Does the Use of Lidocaine in Dogs and Cats Reduce Post-Operative Tracheitis?

Clinical bottom line: Examination of a human systematic review and two veterinary prospective trials suggest topical application on the glottis, and placement of lidocaine on the endotracheal tube both seem to improve sore throat and laryngeal response in animals. Choice of pre-medicants and induction agents appears to have an impact on the extent of lidocaine efficacy. Consideration should be given in allowing enough time for lidocaine placement to have effect (around 60-90 seconds). Limitations in more confident assertions of the efficacy of lidocaine being utilized to prevent tracheitis is that only the human systematic review had enough follow up time to examine the benefits of lidocaine on sore throat in intubation.

was thiopental and intubation, Group GTIO+Lido was thiopental with 10% lidocaine sprayed on the glottis, Group Gprop was propofol and intubation, Group GProp+LIdo had propofol and 10% lidocaine sprayed on the glottis.All lidocaine spraying occurred on the glottis and the intubator waited 60-90 seconds before intubating.15 days elapsed between the four procedures.All animals were previously sedated with acepromazine.
Study design: Prospective, non-blinded, controlled, crossover study Outcome studied: Respiratory, heart rate, pulse oximetry, number of intubation attempts, cough reflex, occurrence of laryngospasm, degree of

Clinical bottom line
Examination of a human systematic review and two veterinary prospective trials suggest topical application on the glottis, and placement of lidocaine on the endotracheal tube both seem to improve sore throat and laryngeal response in animals.Choice of pre-medicants and induction agents appears to have an impact on the extent of lidocaine efficacy.Consideration should be given in allowing enough time for lidocaine placement to have effect (around 60-90 seconds).Limitations in more confident assertions of the efficacy of lidocaine being utilized to prevent tracheitis is that only the human systematic review had enough follow up time to examine the benefits of lidocaine on sore throat in intubation.
Lidocaine spray groups worked better with thiopental but no real difference was seen between the propofol groups with lidocaine or without.

Limitations:
 No critical evaluation and lack of description of who induced and who intubated, which could have made this a blinded study. Highly subjective criteria of cough reflex without interobserver reliability. No lidocaine lubricant was placed on tube. Not enough follow-up time in post-extubation tracheitis.

Dyson (1988)
Population: 32 healthy cats scheduled for elective surgery.No additional information.

Sample size: 32 cats
Intervention details: Cats were separated into 4 groups: Group 1 Lidocaine IV.Not specified.Group 2 2% lidocaine applied to larynx, larynx was reviewed after induction.use of tuberculin syringe, with a 20g catheter that had 25g holes and the end sealed by heat.Group 3 10% lidocaine aerosol (one "squirt") to larynx, larynx was reviewed after induction.Group 4 no lidocaine.Not specified Intubation was attempted 90 seconds after groups 1-3 were given lidocaine.One clinician intubated all animals.

Study design: Prospective, non-blinded, controlled
Outcome studied: The following were evaluated by the intubating clinician: Induction consideration Amount of thiopental used for intubation Amount of thiopental used for a smooth transfer to the inhalant Laryngeal relaxation (only applied to groups 2 and 3) Intubation consideration

Response (laryngospasm) # of attempts # of coughs Tube size Extubation influence
Evidence of complications during extubation.

Main findings: (relevant to PICO question):
Less laryngospasm with topical lidocaine than IV or no treatment.Fewer efforts were made with both topical lidocaine administrations.Topical intubation allowed for larger Endotracheal tubes.

:
Didn't mention what portion of lidocaine lube administration included besides, "distal".Relevant information would include if "distal" endotracheal tube includes application on the cuff.

7 Appraisal, application and reflection
Veterinary appreciation of lidocaine's effect on post-operative sore throats is limited due to communication barriers between humans and other animals.Human research in some way provides greater advantage because patients could communicate the existence of sore throat after intubation, which occurs 30-70% of the time in Tanaka et al.'s (2015) study.Veterinary study limitations for sore throat did not have a significant follow up time, to evaluate postextubation sore throat.Future research should have better follow up periods following lidocaine application.No veterinary study examines placement of lidocaine on the endotracheal tube.Measurement of sore throat is another veterinary challenge because Visual Analogue Scales will not reliably work in determining severity of animal sore throats.Despite the limitations in the quality of human research and surrogate outcomes measured in veterinary research, lidocaine by any route does seem to improve sore throat or laryngeal response with minimal toxicity concerns.