The role of peak nasal and oral inspiratory flow in the evaluation of patients with sleep-related breathing disorders.

BACKGROUND: Sleep-related breathing disorders (SRBD) are common reported disorders in the adult population. The nose plays an important role in the development of SRBD; thus, the measurement of nasal respiratory function remains an important step in the management of these patients. Peak nasal inspiratory flow (PNIF) is a useful tool to assess nasal airflow and it has recently been studied together with peak oral inspiratory flow (POIF). OBJECTIVE: The aim of the present study was to evaluate the role of PNIF and POIF in an adult population of patients affected by SRBD. METHODOLOGY: Seventy consecutive adult patients with SRBD were included in the present study. All patients were evaluated with home-based sleep studies (type III), PNIF, POIF, SNOT-22 questionnaire, Epworth Sleepiness Scale test and VAS for nasal obstruction. RESULTS: Although PNIF and POIF showed to correlate with each other, no correlations were observed between Apnea Hypopnea index (AHI) and PNIF, POIF or NPI (PNIF/POIF). A further analysis showed a marginal correlation between SNOT- 22 and AHI and between SNOT-22 and POIF. Furthermore, in a multivariate analysis, also POIF marginally correlated with some of the sleep- related SNOT-22 items. CONCLUSIONS: In the present study neither PNIF nor POIF were found to be associated with OSAS severity. However, POIF values correlated better than PNIF with sleep related symptoms suggesting that POIF could be a more useful parameter for upper airway assessment in patients with SRBD. In addition, a correlation between OSAS severity, in terms of AHI, and SNOT-22 total score has been reported.

Comparison between unilateral PNIF and rhinomanometry in the evaluation of nasal cycle.

BACKGROUND: Human unilateral nasal airflow shows spontaneous changes over a period of hours due to the alternating congestion and decongestion of the venous sinuses within the nasal turbinates and nasal septum. The aim of the present study was to compare PNIF and unilateral PNIF with nasal resistances measured by means of AAR in the evaluation of the nasal cycle. METHODS: PNIF, unilateral PNIF and AAR measurements were randomly performed in 20 non-smokers, non-asthmatic volunteers, with a SNOT 22 score lower than 1. Nasal measurements were done four times in a single day at 08.30, 11.00, 13.30 and 16.00. The correlation between PNIF, unilateral PNIF and nasal resistances was studied. The pattern of nasal airflow for each subject was also analyzed. RESULTS: A significant negative correlation between PNIF-lPNIF-rPNIF and respectively AAR-lAAR-rAAR was found. Only 1 subject did not show nasal cycle, while all the rest were equally distributed between a reciprocal pattern of the nasal cycle, or an in-phase changes of the nasal cycle, both at PNIF and AAR. CONCLUSIONS: Nasal cycle can be easily assessed by means of PNIF. In fact, AAR and PNIF showed a reasonable correlation in the measurement of nasal cycle, although PNIF offered a lower variability. Reciprocal and in-phase patterns of the nasal cycle were equally distributed in our population.

Comparison between unilateral PNIF and rhinomanometry in healthy and obstructed noses.

AIMS: Peak Nasal Inspiratory Flow (PNIF) is an easy method to assess nasal patency. Normative unilateral PNIF data in adults have been proposed. The study purpose was to compare PNIF and unilateral PNIF values to total and unilateral nasal resistances measured by anterior active rhinomanometry (AAR) in subjects with and without nasal obstruction to see whether unilateral PNIFis sensitive to detect nasal obstruction. METHODS AND RESULTS: Measurements of PNIF, unilateral PNIF and AAR were performed in 125 volunteers. Seventy of them were healthy subjects not complaining of nasal symptoms and entered into the study as the'normal' group. The other group consisted of fifty-five symptomatic subjects.Data were analysed to show the correlation between PNIF, unilateral PNIF and nasal resistances. The ability of PNIF and AAR in predicting pathologies were compared by receiver operating characteristic (ROC) analysis indicating that PNIF and AAR have a similar and significant power to discriminate pathologic from healthy subjects. CONCLUSION: The measurement of unilateral PNIF could be a helpful method to support the diagnosis of nasal blockage also in those cases with single nostril obstruction, but, in cases of doubt, AAR should also be performed to improve diagnostic accuracy.