Validity of Acoustic Rhinometry in the Evaluation of Patients With Adenoid Hypertrophy:

Nasal Patency Measurement: State of the Art of Acoustic Rhinometry

Nasal obstruction is one of the main symptoms of different nasal pathologies. Many physiological and pathological conditions can produce nasal airflow impairment causing nasal obstruction and affecting patients' quality of life. There are different methods for the measurement of nasal obstruction, but in clinical practice the most common used are acoustic rhinometry, rhinomanometry, and peak nasal inspiratory flow. This review describes the fundamentals of acoustic rhinometry, its normal values, the different physiological and pathological conditions that can modify nasal patency, and the utility of this instrument for the measurement of nasal obstruction in clinical practice. Acoustic rhinometry is a simple test, so it is suitable for measurements in the pediatric population, i.e., for evaluating adenoid hypertrophy. Acoustic rhinometry normal values are available, unilaterally and bilaterally for pediatric and adult populations. Acoustic rhinometry has been demonstrated to be reproducible and even superior to rhinomanometry when measuring nasal modifications during challenges. It is possible to use acoustic rhinometry before and after nasal surgery. Measuring nasal cavities volume and cross-sectional area, acoustic rhinometry is particularly indicated in rhinosurgery, especially for the evaluation of spreader grafts. Brief considerations about the correlation between nasal symptoms, in particular the subjective sensation of nasal obstruction, and the acoustic rhinometry results as well as the correlation of acoustic rhinometry with other methods for the measurement of nasal obstruction are also reported. Objective and subjective evaluation of nasal obstruction gives different information that together optimizes the diagnosis and the treatment of rhinologic patients. Acoustic rhinometry alone or in combination of other instruments for the measurement of nasal obstruction or patency should be used regularly in every outpatient clinic that treats patients with nasal obstruction as there is an increasing need of evidence-based therapies.

Modified adenoid grading system for evaluating adenoid size in children: a prospective validation study

Nasal endoscopy is the best choice for evaluation of adenoid size, but very few studies published on the endoscopic quantitative assessment. This study aimed to newly propose and validate a modified adenoid grading system (MAGS) with the existing endoscopic scoring methods of adenoid size. A prospective study on children with chronic mouth breathing and having endoscopic nasal examination was conducted. Digital images obtained during endoscopic examination were evaluated with the traditional method and the MGAS. Adenoid size was also evaluated by intraoperative nasal endoscopy among those underwent adenoidectomy. One hundred and thirty patients were enrolled. The MAGS showed high inter-rater reliability with a Kappa score of 0.869. Sixty of 130 patients underwent adenoidectomy and assessed with intraoperative nasal endoscopy. The MAGS significantly correlated to the percentage of nasopharyngeal obstruction of intraoperative endoscopy (Spearman's r = 0.796, gamma coefficient = 0.94), and the percentage of choanal obstruction of preoperative endoscopy (Spearman's r = 0.816, gamma coefficient = 0.859). Our findings suggest that the MAGS has high reliability and validity for assessment of adenoid size. It may be a more suitable and reliable grading system for endoscopic evaluation of adenoid size.

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.

Pre- and post-operative application of acoustic rhinometry in children with otitis media with effusion and with or without adenoid hypertrophy-a retrospective analysis

BACKGROUND

There is no standardized scheme for preoperative evaluation of adenoid hypertrophy or a consensus on surgical indications for adenoidectomy in children with otitis media with effusion (OME), especially for young children intolerant to nasal endoscopic assessment. The aim of this study was to evaluate the efficacy and reliability of acoustic rhinometry (AR) in evaluating benefits from adenoidectomy in children with OME.

METHOD

Children with OME who were scheduled for surgical intervention were reviewed and AR tests performed preoperatively and postoperatively. The patients were divided into two groups based on the surgical strategy (Group I: tympanostomy tube placement alone; Group II: tympanostomy tube placement plus adenoidectomy). Correlation and regression analyses were performed to assess the relationship between findings of AR and nasal endoscopy. AR parameters including minimal nasal cross-sectional area (MCA), and nasopharyngeal volume (NPV), as well as scores of subjective symptoms were obtained to evaluate the utility of AR pre- and post-surgery.

RESULTS

Sixty-five children aged 4-10 years who met the inclusion criteria were included. No significant differences in gender or age distribution were observed between Group I and Group II. MCA, as well as NPV significantly decreased in Group II when compared with Group I (p = 0.000). A significant inverse correlation was observed between NPV and choanal obstruction ratio in both groups I (r = -0.625, p < 0.001) and II (r = -0.570, p < 0.001). A significant difference between preoperative and postoperative NPV and subjective symptom scores was observed in group II after adenoidectomy (p = 0.000).

CONCLUSION

AR parameters showed a good clinical correlation with findings of nasal endoscopy and thus may be useful for evaluating candidacy for surgical adenoidectomy among children with OME, especially in whom preoperative nasal endoscopic examination is not feasible. Additionally, AR can reveal the changes occurring within the nasopharyngeal passage before and after adenoidectomy.

Measurements of nasal airflow and patency: a critical review with emphasis on the use of peak nasal inspiratory flow in daily practice

Objective measures can be used to assist the clinician to diagnose and treat nasal obstruction and also to quantify nasal obstruction in research. Objective measurements of nasal obstruction are as important as objective measurements of lung function. peak nasal inspiratory flow (PNIF), acoustic rhinometry (AR) and rhinomanometry (RM), with their specific peculiarity, assess different aspects of nasal obstruction. From the studies available in the literature, it seems that these methods roughly correlate with each other and that all of them can be alternatively utilized very well in research as well as in clinical practice. This review describes the various methods that can be used to measure nasal patency, airflow and resistance, mainly peak nasal inspiratory flow, rhinomanometry and acoustic rhinometry. PNIF has been demonstrated to be reproducible and as good an indication of objective nasal patency as formal rhinomanometry and has the advantage to be cheap, simple and suitable for serial measurements and for home use even in the paediatric population. PNIF normative data are available for children, adults and elderly subjects, and the availability of unilateral PNIF normal values allows evaluation of nasal sides separately. Just as in the lower airways, objective and subjective evaluation gives different information that together optimizes the diagnosis and the treatment of our patients. We argue that PNIF should be used regularly in every outpatient clinic that treats patients with nasal obstruction.