Guidelines and criteria for the placement of laryngeal mask airways in dogs.

OBJECTIVE: To evaluate the criteria for the insertion and correct placement of the laryngeal mask airway (LMA) in dogs. Study design Prospective descriptive clinical study. Animals Thirty healthy dogs (ASA I or II) of different breeds, age 0.33-7.0 years (2.8 +/- 2.1; mean +/- SD), weight 2.2-59.0 kg (23.9 +/- 14.4), anaesthetized for elective surgery.

MATERIALS AND METHODS: The dogs were sedated with intravenous (IV) medetomidine (10 microg kg(-1)) and butorphanol (0.2 mg kg(-1)). If considered necessary, IV propofol (1 mg kg(-1) over 30 seconds) was administered until the LMA was inserted and positioned correctly. The position of the LMA was evaluated using predefined criteria for its insertion and inflation of the cuff, together with the ability to ventilate the dogs through the LMA.

RESULTS: The criteria for insertion, inflation and ventilation which indicated a clinically optimal position of the LMA and its seal around the larynx were met in 19 dogs (63.3%). The dogs could be manually ventilated with inspiratory peak pressures of 10 cm H(2)O without capnographic or audible evidence of leakage. In 11 dogs (36.7%), the LMA was positioned suboptimally with leakage during manual ventilation with inspiratory peak pressures not exceeding 10 cmH(2)O. There was no evidence of breed-related differences in LMA placement and position.

CONCLUSIONS AND CLINICAL RELEVANCE: The technique for the insertion of the LMA using predefined criteria to evaluate a correct positioning and a seal led to a successful placement in dogs of both brachycephalic and nonbrachycephalic breeds. The LMA, in most of the dogs, was easily placed, well tolerated and offered a useful less invasive means of securing the upper airway.