Anesthesia of the Superior Laryngeal Nerves and Tartaric Acid-Induced Cough
Document Type
Article
Publication Title
Archives of Physical Medicine and Rehabilitation
Abstract
Objective: The internal branch of the superior laryngeal nerve (ibSLN) conveys impulses for the laryngeal cough reflex, which protects the laryngeal aditus and prevents the development of aspiration pneumonia. The purpose of this study was to determine the effect of bilateral anesthesia of the ibSLN on the cough reflex after inhalation of a nebulized chemoirritant solution of tartaric acid.
Design: Prospective, clinical investigation.
Setting: Outpatient.
Participants: Nine healthy volunteers.
Interventions: Bilateral injections of 2% lidocaine solution without epinephrine into the paraglottic space containing the ibSLN.
Main Outcome Measures: The tidal volume after inhalation of a nebulized 20% tartaric acid solution and forced vital capacity (FVC) were measured before and after injection. Data were analyzed using the Wilcoxon signed ranks, Mann-Whitney, and sign tests.
Results: Complete anesthesia of the ibSLN abolished the laryngeal cough reflex. Postinjection tidal volumes were significantly lower than preinjection volumes (p < .01). The decrease in tidal volumes for six subjects with complete bilateral anesthesia was significantly larger than the decrease in tidal volumes for three subjects with partial anesthesia (p < .05). FVC in both the six subjects with complete bilateral anesthesia and the three subjects with partial anesthesia did not significantly change from preinjection to postinjection. None of the subjects in this study had complications or adverse respiratory sequelae.
Conclusion: Tartaric acid-induced cough may be useful in assessing the integrity of the laryngeal cough reflex after anesthesia or in patients with neurologic injury who are at risk of developing aspiration pneumonia. It may also be useful in making the decision whether to resume oral feeding.
DOI
10.1016/S0003-9993(99)90334-9
Publication Date
12-1999
ISSN
1532-821X
Recommended Citation
Addington W, Stephens R, Goulding RE. Anesthesia of the Superior Laryngeal Nerves and Tartaric Acid-Induced Cough. Archives of Physical Medicine and Rehabilitation. 1999; 80(12). doi: 10.1016/S0003-9993(99)90334-9.
