SEG.While greater patient-perceived cosmesis was seen in patients with a SEG, there were similar airflow and patient-reported nasal function between groups. Photographic analysis of tip projection showed SEG patients additionally benefited from less NLA distortion and greater tip maintenance.

Objective assessment of nasal resistance among electronic cigarette users.

Electronic cigarettes have been a popular alternative to tobacco smoking. The effect of tobacco smoking on nasal airway resistance has been investigated before; however, the effect of the aerosol generated by electronic cigarettes is still unknown. This study aimed to evaluate the short-term effects of e-cigarettes on nasal airway resistance. Sixty-one participants were recruited into a vapers group and a control group. The vapers group was instructed to smoke for 5 minutes, and their nasal resistance was measured pre-procedure and at 1 and 5 minutes post-procedure. The results were compared between both groups. Repeated measures analysis of variance demonstrated that vaping has no statistically significant effect on total nasal airway resistance. Although the differences between both groups were not statistically significant overall, the vapers group showed a reduction in nasal airway resistance in the short term.

Total nasal airway resistance while sitting predicts airway collapse when lying down.

Nasal obstruction when lying down is a common complaint in patients with chronic nasal obstruction, but rhinomanometry is typically performed in the sitting position. This study aimed to analyse whether adding rhinomanometry in a supine position is a useful examination. A total of 41 patients with chronic nasal obstruction underwent rhinomanometry and acoustic rhinometry, sitting and supine, before and after decongestion, as well as an over-night polygraphy. Total airway resistance was measurable in a supine position in 48 per cent (14 of 29) of the patients with total airway resistance of equal to or less than 0.3 Pa/cm3/second when sitting and in none (0 of 12) of the patients with total nasal airway resistance of more than 0.3 Pa/cm3/second when sitting. After decongestion, this increased to 83 per cent and 58 per cent, respectively. Increased nasal resistance when sitting predicts nasal breathing problems when supine. Rhinomanometry in a supine position should be performed to diagnose upper airway collapse when supine.

Evaluation of nasal obstruction in lowlander males in high altitude

BackgroundNasal symptoms are a major problem affecting the quality of life of lowlanders deployed at high altitude. Study was carried out in fresh male inductees inducted in high altitude of 11,500ft (3500m) above sea level to evaluate the nasal obstruction using the subjective Nasal obstruction and symptom evaluation (NOSE) score and rhinomanometry during the stay in high altitude. MethodsA prospective study was carried out in 100 males inducted into high altitude. The subjects were evaluated using the subjective assessment tool, NOSE scale and rhinomanometry on induction and after 2 months. The data were analysed for NOSE scale in the 1st and 2nd visit by test for equality of proportions and the total nasal airway resistance (Pa) has been expressed as mean±standard deviation and compared across severity of NOSE score using one way ANOVA and between 1st and 2nd visit using paired t test. Results and conclusionsOut of the 100 subjects, 77 came for the 2nd review after 2 months. There was statistically significant worsening in the subjective feeling of nasal obstruction during the stay in high altitude without any significant change in the nasal airway resistance.

Impact of Hatha Yoga on the Airway Resistances in Healthy Individuals and Allergic Rhinitis Patients.

