This review aimed to explore the role of objective nasal patency measures using acoustic rhinomanometry, PNIF and rhinomanometry in supporting clinical nasal examination findings in structural nasal deformities. The body of evidence evaluating the relationship between objective nasal patency measures and clinical nasal examination in the literature is small and limited to cohort studies. Several studies have suggested that nasal constrictions measured on acoustic rhinomanometry correlated well with anatomical nasal narrowing identified on nasal endoscopy and individuals with nasal obstruction generally had a lower minimal cross-sectional area on acoustic rhinomanometry when compared to healthy individuals.Reference Corey, Nalbone and Ng11,Reference Trindade, Conegliam, Trindade, Dias and Sampaio-Teixeira21–Reference Huang, Wang, Zhang, Dong and Yeoh23 Acoustic rhinometry is a useful screening assessment prior to septoplasty, and this may guide clinicians to select patients who may achieve high post-operative satisfaction.Reference Pirilä and Tikanto25 However, other studies suggested that acoustic rhinometry failed to provide an exact point-to-point correlation with the nasal cavity and minimal cross-sectional areas and nasal volumes are not related to nasal obstruction secondary to septal deviation.Reference Tantilipikorn, Jareoncharsri, Voraprayoon, Bunnag and Clement24,Reference Isaac, Major, Witmans, Alrajhi, Flores-Mir and Major35 Although acoustic rhinometry is useful in predicting the major sites of anatomical nasal narrowing and confirming clinical examination findings, external factors such as nasal cycle, age, posture, temperature and inter-rater variability affect objective airway testing when using acoustic rhinometry. Therefore, acoustic rhinometry may be a useful tool when used in conjunction with clinical examination findings to facilitate pre-operative planning and predicting post-operative outcomes in septoplasty. However, the use of acoustic rhinometry assessment in isolation without clinical examination may be limited by its failure to provide exact point-to-point correlation with the nasal cavity.

There is limited evidence in the literature to assess the relationship between PNIF and clinical examination findings. Current evidence suggests that the relationship between PNIF assessment and clinical examination findings is very weak.Reference Panagou, Loukides, Tsipra, Syrigou, Anastasakis and Kalogeropoulos26,Reference Rujanavej, Snidvongs, Chusakul and Aeumjaturapat33 A cutoff value of 90 L/min on PNIF was considered “normal” for patients without sinonasal disease.Reference Panagou, Loukides, Tsipra, Syrigou, Anastasakis and Kalogeropoulos26 However, this cutoff value has a high sensitivity but a low specificity when compared to anterior rhinomanometry, making clinical interpretation of PNIF values difficult in patients with nasal obstruction. The high sensitivity of PNIF may aid clinicians in identifying patients with sinonasal disease but its low specificity may result in difficulty in interpreting low PNIF values in healthy asymptomatic individuals without sinonasal disease. The bilateral nature of PNIF assessment and the fact that the nasal valve and alar collapse during rapid inspiration causing some degree of airway block make PNIF less reliable when assessing nasal blockage. The use of PNIF as a screening tool for nasal obstruction has not been widely explored and further research focusing on unilateral PNIF may be useful in the future to assess patients with varying degrees of nasal obstruction.

Rhinomanometry assessment correlates well with clinical examination findings in severe anterior septal deviation.Reference Szücs and Clement22 However, the role of rhinospirometry in assessing middle/posterior and mild/moderate septal deviation remains uncertain. Rhinomanometry assessment should be interpreted with caution as abnormally low flow rates on rhinomanometry have been previously detected in patients in patients with no septal deviation or mild deviation restricted to one anatomical area.Reference Huygen, Klaassen, de Leeuw TJ and Wentges29 Rhinomanometry is also a useful screening assessment tool prior to septoplasty to guide clinicians in selecting patients who may achieve high post-operative satisfaction.Reference Pirilä and Tikanto25,Reference Sipilä and Suonpää31,Reference Suonpää, Sipilä and Laippala32 Pirila et al. suggested that the pre-operative post-decongestant inter-cavital airflow ratio is a strong predictor for post-operative satisfaction and the optimum suggested cut of value is 1:2.Reference Pirilä and Tikanto25 The sensitivity and specificity of this cutoff value were 65 per cent and 60 per cent respectively for patients reporting high and very high post-operative satisfaction when compared to the sensitivity/specificity of anterior rhinoscopy (55%/55%). Although the sensitivity/specificity of this measurement is higher when compared to anterior rhinoscopy, the results should be interpreted with caution given the difference in sensitivity and specificity between rhinomanometry measurement and anterior rhinoscopy in assessing post-operative satisfaction is marginal.

The relationship between clinical examination findings and rhinospirometry also remains inconclusive. Nasal partitioning ratio measured from rhinospirometry is highly predictive of severe septal deviation. Although clinicians were able to differentiate severe septal deviation from moderate/mild deviation on clinical examination easily, differentiating less severe deviation from severe remains a challenge for clinicians. The sensitivity of clinical assessment of septal deviation is high but its specificity is low when compared to nasal partitioning ratio assessment in rhinospirometry. Although clinicians are able to identify severe septal deviations with NPR outside the normal range, the ability of clinicians to confidently differentiate less severe septal deviation from normal and abnormal NPR remains poor. Hence, nasal partitioning ratio assessment in rhinospirometry may be useful in assessing less severe septal deviation when used in conjunction with clinical examination findings.Reference Fyrmpas, Kyrmizakis, Vital and Constantinidis19,Reference Boyce and Eccles34

• The role of objective nasal patency measures (ONPM) in assessing structural nasal obstruction remains uncertain.

• Studies exploring the relationship between ONPM and clinical nasal examination findings are limited and confined to cohort studies in the literature.

• Acoustic rhinometry, rhinomanometry and rhinospirometry assessment correlate positively in severe anterior septal deviation but their role in assessing middle/posterior and mild/moderate septal deviation in isolation remains uncertain.

• ONPM supports clinical examination findings in severe structural nasal obstruction. Using ONPM alongside clinical examination findings may aid patient selection for septoplasty and predict post-operative satisfaction.