A comparison of the v-gel® supraglottic airway device and non-cuffed endotracheal tube in the time to first capnograph trace during anaesthetic induction in rabbits

Ideally all rabbits undergoing an anaesthetic procedure should be intubated. Visualising the larynx in rabbits is difficult, therefore intubation using an endotracheal tube (ETT) requires a careful technique and is often abandoned to avoid laryngeal trauma. Masking rabbits is unreliable as they can hold their breath at the smell of isoflurane and sevoflurane (Eatwell, 2011).

Phaneuf et al (2006) studied tracheal injury after endotracheal intubation in rabbits. Looking at a total of 26 rabbits, the study found that rabbits that had prolonged intubation, slight movement of the tube during repositioning or ventilation, and repeated intubation showed marked tracheal injury on histology. They also noted that many cases of tracheal damage go unreported with the potential for post-operative mucosal necrosis and death due to respiratory obstruction.

Achieving a patent airway quickly with no trauma to the patient, and the ability to perform intermittent positive pressure ventilation (IPPV) with minimal isoflurane waste emission, is important for successful anaesthesia (Crotaz, 2013). Laryngeal Mask Airways (LMA), a type of supraglottic airway device (SGAD), are a suitable alternative for gas delivery in rabbits, but there is significant waste of anaesthetic gas (Smith et al, 2004). Nasal intubation is another alternative, especially in small rabbits where orotracheal intubation is even harder. Both Varga (2014) and Eatwell (2011) advise this should not be used in preference to oral intubation as it has the added risk of introducing pathogens into the trachea and subsequently the lung (Varga, 2014).