Study to assess the laryngeal and pharyngeal spread of topical local anaesthetic administered orally during general anaesthesia in children.

Richard Beringer (1) , Noami Skeahan (2) , Suzette Sheppard (3) , Philip Ragg (4) , Nick Martin (5) , Ian Mckenzie (6) , Andrew Davidson (5, 7)

1 Department of Anaesthesia
2 Department of anaesthesia
3 Anaesthesia
4 Anaesthesia
5 Department of Anaesthesia
6 Anaesthesia and Pain Management
7 Anaesthesia Research

Background: Topical local anaesthesia of the airway of anaesthetised children has many potential benefits. In our institution, lignocaine is topically instilled into the back of the mouth with the expectation that it will come into contact with the larynx. The volume and method of application varies between clinicians. There is no published evidence to support the plausibility of this technique. Aim: To determine whether this technique of instillation results in the local anaesthetic coming into contact with key laryngeal structures and whether this is influenced by volume or additional physical manoeuvres. Methods/Materials: Sixty three healthy anaesthetised children between six months and 16 years old had lignocaine stained with methylene blue poured into the back of their mouths. The volume and subsequent physical manoeuvre were determined by randomisation. A blinded observer assessed staining of the vocal cords, epiglottis, vallecula and piriform fossae by direct laryngoscopy. Airway complications were recorded. Results: Fifty three of the 63 children had complete staining of all four areas. Four children had one area unstained and all others had at least partial staining of all four structures. Nine children coughed following induction of anaesthesia. Coughing was more likely in children with incomplete staining (p=0.03), low volume lignocaine (p=0.003) and following a head lift (p=0.02). Conclusion: Oral administration of lignocaine without use of a laryngoscope frequently results in widespread coverage of key laryngeal structures and may reduce the risk of coughing.

Mots clés: Medicine

Richard Beringer, Noami Skeahan, Suzette Sheppard, Philip Ragg, Nick Martin, et al.. Study to assess the laryngeal and pharyngeal spread of topical local anaesthetic administered orally during general anaesthesia in children.. Pediatric Anesthesia, 2010, 20 (8), pp.757. ⟨10.1111/j.1460-9592.2010.03353.x⟩. ⟨hal-00560697⟩