ACOUSTIC RHINOMETRY IN THE PREOPERATIVE ASSESSMENT OF ADENOIDECTOMY CANDIDATES

Claims have been made for the potential of acoustic rhinometry (AR) in the evaluation of adenoidectomy patients. Little evidence has been pr esented to support such claims, and evidence is accumulating that AR i s inaccurate in reflecting anatomical reality in the nasopharynx. We s et out to establish whether acoustic rhinometry studies could predict operative decision-making sufficiently for it to be of assistance to t he clinician, despite these theoretical and practical obstacles. A tot al of 101 patients aged 2-13 years were examined by AR using the impul se technique. Parameters were chosen from the area-distance function t o indicate nasopharyngeal volumes and areas (decongested and non-decon gested). This information was compared with findings at EUA (examinati on under anaesthesia-obstruction categories: A-'good airway' to D-'sev ere obstruction'), operative decision (2 categories-'obstructive' = re move, versus 'non obstructive' = leave in situ) and parents' symptom s cores. Twenty-one patients were also evaluated post-operatively. There was considerable overlap between the AR parameters in the groups clas sified at EUA as 'obstructive' or 'non obstructive', but this overlap diminished after decongestion. Logistic regression demonstrated that t he decongested volume and area parameters were of significant predicti ve value with respect to operative decision (odds ratio for unit chang e in volume = 0.82; 95% C.I. = 0.70-0.97; p = 0.018). Parents' analogu e scores for snoring and for [snoring + obstruction + mouthbreathing] were also of significant predictive value. The presence of rhinitis di minishes the predictive value of AR. Acoustic rhinometry has potential as a pre-operative evaluation of the nasopharyngeal airway in adenoid ectomy candidates, but the predictive value is low unless combined wit h clinical factors.