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

Authors

  • Iris Wiederstein Dr. med. vet.,

    1. Clinic of Anaesthesiology and Perioperative Intensive Care, Department of Companion Animals and Horses, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna, Austria
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  • Yves PS Moens Dr. med. vet., PhD, Diplomate ECVAA

    1. Clinic of Anaesthesiology and Perioperative Intensive Care, Department of Companion Animals and Horses, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna, Austria
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Iris Wiederstein, Clinic of Anaesthesiology and Perioperative Intensive Care, Department of Companion Animals and Horses, University of Veterinary Medicine Vienna, Veterinärplatz 1, A – 1210 Vienna, Austria. E-mail: iris.wiederstein@vu-wien.ac.at

Abstract

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 μg 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 H2O 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 cmH2O. 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.

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