Characteristics of nasal airflow and the effect of a nasal dilator in normal human subjects

Improvement of the aerobic performance in endurance athletes presenting nasal valve compromise with the application of an internal nasal dilator

PURPOSE

We investigated the effects of an internal nasal dilator on nasal airflow and cardio-respiratory capacity in adult endurance athletes, while performing controlled exhaustive physical exercise.

METHODS

Prospective observational study. Participants were 38 adult endurance athletes, 23 with and 15 without nasal valve compromise. Nasal patency was objectively evaluated with anterior rhinomanometry, acoustic rhinometry and peak nasal inspiratory flow (PNIF). Maximum oxygen uptake (VO2max), maximum pulmonary ventilation, time to exhaustion and total time of nasal respiration were recorded during a submaximal treadmill test. Dyspnea intensity and fatigue perception were evaluated using a labeled visual analog scale. All assessments were performed with and without the application of the internal nasal dilator.

RESULTS

All the parameters related to aerobic capacity were significantly reduced in the group of athletes with nasal valve compromise (p. <0.05 for all variables). The internal nasal dilator improved statistically significantly the nasal patency (p. <0.001), VO2max and aerobic performance and self-rating of dyspnea and fatigue (p. <0.05 for all parameters) only in athletes with nasal obstruction. PNIF correlated significantly with VO2max (rho = 0.4, p. <0.05).

CONCLUSIONS

Internal nasal dilation improves nasal patency and aerobic performance during submaximal exercise in adult endurance athletes with nasal obstruction symptoms due to nasal valve compromise.

A Comparison of Over-the-Counter Mechanical Nasal Dilators: A Systematic Review

IMPORTANCE

The internal nasal valve is the narrowest part of the nasal airway and a common site of inspiratory collapse and obstruction of nasal airflow. Over-the-counter mechanical nasal dilators are an alternative to surgical intervention that attempts to improve airflow through the internal nasal valve.

OBJECTIVE

To determine the efficacy of over-the-counter mechanical nasal dilators and classify these products by mechanism.

EVIDENCE REVIEW

A database of 33 available over-the-counter mechanical nasal dilators was generated via a PubMed search as well as an internet search via Amazon.com and Google, conducted from April 1, 2013, through December 31, 2015. Products determined to be unavailable or discontinued were excluded from the database. Of the devices examined in published literature, efficacy was based on objective measures, such as measured airflow, the cross-sectional area of the nasal valve, and changes in resistance. Measures of reported sleep quality or patient perception were excluded.

FINDINGS

An analysis of each product's mechanism revealed 4 broad classes: external nasal dilator strips, nasal stents, nasal clips, and septal stimulators. A review demonstrated 5 studies supporting the use of external nasal dilator strips, 4 studies supporting the use of nasal clips, 1 study supporting the use of nasal stents, and no studies supporting the use of septal stimulators.

CONCLUSIONS AND RELEVANCE

Our findings suggest that external nasal dilator strips and nasal clips effectively relieve obstruction of the internal nasal valve and may be an alternative to surgical intervention in some patients.

Neither internal nor external nasal dilation improves cycling 20-km time trial performance

OBJECTIVES

Research is equivocal regarding endurance performance benefits of external nasal dilators, and currently research focusing on internal nasal dilators is non-existent. Both devices are used within competitive cycling. This study examined the influence of external and internal nasal dilation on cycling economy of motion and 20-km time trial performance.

DESIGN

The study utilized a randomized, counterbalanced cross-over design.

METHODS

Fifteen trained cyclists completed three exercise sessions consisting of a 15min standardized warm up and 20-km cycling time trial while wearing either a Breathe Right^® external nasal dilator, Turbine^® internal nasal dilator or no device (control). During the warm up, heart rate, ratings of perceived exertion and dyspnea and expired gases were collected. During the time trial, heart rate, perceived exertion, and dyspnea were collected at 4-km intervals and mean 20-km power output was recorded.

RESULTS

No differences were observed for mean 20-km power output between the internal (270±45W) or external dilator (271±44W) and control (272±44W). No differences in the economy of motion were observed throughout the 15-min warm up between conditions.

CONCLUSIONS

The Turbine^® and Breathe Right^® nasal dilators are ineffective at enhancing 20-km cycling time trial performance.

Non-invasive Assessment and Symptomatic Improvement of the Obstructed Nose (NASION): a physiology-based patient-centred approach to treatment selection and outcomes assessment in nasal obstruction

OBJECTIVES

To evaluate the impact of selecting treatment for nasal obstruction on the basis of a structured physiology-based assessment protocol on patient outcomes.

DESIGN

Prospective longitudinal study.

SETTING

District general hospital.

PARTICIPANTS

A population of 71 patients with a mean age of 33 years, containing 36 males, presented with nasal obstruction for consideration of nasal surgery. All patients underwent a structured clinical assessment, skin prick allergy testing and oral-nasal flow-volume loop examination. Fifty-one patients completed the follow-up, and mean follow-up was 11 months.

MAIN OUTCOME MEASURES

NOSE, SNOT-22 and NASION scales.

RESULTS

Of the 51 patients who completed follow-up, six had conservative treatment, 28 had septal/turbinate surgery, and 17 underwent nasal valve surgery. Mean NOSE score fell from 68 ± 18 to 39 ± 31 following the treatment. Mean SNOT-22 score fell from 47 ± 20 to 29 ± 26 following the treatment. The difference between pre-treatment and post-treatment NOSE and SNOT-22 scores were statistically significant. Success rate of septal/turbinate surgery in patients without nasal allergy was 88%, and this fell to 42% in patients undergoing septal/turbinate surgery who also had nasal allergy. Presence of nasal allergy was the only independent predictor of treatment failure. Patients with nasal valve surgery reported significantly greater symptomatic improvement following surgery. The newly formed NASION scale demonstrated internal consistency with a Cronbach α of 0.9 and excellent change-responsiveness and convergent validity with correlation coefficients of 0.64 and 0.77 against treatment-related changes in SNOT-22 and NOSE scales, respectively.

CONCLUSIONS

Successful surgical outcomes can be achieved with the use of a structured history, clinical evaluation and physiological testing. Flow-volume loops can help elucidate the cause of nasal obstruction. The newly formed NASION scale is a validated retrospective single time-point patient outcome measure.

The effects of an external nasal dilator and nasal dimensions in Asians

OBJECTIVES

We examined the potential correlation between the effectiveness of an external nasal dilator for Asians and nasal dimensions.

STUDY DESIGN AND SETTINGS

The length, width, and height of the subjects' nose were measured. From these parameters, a nasal index (nasal width/nasal length) and a basal view index (columella height/nasal width) were calculated. Nasal airway resistances with and without an external nasal dilator were measured.

RESULTS

There was a significant correlation between both nasal index and basal view index and the changes in nasal resistance that resulted from wearing an external nasal dilator, whereas no significant correlation was detected between each of the 3 nasal dimensions and changes in nasal resistance.

CONCLUSIONS

Noses with a smaller nasal index or a larger basal view index receive greater benefits from the wearing of an external nasal dilator. The effects of external nasal dilators are influenced by nasal shape rather than by individual nasal dimensions in Asians.