There have been limited studies on Hatha yoga training as a complementary therapy to manage the symptoms of Allergic Rhinitis. The main Aim of the study was to check the impact of Hatha yogasanas on the Airway resistances in Healthy volunteers, a baseline data can be established and also to study the impact of Hatha yogasanas on the Airway resistances in Allergic Rhinitis patients in Bangalore, India. This is a prospective case series of 51 healthy volunteers (18 Males and 33 Females) Group 1 and 51 Allergic Rhinitis patients (18 Males and 33 Females) Group 2. The Objective analysis of the upper airway resistance was measured using a rhinomanometer and the lower airway resistance was measured using a spirometer. Then the subjects practiced specific Hatha yogasanas for three months. Then the airway resistance tests were again done at 3months interval. The subjective analysis was done pre yoga and post yoga using the Short form-12 (SF-12) and Sino Nasal Outcome Test (SNOT) Questionnaires to assess the quality of life. The data was analyzed by doing a Paired (2-tailed) T Test, using SPSS (Software Package for Social Sciences) version 16. Total Nasal Airway Resistance pre yoga and post yoga in 51 healthy volunteers had significantly reduced at 150Pa and the Forced Vital Capacity(FVC) pre yoga and post yoga had significantly increased,Forced Expiratory volume (FEV1) & % Residual standard deviation (%RSD) had increased but not significant. The Physical component score (PCS) and Mental component score (MCS) of the SF-12 health survey questionnaire had significantly improved with and the SNOT questionnaire score had significantly reduced. The Total Nasal Airway Resistance in 51 Allergic Rhinitis had significantly reduced at 150Pa and the FVC pre yoga and post yoga showed increase but change was not significant, FEV1 pre yoga and post yoga had significantly increased, %RSD pre yoga and post yoga had significantly increased. The PCS and MCS of the SF-12 health survey questionnaire had significantly increased and the SNOT questionnaire score had significantly decreased. The scientific documentation of the impact of Hatha Yoga on the airway resistances can be an eye opener in the management of several other diseases of the airways.

Effects of a Mask on Breathing Impairment During a Fencing Assault: A Case Series Study.

Background:Fencers often complain of progressive difficulty in breathing during matches, which is generally attributed to restricted air, light and heat circulation from wearing a mask. Physiologically, the nasal structure generates airflow resistance that can reach -50% of the total respiratory resistance.Objectives:This study aims to investigate the presence of nasal obstruction in fencers and the relationship with the use of mask.Materials and Methods:An observational study on 40 fencers (18 males, 22 females) was conducted. Fencers perform a usual assault, wearing the mask and standardized physical exercises (running, sprints and obstacles) without the mask. ENT examination with a nasal flexible fiberscope, Anterior Active Rhinomanometry (AAR) and Peak Nasal Inspiratory Flow (PNIF) measurement before and after physical activity with or without the mask was recorded.Results:Before physical exercise, the total nasal airway resistance mean value for AAR was 0.33 ± 0.17 Pa/cm3/s at 150 Pa. After a match with the mask, the mean value was 0.28 ± 0.16 Pa/cm3/s. After normal physical exercises without mask, the mean value was 0.24 ± 0.15 Pa/cm3/s. Using t tests, statistically significant difference between nasal resistance before and after physical activity (P < 0.05) was observed, but no significant difference in nasal resistance between the basal value and that taken after a match wearing the masks (P = 0.1265). PNIF values significantly increase with exercise (P < 0.05).Conclusions:Our study shows that wearing the mask causes increased breathing impairment in fencers, when compared with similar physical activity without the mask.

Effects of a Mask on Breathing Impairment During a Fencing Assault: a Case Series Study

Background: Fencers often complain of progressive difficulty in breathing during matches, which is generally attributed to restricted air, light and heat circulation from wearing a mask. Physiologically, the nasal structure generates airflow resistance that can reach -50% of the total respiratory resistance. Objectives: This study aims to investigate the presence of nasal obstruction in fencers and the relationship with the use of mask. Materials and Methods: An observational study on 40 fencers (18 males, 22 females) was conducted. Fencers perform a usual assault, wearing the mask and standardized physical exercises (running, sprints and obstacles) without the mask. ENT examination with a nasal flexible fiberscope, Anterior Active Rhinomanometry (AAR) and Peak Nasal Inspiratory Flow (PNIF) measurement before and after physical activity with or without the mask was recorded. Results: Before physical exercise, the total nasal airway resistance mean value for AAR was 0.33 ± 0.17 Pa/cm3/s at 150 Pa. After a match with the mask, the mean value was 0.28 ± 0.16 Pa/cm3/s. After normal physical exercises without mask, the mean value was 0.24 ± 0.15 Pa/cm3/s. Using t tests, statistically significant difference between nasal resistance before and after physical activity (P < 0.05) was observed, but no significant difference in nasal resistance between the basal value and that taken after a match wearing the masks (P = 0.1265). PNIF values significantly increase with exercise (P < 0.05). Conclusions: Our study shows that wearing the mask causes increased breathing impairment in fencers, when compared with similar physical activity without the mask.

