Laryngeal mask airway insertion requires less propofol than endotracheal intubation in dogs.
OBJECTIVE
To compare the doses of propofol required for insertion of the laryngeal mask airway (LMA) with those for endotracheal intubation in sedated dogs.


METHODS
Randomized prospective clinical study. Animals Sixty healthy dogs aged 0.33-8.5 (3.0 +/- 2.3, mean +/- SD) years, weighing 2.2-59.0 (23.4 +/- 13.6, mean +/- SD) kg, presented for elective surgery requiring inhalation anaesthesia.


METHODS
Animals were randomly assigned to receive either a LMA or an endotracheal tube. Pre-anaesthetic medication was intravenous (IV) glycopyrrolate (0.01 mg kg(-1)) medetomidine (10 microg kg(-1)) and butorphanol (0.2 mg kg(-1)). Repeated IV propofol injections (1 mg kg(-1) in 30 seconds) were given until LMA insertion or endotracheal intubation was achieved, when the presence or absence of laryngospasm, the respiratory rate (fr) and the total dose of propofol used were recorded.


RESULTS
The total propofol dose (mean +/- SD) required for LMA insertion (0.53 +/- 0.51 mg kg(-1)) was significantly lower than for endotracheal intubation (1.43 +/- 0.57 mg kg(-1)). The LMA could be inserted without propofol in 47% of dogs; the remainder needed a single 1 mg kg(-1) bolus (n = 30). Endotracheal intubation was possible without propofol in 3.3% of the dogs, 47% needed one bolus and 50% required two injections (n = 30). The f(r) (mean +/- SD) was 18 +/- 6 and 15 +/- 7 minute(-1) after LMA insertion and intubation, respectively.


CONCLUSIONS
Laryngeal mask airway insertion requires less propofol than endotracheal intubation in sedated dogs therefore propofol-induced cardiorespiratory depression is likely to be less severe. The LMA is well tolerated and offers a less invasive means of securing the upper airway.
Wiederstein
Iris
I
Department of Companion Animals and Horses, Clinic for Anaesthesiology and Perioperative Intensive Care, University of Veterinary Medicine Vienna, Vienna, Austria. iris.wiederstein@vu-wien.ac.at
Auer
Ulrike
U
Moens
Yves
Y
D000768:Anesthesia, General / Q000662:veterinary*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D000818:Animals; D004285:Dogs / Q000502:physiology* / Q000601:surgery; D005260:Female; D007275:Injections, Intravenous / Q000662:veterinary; D007442:Intubation, Intratracheal / Q000662:veterinary*; D017214:Laryngeal Masks / Q000662:veterinary; D008297:Male; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies; D016896:Treatment Outcome
D018686:Anesthetics, Intravenous; D015742:Propofol