Assessment of upper airway obstruction by measuring peak oral and nasal inspiratory flow.

OBJECTIVE: We wanted to access upper airway obstruction in patients undergoing tonsillectomy by measuring peak oral and nasal inspiratory airflow.
METHODS: We recruited study participants from a cohort of patients on the waiting list for tonsillectomy, with or without adenoidectomy, at University Hospital of Wales, Cardiff, UK. Fifty patients enrolled on phase I of the study and underwent pre-operative measurement of the rate of peak oral and nasal inspiratory flow; 25 of these patients returned after one month for phase II of the study and underwent post-operative measurement of the rate of both peak oral and nasal inspiratory flow.
RESULTS: Of the 25 participants who completed phase II of the study, 17 (68 per cent) showed an increase in post-operative peak oral inspiratory flow rate by an average of 45 per cent, while 18 (72 per cent) showed an increase in post-operative peak nasal inspiratory flow rate by an average of 22 per cent.
CONCLUSION: Both peak oral and nasal inspiratory flow rate measurements may be useful measures of oral and nasal obstruction. Further larger studies are needed to develop these measurements as screening and efficacy measures for adenotonsillectomy to relieve upper airway obstruction.