Combined radiofrequency volumetric tissue reduction and lateral outfracture of hypertrophic inferior turbinate in the treatment of chronic rhinitis: short‐term and long‐term outcome

Radiofrequency volumetric tissue reduction (RFVTR) of hypertrophic inferior turbinate (IT) is an effective way to treat patients with intractable nasal mucosal obstruction. We evaluated the effectiveness of combined RFVTR and lateral outfracture (LO) of hypertrophic IT in chronic rhinitis (CR) patients on reduction of nasal obstruction, rhinorrhea, and nasal pruritus both short and long term. Seventy-three patients with CR who failed medical treatment were recruited to undergo combined RFVTR and LO of hypertrophic IT. Nasal congestion scores were recorded before the operation, and immediately, 2 weeks, 6 weeks, 3 months, 6 months, 1 year, 2 years, and 3 years after the operation. Rhinorrhea and pruritic score as well as total nasal airway resistance (TNAR) and total nasal airflow (TNAF) (measured by active anterior rhinomanometry) were recorded before the operation, and 2 weeks, 6 weeks, 3 months, 6 months, 1 year, 2 years, and 3 years after the operation. Forty-five patients completed the follow-up period of 3 years. Subjects consisted of 25 male and 20 female patients, with an average age of 31 years. Nasal congestion scores were significantly improved immediately after the operation. Nasal congestion scores and TNAR values were significantly decreased whereas TNAF values were significantly increased at every time point postoperatively. Rhinorrhea and pruritic scores were also significantly improved at every time point after 2 weeks postoperatively. Combined RFVTR and LO of hypertrophic IT is an effective treatment for nasal obstruction, rhinorrhea, and nasal pruritus in CR and the result lasts up to 3 years postoperatively.

Anterior Rhinomanometry and Determination of Nasal Mucociliary Clearance Time With the Saccharin Test in Children With Crimean-Congo Hemorrhagic Fever

Crimean-Congo hemorrhagic fever (CCHF), like other viral infections, may prolong mucociliary clearance time and increase nasal resistance in children. The aim of the present prospective case-control study was to study, using saccharin and anterior rhinomanometry tests, whether CCHF infections caused any change in nasal physiology. Overall, 40 subjects, 20 of whom had CCHF (group 1) and 20 of whom were healthy controls (group 2), were enrolled in this study. The definitive diagnosis of CCHF infection was made based on typical clinical and epidemiological findings and detection of CCHF virus-specific IgM by ELISA or of genomic segments of the CCHF virus by reverse transcription-polymerase chain reaction. Anterior rhinomanometry was performed in all participants according to current recommendations of the Committee Report on Standardization of Rhinomanometry. A saccharin test was used to evaluate mucociliary clearance, and nasal mucociliary clearance time was assessed with the saccharin test as described previously. In our patients, the mean time from the application of saccharin crystals to the first feeling of a sweet taste was 6.77 ± 3.25 minutes (range 2-16 min). In terms of the mean time from the application of saccharin crystals to the first feeling of a sweet taste, there was no difference between two groups. The mean total air flow was 637.60 ± 76.18 mL/s (range 490-760 mL/s). The mean total nasal airway resistance was 0.24 ± 0.03 Pa/mL s (range 0.20-0.31 Pa/mL s). In terms of the degree of nasal air flow and nasal airway resistance and the total air flow and total nasal airway resistance of each nostril, there was no difference between the 2 groups. The results obtained in anterior rhinomanometry and saccharin test showed that there was no statistically significant difference between CCHF (+) patients and controls. These results suggest us that CCHF virus infection does not affect nasal physiology. However, this is the first study performed on this issue and further studies on larger series need to be performed.

