Table 1.

Subset of 4 Pilot Pig Experiments That Established the Postoperative Monitoring Protocol.^a

Swine No.	Tracheostomy type	Monitoring details	Postoperative course	Necropsy result	Time of death	Cause of death
1	Size 4 HVLP	Checks every 8 hours with scheduled suctioning	Acute apneic event at 5 hours postoperatively, resolved with suctioning of blood from the trachea, CXR confirmed proper tracheostomy tube placement.	Mucus plug occluded tracheostomy tube and extended into distal trachea. Tracheitis and necrosis of tracheal mucosa.	POD 1 (20 hours)	Airway obstruction from mucus plug
2	Size 6 LVLP	Checks every 8 hours with suctioning as needed	Recovery from surgery was uneventful. No adverse events.	Mucus plug occluded distal tracheostomy tube and extended into distal trachea. Necrotic tissue noted in distal trachea.	POD 2 (42 hours)	Airway obstruction from mucus plug
3	Size 4 LVLP	Continuous monitoring; inner canula changed every 4 hours and scheduled suctioning every 8 hours	Recovery from surgery was uneventful. No adverse events.	No blood or mucus in tracheostomy. Minimal mucosal changes to the trachea.	POD 2 (48 hours)	Planned euthanasia
4	Size 4 HVLP	Continuous monitoring; inner canula changed every 4 hours, with suctioning as needed	Respiratory distress, stridor, O2 desaturation at 16 hours postoperatively. On tracheal suctioning, mucus plug expectorated with recovery of and O2 levels and resolution of stridor.	Necrotic tissue occluding the distal trachea to the carina. No mucus plug in tracheostomy tube.	POD 1 (32 hours)	Airway obstruction from necrotic tissue

Abbreviations: CXR: chest X-ray; HVLP, high volume, low pressure; LVLP, low volume, low pressure; POD, postoperative day.

^aData from these pilot pigs were not included in the study.