The Effect of Lignocaine on Nasal Resistance and Nasal Sensation of Airflow

Abstract

The effect of lignocaine on nasal sensation of airflow and nasal resistance was assessed in twenty-five subjects. A randomised crossover trial was conducted with lignocaine as the active drug and saline as the placebo. Both substances were delivered to the nasal mucosa as a nasal spray. Lignocaine caused a sensation of increased nasal patency in twenty-two of the twenty-five subjects studied. Saline had no such effect. The difference between this subjective effect of the two substances was highly significant (p less than 0.001). Neither spray had any significant effect on nasal resistance to airflow assessed objectively by rhinomanometry.

The Role of Sensation in Subjective and Objective Evaluation of Nasal Patency

“…This fact that nasal anesthesia increased the sensation of nasal airflow appeared to be unexpected and paradoxical finding [1]. Eccles et al [9] found that topical anesthesia (Lignocaine) caused decrease sensation of airflow and also reported that the subjects had their nose felt more blocked as a result of the anesthetic spray.…”

“…Considerable attention has been paid to quantify the degree of nasal obstruction in term of nasal resistance to airflow [6]. The fact that nasal anesthesia had been reported to increase the sensation of nasal airflow appear to be an unexpected and paradoxical finding [1]. Camphor, eucalyptus and menthol are traditionally believed to be used in the symptomatic treatment of nasal congestion and their use extends back over 100 years.…”

“…Jones et al [1], showed local anesthesia (lignocaine) had no objective effect on nasal resistance to airflow but there was a subjective sensation of improved nasal patency following its topical application. This fact that nasal anesthesia increased the sensation of nasal airflow appeared to be unexpected and paradoxical finding [1].…”

“…Conversely, it is the sensation of airflow that is important to the patient. If stimulation of the nerve endings in the nasal cavities cause an increased sensation of airflow, it would then seem reasonable to surmise that the converse is true, that anesthesia of these nerve endings would cause a sensation of nasal obstruction [1]. Patients with atrophic rhinitis suffer from a sensation of nasal obstruction in the presence of pathologically widened nasal cavities.…”

Role of cold receptors and menthol in thirst, the drive to breathe and arousal

“…The sensation of breathing is mainly related to a cool sensation in the nose rather than sensations from the respiratory muscles or lungs, and blockade of the trigeminal nerves supplying the nose or local anaesthesia of the nasal epithelium causes a sensation of nasal obstruction (Jones et al, 1986(Jones et al, , 1987(Jones et al, , 1989.…”