Correlation between nasal nitric oxide, nasal airway resistance and atopy in patients of allergic rhinitis

Background: Nasal airway resistance (NAR) is dependent upon the tone of the nasal vasculature, which is regulated by endothelially derived nitric oxide (NO). Aim: The aim of this study was to investigate the relationship between nasal nitric oxide (nNO) levels, NAR and atopy in patients of allergic rhinitis (AR). Materials and Methods: The subjects were assessed for nNO levels by NIOX chemiluminescence analyzer. NAR was measured by 4-Phase-Rhinomanometry using RHINOTEST 1000. Atopy was assessed by skin prick testing against 58 common aeroallergens. Statistical Analysis: SPSS, Chicago, IL, USA, statistical package version 14 using independent sample t-test and Pearson correlation Results: In the study, 15 diagnosed cases of AR and five healthy volunteers as control were included. In the control group, the mean total NAR was 0.16 ± 0.08 kPa/l/s while in AR group mean total NAR was 0.22 ± 0.1 kPa/ l/s (P = 0.4). In AR group mean left and right NAR were 0.50 ± 0.28 kPa/l/s and 0.52 ± 0.4 kPa/l/s respectively and mean nNO levels of right and left nostrils were 291.2 ± 122.90 ppb and 251 ± 171.16 ppb (P = 0.7). No correlation was found between the left or right unilateral NAR and nNO levels, respectively. Similarly, no significant correlation of unilateral NAR and NO levels were found in the control group. Atopic AR patients had higher NAR (P = 0.001) and nNO (P = 0.06) compared with non-atopic rhinitis patients. Conclusion: In our study, AR group had higher NAR, but no correlation was found between nNO and NAR in either groups. The atopic AR patients had significantly higher NAR in comparison with non-atopic patients.

Objective and subjective assessments of nasal obstruction in children and adolescents with allergic rhinitis

To correlate objective assessment of nasal obstruction, as measured by acoustic rhinometry (volume of the first 5 cm of the nasal cavity) and active anterior rhinomanometry (total nasal airway resistance), with its subjective evaluation (obstruction scores). Thirty patients, aged 7 to 18 years, with persistent allergic rhinitis and thirty controls were enrolled. The obstruction score was reported for the whole nasal cavity and for each nostril separately. The three variables were measured at baseline and after induction of nasal obstruction. There were significant and negative correlations between resistance and nasal volume in all groups and scenarios, except for the most obstructed nostril, in the control group, post-obstruction. For the whole nasal cavity, there was no significant correlation between objective and subjective variables except between score and total nasal cavity volume in the control group, post-obstruction. Regarding the most obstructed nostril, we found a significant negative correlation between score and resistance and a significant positive correlation between score and volume for the total group at baseline. There were no clear differences in the correlation coefficients found in patients and controls. The correlation coefficients did not change after induction of nasal obstruction. Objective assessment of nasal obstruction did not correlate significantly with subjective evaluation for the nasal cavity as a whole, but there was a correlation for unilateral assessments. There was correlation between the objective evaluations. Allergic rhinitis and acute induction of nasal obstruction did not affect the correlation between objective and subjective assessments of nasal obstruction. Addition of an objective method for evaluation of nasal obstruction could be useful in the research setting; if no such method can be used, each nostril should be evaluated separately.

