Does topical lidocaine before tracheal intubation attenuate airway responses in children? An observational audit

The use of topical lidocaine, applied to the airways with various administration techniques, is common practice in pediatric anesthesia in many institutions. However, it remains unclear whether these practices achieve their intended goal of reducing the risk of perioperative respiratory adverse events (PRAE) in children undergoing elective endotracheal intubation without neuromuscular blockade (NMB). The relative frequency of PRAE (laryngospasm, coughing, desaturation <95%) associated with no use of topical airway lidocaine (TAL), with TAL sprayed directly onto the vocal cords, and TAL administered blindly into the pharynx was assessed.

This prospective audit involved 1000 patients undergoing general anesthesia with elective endotracheal intubation without NMB. Patients with suspected difficult airways or undergoing airway surgery were excluded. The use of TAL and the mode of administration were recorded. Respiratory adverse events were recorded in the perioperative period.

Two hundred and fifty-four patients had the vocal cords sprayed under direct vision, 236 had lidocaine blindly dripped into the pharynx, and 510 received no TAL. The mean age and known risk factors for PRAE (asthma, recent upper respiratory tract infection (≤2 weeks), passive smoking, hayfever, past or present eczema, nocturnal dry cough) were similar among the groups. The proportion of patients with desaturation (<95%) between induction of anesthesia and discharge from the recovery room was higher in the two groups who received TAL (data combined for all patients receiving lidocaine regardless of administration method, P = 0.01) compared to those who received no TAL. No difference in the rates of laryngospasm (P = 0.13) or cough (P = 0.07) was observed among the groups. There was no difference in the rates of PRAE between the groups given TAL directly onto the vocal cords and in those whom received TAL blindly.

The incidence of desaturation was higher in patients receiving TAL compared with children who did not. This association should perhaps be considered when contemplating the use of this technique.