Physiologic and pathologic septal deviations: subjective and objective functional rhinologic findings

Abstract

OBJECTIVE: A high incidence of septal deviation with significant inter-rater variability has been reported. An explanation could be the presence of physiological septal deviation besides pathological ones. We differentiated an unselected cohort by their nasal resistance into groups with physiological normal and pathologically increased resistance to detect differences and analogies in comparison to healthy subjects and a pathological cohort. STUDY DESIGN: Prospective cohort study. SETTING: A total of 356 patients were assessed using rhinoresistometry, acoustic rhinometry, endoscopy and visual analogue scales. After definition of a benchmark between physiological and pathological nasal resistance, group differences were calculated and correlations analysed. RESULTS: The normal one-sided inspiratory nasal resistance was defined as less or equal to 0.35 sPa/cm^3 at a flow-velocity of 250 cm^3/s (R250). Using this benchmark, the unselected group of non-rhinological patients was differentiated into 114 subjects with physiological nasal resistance and 44 with pathological septal deviation. Nasal resistance after decongestion was significantly lower for normal or patients with a physiological septal deviation in comparison to the rhinological one on both nasal sides. Healthy subjects and patients with physiological septal deviation showed similarities in objective rhinological parameters as well as rhinological patients and patients with pathological septal deviation derived from the unselected group of non-rhinological patients. Furthermore, this benchmark of nasal resistance shows significant correlations with subjective assessment of nasal breathing. CONCLUSION: Inspiratory nasal resistance obtained at a flow-velocity of 250 cm^3/s using rhinoresistometry may be useful to distinguish patients with physiological and pathological septal deviation. Correlation with subjective assessment and endoscopic findings is improved.