The relationship between nasal index and nasal airway resistance, and response to a topical decongestant

The differences in the shape and size of the nose have been proposed to be an adaptation to climate with broad noses (platyrrhine) evolving in a warm humid environment where there was little need for air conditioning and narrow noses (leptorrhine) evolving in colder climates where the air needed more warming. The main aim of this research was to determine if there was any relationship between the shape of the nose as expressed in terms of nasal height and width (nasal index) and total nasal airway resistance (NAR), as one would predict that the narrower leptorrhine noses would have a greater resistance to air flow than the broader platyrrhine noses. It was also proposed that the narrow leptorrhine nose would have better developed vascular tissue than the broad platyrrhine nose in order to condition cold air, and would exhibit a greater response to nasal decongestion. No correlation was found between nasal index and NAR (r = -0.09) and similarly no correlation was found between nasal index and response to a topical nasal decongestant (r = 0.02). The absence of any physiological differences between the different nose types may be due to acclimatisation of participants to the area of recruitment.

The relationship between nasal index and nasal airway resistance, and response to a topical decongestant

The differences in the shape and size of the nose have been proposed to be an adaptation to climate with broad noses (platyrrhine) evolving in a warm humid environment where there was little need for air conditioning and narrow noses (leptorrhine) evolving in colder climates where the air needed more warming. The main aim of this research was to determine if there was any relationship between the shape of the nose as expressed in terms of nasal height and width (nasal index) and total nasal airway resistance (NAR), as one would predict that the narrower leptorrhine noses would have a greater resistance to air flow than the broader platyrrhine noses. It was also proposed that the narrow leptorrhine nose would have better developed vascular tissue than the broad platyrrhine nose in order to condition cold air, and would exhibit a greater response to nasal decongestion. No correlation was found between nasal index and NAR (r = -0.09) and similarly no correlation was found between nasal index and response to a topical nasal decongestant (r = 0.02). The absence of any physiological differences between the different nose types may be due to acclimatisation of participants to the area of recruitment.

Assessment of Nasal Airflow Resistance in the Healthy Population of Chattisgarh by Active Anterior Rhinomanometry

The aim of present study was to define a normal range of total nasal airflow resistance in the healthy population of Chattisgarh. This study was conducted at the Department of Otorhinolaryngology, Medical College Raipur, Chattisgarh over 93 healthy adults. A proper otolaryngology examination was done prior to the study and all the subjects were free from any type upper respiratory tract infection. This was the main inclusion criteria for the present study. All the subjects were distributed according to age and sex. Active Anterior Rhinomanometry is the best recommended method for evaluating the objective assessment of nasal airflow resistance; it was preferred for the assessment of total nasal airway resistance in present study also. The present study concluded that the mean value of total nasal airway resistance was 0.21 at 150Pa pressure. However the range of total nasal airway resistance was from 0.142 to 0.34Pa/cm(3)/s at the same pressure. The present study presents the normal range and mean value of total nasal airway resistance for the healthy adult population of Chattisgarh. Total nasal airway resistance is independent of age and sex.

Rhinomanometry in young patients with perennial allergic rhinitis with/without recent exposure to tobacco smoke

To assess the influence of environmental exposure to tobacco smoke on the nasal symptoms and nasal resistance of young patients with perennial allergic rhinitis. Cross-sectional study. Tertiary referral centre. Fifty patients were evaluated (aged 10-19 years old): 25 patients with and 25 patients without recent exposure to tobacco smoke (confirmed by cotinine/creatinine ratio). After a clinical evaluation, all the patients replied to a validated questionnaire of the severity of the nasal symptoms. Then total nasal airway resistance was recorded by active anterior rhinomanometry. Patients with exposure to tobacco smoke had a larger total resistance than patients without exposure (t-test, P < 0.01). No significant correlation was observed between the total score of the questionnaire of nasal symptoms and the nasal resistance. In young patients with perennial allergic rhinitis, exposure to tobacco smoke can be related to increased nasal resistance, which may not be recognised by the report of nasal symptoms.

