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.