Abstract

The laryngeal mask airway (LMA) is an alternative to endotracheal intubation used in human medicine as a means of airway control.^1,2 This study compared use of the laryngeal mask airway with endotracheal intubation in western lowland gorillas (Gorilla gorilla gorilla) under general anesthesia. Seven adult gorillas, five females and two males ranging in age from five to 23 years, were included in this study. Gorillas were immobilized for routine examination with tiletamine/zolazepam (Telazol, Fort Dodge Animal Health, Fort Dodge, IA) given intramuscularly via hand injection or remote injection at doses between 3.16–4.36 mg/kg. Three gorillas were intubated, and four gorillas were fitted with a laryngeal mask airway (Ambu AuraOnce, single use laryngeal mask, Ambu A/S, Denmark). Sevoflurane (Petrem, Minrad Inc., Bethlehem, PA) was used for anesthetic maintenance, 1–7% to effect delivered in 100% oxygen via rebreathing circuit. Parameters measured and compared between the two groups included time of airway device placement, pulse oximeter oxygen saturation (SpO₂), end-tidal carbon dioxide (EtCO₂), heart rate, respiratory rate, arterial blood pH, pO₂, and pCO₂. There were no statistically significant differences in time of airway device placement, heart rate, EtCO₂, arterial blood pH, and pCO₂. The LMA group had a statistically significant greater SpO₂ 10 minutes after airway device placement, and greater pO₂ 15 and 45 minutes after placement. Respiratory rate was greater in the endotracheal intubation group at several time points. The laryngeal mask airway is an effective alternative to endotracheal intubation in western lowland gorillas.

Acknowledgments

The authors would like to thank the Great Escape department at the Oklahoma City Zoo for their assistance and care of the animals in this study, Dr. Brittany Hall of the Boren Veterinary Medical Teaching Hospital, Oklahoma State University, and Dr. Jennifer Kilburn of the Tulsa Zoo and Living Museum for their assistance with data collection.

Literature Cited

1.  Benumof JL. Laryngeal mask airway and the ASA difficult airway algorithm. Anesthesiology. 1996;84:686–699.

2.  Verghese C, Brimabombe JR. Survey of laryngeal mask airway usage in 11,910 patients: safety and efficacy for conventional and nonconventional usage. 1996;82:128–133.