Re: Correlation between subjective and objective evaluation of the nasal airway. A systematic review of the highest level of evidence

Background: There is no consensus about the value of objective measurements of nasal patency. Objective: To assess the correlation between the subjective sense of nasal patency and the outcomes found with rhinomanometry and acoustic rhinometry. Type of review: Structured literature search. Search strategy and evaluation method: Review of English-language articles in which correlations were sought between subjective nasal patency symptoms and objective scores as found with rhinomanometry [nasal airway resistance (NAR)] and acoustic rhinometry [minimal cross-sectional area (MCA)]. Correlations were related to unilateral or combined assessment of nasal passages and to symptomatic nasal obstruction or unobstructed nasal breathing. Results: Sixteen studies with a level of evidence II-a or II-b fit the inclusion criteria and were further analysed. Almost every possible combination of correlations or lack thereof in relation to the variables included was found. However, when obstructive symptoms were present, a correlation between the patency symptoms with nasal airway resistance and minimal crosssectional area was found more often than in the absence of symptoms. In cases of bilateral assessment a correlation was found almost as often as it was not between patency symptoms and total nasal airway resistance or combined minimal crosssectional areas, while in the limited amount of studies in which unilateral assessment was done a correlation was found each time between patency symptoms and nasal airway resistance. Conclusions: The correlation between the outcomes found with rhinomanometry and acoustic rhinometry and an individual’s subjective sensation of nasal patency remains uncertain. Based on this review, it seems that the chance of a correlation is greater when each nasal passage is assessed individually and when obstructive symptoms are present. There still seems to be only a limited argument for the use of rhinomanometry or acoustic rhinometry in routine rhinologic practice or for quantifying surgical results. Clin. Otolaryngol. 2009, 34, 518–525.

Cytology of nasal mucosa, olfactometry and rhinomanometry in patients after CO2 laser mucotomy in inferior turbinate hypertrophy.

To evaluate the cytology of nasal mucosa and sense of smell and nasal patency in patients underwent carbon dioxide laser turbinoplasty (CO2 laser mucotomy) due to chronic nasal hypertrophy. 46 patients with inferior turbinate hypertrophy underwent complete laryngological examination, anterior rhinomanometry, olfactory measurements and cytology of nasal mucous which were performed before and 3 months after CO2 laser mucotomy. Laser mucotomy was performed under local anesthesia. Cytograms revealed significant changes in cell proportion before and after the surgery. Goblet cells predominated in nasal smears before the laser mucotomy. An average percentage of eosinophils in evaluated cytograms before the surgery was 2.1%. Three months after laser mucotomy we observed decrease in goblet cells proportion (the mean range of goblet cells was 16.4%) in nasal cytology. We have also observed improvement in olfactory function, however only in 7 patients (20.6%). The mean value of total nasal airway resistance (NAR) before treatment was 0.98+/-0.24 Pa/cm3/s at 75 Pa. Rhinomanometry after 3 months showed a reduction in mean total resistance from the pretreatment level to 0.77 Pa/cm3/s. We believe that CO2 laser mucotomy is an efficacious, minimally invasive and easy to use treatment of inferior turbinate hypertrophy which is performed under local anesthesia with little discomfort for the patient and does not require hospitalization.

Intranasal Steroids Delay Repeat Polypectomy Events

OBJECTIVE: To identify the prognostic factors that may affect the outcome of endoscopic sinus surgery (ESS) in chronic rhinosinusitis (CRS). METHOD: Study design: Prospective study 68 patients having CRS were studied (over a priod of 2 years) including history taking, endoscopic examination, CT and measurement of nasal nitric oxide (nNO),nasal carbon monoxide (nCO) and total nasal airway resistance. All patients underwent ESS. The specimens were studied histopathologically (for eosinophilia)and bacteriologically (for intracellular S. aureus). RESULTS: Intracellular S. aureus, old age, tissue eosinophilia, and Widal syndrome were found to be associated with a less favorable long-term outcome. In contrast, anatomic variants, allergy, bronchial asthma, and smoking do not seem to affect the prognosis of ESS in patients with CRS. Post-operatively, there was a significant increase in nNO and decrease in nCO production. Patients with polyposis showed less nNO level and olfactory threshold, but higher CT and endoscopic scores. The CT score correlated positively with the endoscopic score, the surgery score, and the degree of tissue eosinophilia. CONCLUSION: 1) The prognostic factors that may affect the outcome of ESS in CRS have been identified. 2) The postoperative increase in nNO and decrease in nCO levels raises the question of whether they can be used to monitor the treatment of CRS like their use in bronchial asthma or not. 3) The olfactory deficit in patients with polyposis is most likely due to mucosal inflammation rather than airway obstruction.

