RHINOMANOMETRY / ACOUSTIC RHINOMETRY – ROLE IN NASAL OBSTRUCTION BY- DR. SUPREET SINGH NAYYAR, AFMC FOR MORE PRESENTATIONS, VISIT 7/20/

BACKGROUND Complaint of a blocked nose Complex clinical problem Frequently difficult to assess The perception of nasal airflow - subjective Efforts to improve our ability to ‘objectively’ measure nasal patency Gold standard would be a quantifiable, reproducible, objective test with a strong correlation to the subjective perception of nasal airflow Various methods 7/20/

Rhinomanometry provides a functional measure of the nasal airway resistance or conductance Acoustic rhinometry provides an anatomical measurement of cross-sectional area or nasal volume 7/20/

RHINOMANOMETRY Dynamic test of nasal function that calculates nasal airway resistance (NAR) Measures Transnasal pressure Nasal airflow Flow-pressure curves Laminar airflow versus turbulent airflow Three methods Active anterior rhinomanometry Passive anterior rhinomanometry Active posterior rhinomanometry 7/20/

RHINOMANOMETRY 7/20/

UNILATERAL NASAL AIRFLOW Measured at sample pressure point of 150 Pa and bilateral nasal airflow measured at 75 Pa are recommended as universal standards However, Asian population cannot always achieve these pressures during normal quiet breathing and the lower sample pressures of 100 and 50 Pa, respectively, are generally accepted for nasal resistance measurements in Japan. Total nasal resistance to airflow can be either determined directly using the posterior method of rhino manometry or it can be calculated by combining the two separate values of nasal resistance for the two nasal passages as shown in the formula below: 1/R (total) = 1/r (left)+1/r (right) The reciprocal of total resistance is equal to the sum of the reciprocals of left and right resistance. 7/20/

ACOUSTIC RHINOMETRY Based on the analysis of sound waves reflected from the nasal cavity Two -dimensional picture of the nasal cavity Can identify the narrowest part of the nasal cavity or minimal cross-sectional area (MCA) Usually corresponds to the nasal valve area 7/20/

ACOUSTIC RHINOMETRY 7/20/

OTHER METHODS Peak nasal inspiratory flow rate Body plethysmograhy Nasalance Measured by pair of directional microphones mounted on either side of hard palate Ratio of nasality of sound output from nose vs mouth Inversely proportional to nasal airway resistance Normal 40% Rhinostereometry Plotting of changes of inf turbinate by binocular microscope Patient head fixed by biting into tailor made tooth splint fixed on microscope 7/20/

SUBJECTIVE ASSESSMENT ‘NOSE’ SCALE* Symptoms over past one month 7/20/ Nasal Congestion Nasal Blockage Breathing Difficulty Trouble sleeping Unable to get air during exercise Not a problem Very mild problem Mod problem Fairly bad problem Severe problem } Nasal Obstruction Symptom Evaluation Scale *Nose Scale 2003 The American Academy of Otolaryngology and Head & Neck Foundation.

Another subjective SNOT 22 (Sino Nasal Outcome Test) 7/20/

FACTORS AFFECTING RESULTS Vasoconstrictors Drugs Surgery Nasal Cycle 7/20/

Nasal challenge test This test provides precise measurements of changes in nasal airway resistance along with observations such as number of sneezes and measurement of inflammatory mediators in the nasal secretions after exposure to an allergen. The more commonly known "sniff test," uses a visual assessment of mucosal swelling and rhinorrhea after a small amount of dry pollen is inhaled. 7/20/

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