Usefulness of rhinomanometry in the identification and treatment of patients with obstructive sleep apnoea: an algorithm for predicting the relationship between nasal resistance and continuous positive airway pressure. a retrospective study

Abstract

Objectives: We tried to assess the relationship between nasal resistance measured by rhinomanometry and the pressure used in CPAP.

Design: Retrospective medical case series review, January 2004 to December 2014.

Setting: Tertiary care academic medical centre.

Participants: Thirty-eight patients (m = 56.55 years; male = 90.5%) with CPAP settings ≤8 and 39 patients (m = 57.49 years; male = 74.9%) with pressure settings ≥12.

Main outcome measures: Study variables were BMI, neck circumference, Epworth Sleepiness Scale score, nasopharyngeal examination and computerised anterior active rhinomanometry, sitting and supine, in basal conditions and after intranasal administration of oxymetazoline (0.05%). Nocturnal polysomnography was performed to calculate the apnoea-hypopnoea index without and with CPAP to analyse the effectiveness of the treatment.

Results: BMI and resistance in supine position after vasoconstriction at 150 Pa were useful variables to predict the pressure setting that should be used. We obtained an equation to calculate the probability that a patient requires a pressure >12 cm H₂ O as a function of their BMI and total nasal airflow at 150 pascal in supine position after vasoconstriction.

Conclusions: Rhinomanometry is useful to predict the impact of structural nasal modifications on the positive pressure to support decision-making in relation to surgery.