Correlation between subjective and objective evaluation of the nasal airway. A systematic review of the highest level of evidence

There is no consensus about the value of objective measurements of nasal patency. To assess the correlation between the subjective sense of nasal patency and the outcomes found with rhinomanometry and acoustic rhinometry. Structured literature search. SEARCH STRATEGY AND EVALUATION METHOD: Review of English-language articles in which correlations were sought between subjective nasal patency symptoms and objective scores as found with rhinomanometry [nasal airway resistance (NAR)] and acoustic rhinometry [minimal cross-sectional area (MCA)]. Correlations were related to unilateral or combined assessment of nasal passages and to symptomatic nasal obstruction or unobstructed nasal breathing. Sixteen studies with a level of evidence II-a or II-b fit the inclusion criteria and were further analysed. Almost every possible combination of correlations or lack thereof in relation to the variables included was found. However, when obstructive symptoms were present, a correlation between the patency symptoms with nasal airway resistance and minimal cross-sectional area was found more often than in the absence of symptoms. In cases of bilateral assessment a correlation was found almost as often as it was not between patency symptoms and total nasal airway resistance or combined minimal cross-sectional areas, while in the limited amount of studies in which unilateral assessment was done a correlation was found each time between patency symptoms and nasal airway resistance. The correlation between the outcomes found with rhinomanometry and acoustic rhinometry and an individual's subjective sensation of nasal patency remains uncertain. Based on this review, it seems that the chance of a correlation is greater when each nasal passage is assessed individually and when obstructive symptoms are present. There still seems to be only a limited argument for the use of rhinomanometry or acoustic rhinometry in routine rhinologic practice or for quantifying surgical results.

The effect of MK-0524, a prostaglandin D2 receptor antagonist, on prostaglandin D2-induced nasal airway obstruction in healthy volunteers

Nasal congestion in allergic rhinitis results from tissue edema and vasodilatation in the nasal mucosa. Of the mediators released by mast cells in response to allergens, prostaglandin (PG) D(2) is regarded as the most potent inducer of nasal congestion. Intranasal administration of PGD(2) reproduces the nasal blockade experienced by patients with seasonal allergic rhinitis (SAR) via its action on the PGD(2) (DP) receptor to induce nasal vasodilatation. Intranasal challenge with PGD(2) can be a useful tool for evaluating DP-receptor antagonists. The main purpose of this study was to examine the ability of MK-0524, a DP receptor antagonist in development for the treatment of SAR, to block PGD(2) induced nasal congestion in healthy volunteers. To this end, a double-blind, placebo-controlled, randomized, 3-period study was performed in 15 healthy subjects. During each period, subjects received MK-0524 25 mg, MK-0524 100 mg or placebo qd for 3 days. Twenty-four hours following the last dose, nasal provocations with PGD(2) were performed to determine the PD(75), which is the intranasal dose of PGD(2) that provokes a 75% increase in baseline total nasal airway resistance as performed by active anterior rhinomanometry. Following treatment with MK-0524, the PD(75) (mean+/-SD) was significantly shifted from 15.8 +/- 18.3 mug/nostril during the placebo period to more than 512 mug/nostril both following the 25- and 100-mg (maximum challenge dose tested) dose regimen. Whether this >45 fold increase in PD(75) will induce a clinically meaningful effect of MK-0524 will require clinical study in participants with SAR.