Full text

A preliminary study was undertaken to assess the effect of commercially available external nasal splints on nasal inspiratory flow rates.

Material and Methods

Eight healthy volunteers aged 18 to 50 years agreed to participate in the study. None complained of significant nasal symptoms or had signs of nasal disease.

The System 2200 Pulmonary Function Lab (Sensor Medics, Rugby, England) was used for analysis. A transparent oronasal mask was used.

Peak inspiratory flow (PIF) per nasum was measured from functional residual capacity to total lung capacity. All testing was performed in the mid-afternoon and was standardized for factors known to affect nasal resistance: namely place, temperature, humidity, and posture. No patient was taking medication known to influence nasal resistance, and none had engaged in exercise immediately prior to testing.

Testing was then performed initially with and without splints at rest. Thereafter, each person underwent a brief duration of intense exercise wearing the nasal splints, and test values were obtained with and without the nasal splints immediately thereafter.

Results

Peak inspiratory flow at rest increased as a total from 13 (100%) to 15.49 (119%) with the addition of a splint. Peak inspiratory flow with exercise increased as a total from 13.02 (100%) to 21.61 (166%) with the addition of a splint (Table 1).

Discussion

The nasal valve area contributes approximately 50% of total airway resistance in the resting state.1 The levator alae nasi and nasalis muscles, by virtue of their attachment above and below the lateral crura, act to stabilize the nasal valve area against the considerable negative pressures exerted during nasal breathing in exercise but do not dilate this area.2,3

Nasal resistance decreases with exercise intensity but not duration of exercise, and therefore, we used brief intense exercise.4,5

In 1995, 160 million nasal strips were sold in the U.S.A. alone. These nasal strips contain a strip of plastic with memory that causes it to attempt to straighten. It is attached across the nasal bridge to the upper lateral cartilages by adhesive. In so doing, it pulls the cartilages apart, dilating the nasal valve area. This action is unnatural but reduces the airway resistance of this critical area.

All participants felt a definite subjective improvement in ease of nasal breathing while wearing the nasal strips.

The results at rest show an improvement in PIF from 100% to 119%. This result is comparable with the results of similar studies using an internal splint at rest when average increases of 24% and 29% were noted as measured by active posterior nasal rhinomanometry.5,6

It is recognized that nasal breathing is beneficial, as demonstrated in terms of pulmonary function tests.7 Furthermore, at rest and during light exercise, the majority of airflow is per nasum.8 The switching point from nasal to oronasal breathing with increasing exercise is governed by nasal work and perceived exertion of breathing.9 The use of nasal strips may, therefore, by altering nasal resistance, influence the level of activity at which nasal breathing changes to oronasal. This may allow more beneficial nasal breathing over a wider level of activity.

Table 1

Nasal strips do increase peak nasal inspiratory flow, particularly with exercise, but whether this reflects itself in improved athletic performance remains to be clarified.

Ongoing research is concerned with the effects of "sports nasal strips" on oxygen consumption with exercise and the benefits of applying "sports nasal strips" to patients with marked derivation of the nasal septum.