pain and nutrition in the perioperative period. The patient was cooperative, gentle-natured and seemingly unaffected by her trauma.
Although the left globe was evidently injured by the incident, appropriate vision was confirmed and the patient was generally in good health and willing to mobilise. She did not appear to be head shy, but due to the location of her injuries the patient was restricted to short harness walks only to maintain handling tolerance and reduce the risk of increasing intracranial pressure around the fractures.
It is important to consider that some patients may not be suitable for the intensity of treatment received in this case due to their temperament or differences in the injuries they have sustained making increases in intracranial pressure a more significant risk.
Airway management
Due to the nature and origin of the facial injuries, this patient ' s airway was considered at risk of swelling and displacement. Therefore, perioperative considerations and precautions were of particular importance. Brock and Kruse-Elliott [ 2 ] note the unsuitability of mask-based induction in cases of facial fractures due to oral discomfort. Both Soukup and Snyder [ 3 ] and Badjate et al. [ 4 ] note that there are situations, particularly in the fixation of maxillofacial fractures, where airway management is required to bypass the dentition in order to achieve intraoperative control of occlusion. This allows the surgeon to work at the fracture site without interruption, while the airway is still adequately maintained to avoid hypoxia and aid anaesthesia.
It is important to use a flexometallic endotracheal tube for alternative intubation to avoid kinking the tube at any point [ 4 ]. There are multiple methods by which a patient can be intubated to avoid the dentition, although these vary among species. Due to the anatomical impossibility of nasotracheal intubation in dogs [ 3 ], the alternative routes are tracheostomy, transmylohyoid orotracheal or pharyngotomy intubation. In the case of caudal mandibular fractures, Soukup and Snyder [ 3 ] found pharyngotomy to be a more appropriate method of intubation; however, due to the rostral fractures present in this case, transmylohyoid orotracheal intubation was selected and achieved with the endotracheal tube passing through the mylohyoideus muscle and lingual mucosa at the level of the first mandibular molar.
Transmylohyoid orotracheal intubation has been associated with lower rates of iatrogenic complications than pharyngotomy intubation [ 3, 5 ] and, when performed by a surgeon experienced in the technique, has been found to be a faster procedure. However, Badjate et al. [ 4 ] found that transmylohyoid orotracheal intubation is inappropriate for prolonged periods of assisted ventilation, so it would have been reasonable to consider alternative intubation methods or conversion back to standard orotracheal intubation in this patient, considering the extensive anaesthetic duration of 7 hours 30 min.
When using alternative methods of intubation such as transmylohyoid, pharyngotomy or tracheostomy techniques, it is important to consider the implications, both perioperatively and postoperatively, for the patient. Perioperative implications mainly involve the risk of blockage or dislodgement of the endotracheal tube, although this risk is considered lower than with other alternative intubation methods [ 6 ]. Transmylohyoid orotracheal intubation can be considered the least invasive of these alternative methods as, although the patient is left with another incision site, which must be monitored for signs of infection and breakdown, there are fewer complications associated with this method compared with temporary tracheostomy [ 7 ]. Although not reported in veterinary patients [ 6 ], signs of infection associated with transmylohyoid orotracheal intubation in humans include skin irritation, bleeding, salivary fistulas and formation of abscesses on the floor of the mouth [ 8 ]. The incidence of infection and other complications after transmylohyoid orotracheal intubation is considered low [ 4, 9 ].
Maintaining normothermia
Ospina-Argüelles et al. [ 10 ] found perioperative hypothermia to be one of the main surgical complications in canine patients, with 88 % of patients experiencing some degree of hypothermia postoperatively. Cisneros and Díaz [ 11 ] found incorrect thermal management to have a detrimental effect on recovery from anaesthesia and concluded that combining active and passive warming methods is an effective way of minimising the risk of hypothermia.
The warming mechanisms used in this case were a heat mat and a forced warm air blanket( Bair Hugger, 3M), and blankets and bubble wrap placed around the extremities. Despite the length of the fracture repair procedure, this patient maintained her body temperature well under anaesthesia, with preoperative and final temperatures of 37.8 ° C and 37.9 ° C, respectively. This could have been due to the use of appropriate active and passive warming methods, or the presence of systemic infection.
In future cases, if aware the surgical procedure would be lengthy, it would be important to use support mechanisms such as those suggested by Brock and Kruse-Elliott [ 2 ]; however a staged dental procedure could also be considered. With prolonged maxillofacial surgeries, staging may not be possible, but the preemptive use of warming mechanisms is strongly advised to reduce the risk of perioperative hypothermia.
38 Veterinary Nursing Journal