Gentle tissue handling, hemostasis, and opening of the airway lumen should be the operative goals, but postoperative monitoring is equally critical. The endotracheal tube should be left in place as long as the patient will tolerate it. Administering additional sedative or analgesic drugs may help facilitate a smooth extubation experience. The dog should be positioned in sternal recumbency with the tongue pulled rostrally; one-on-one care with a trained team member will help identify potential problems early. Monitoring with a pulse oximeter (placed on the tongue, lip, ear, toe web, or rectum) before and immediately after extubation is ideal. A reading of less than 90% to 94% dictates the need for supplemental oxygen. Nasal cannulation or flow-by can be used for oxygen delivery during the recovery period. An oxygen cage should be reserved for fully awake patients.
Following extubation, the dog should be monitored for signs of dyspnea, such as increased respiratory rate and effort, or progressive stridor. Body temperature should be monitored frequently because inadequate thermoregulation leading to hyperthermia could signal postoperative airway obstruction. A cold compress held on the ventral neck may help reduce laryngeal swelling. Respiratory rate and effort should be monitored every hour for the first 12 to 24 hours.
Early intervention is key to decreasing mortality risk in dogs that develop dyspnea. Signs of impending respiratory crisis include severe inspiratory effort, agitation, rising body temperature, exaggerated open-mouth breathing, and cyanosis following an episode of vomiting or regurgitation. With airway obstruction, supplemental oxygen should be applied in conjunction with sedation. Worsening of breathing character, increased breathing effort, or cyanosis warrants immediate airway re-evaluation.
If no improvement is seen within 10–20 minutes or if the condition worsens, then anesthesia induction and re-intubation should be considered. If laryngeal swelling is present after reintubation, the dog can be maintained intubated with heavy sedation or light anesthesia (eg, propofol CRI for 6–12 hours) before re-attempting tube removal. If there is concern that aspiration has occurred, thoracic radiographs should be obtained and mechanical ventilation considered.
In some cases, severe pharyngeal/laryngeal swelling necessitates an alternative airflow pathway in the form of a temporary tracheostomy. Although a tracheostomy tube requires intense monitoring and care, the procedure does not appear to contribute to mortality. Postoperative tracheostomies were performed in 0.02%–6.8% of patients in published studies without affecting survival.9–11 In only one of these studies did the severity of preoperative signs correlate with the need for postoperative tracheostomy.11 Ideally, tracheostomy should be performed in a controlled fashion with an endotracheal tube in place. Emergency tracheostomy can also be performed in acute dyspnea situations in which upper airway swelling precludes orotracheal intubation.
Antiemetics should be considered in brachycephalic dogs (metoclopramide 1 mg/kg/day IV, famotidine 1 mg/kg IV, maropitant 1 mg/kg SC). Most have pre-existing GI disease that requires treatment in addition to minimizing the danger of aspiration pneumonia. Subcutaneous pure mu-opioids for postoperative pain should be used with caution to minimize the risk for nausea that often accompanies the use of these medications (ie, administering a low dose IV to avoid the nausea and vomiting noted with slow peripheral absorption). Feeding can be started 12 to 24 hours after surgery with small meatballs fed by hand. A harness instead of a collar should be used during walking to avoid compression of the trachea.