| Possible causative factors |
Mechanism |
| Muscle relaxant usage in general anesthesia |
Loss of muscle tone may facilitate the retrograde passage of air into the parotid gland when the positive pressure intraorally is increased during induction of anesthesia or after coughing and excessive straining at the emergence from general anesthesia [3,7]. |
| Perioperative medications like atropine, succinylcholine, glycopyrrolate, and morphine |
Retention and increased viscosity of saliva can occlude the salivary ducts [8]. |
| Preoperative dehydration |
Retention and increased viscosity of saliva can occlude the salivary ducts [2]. |
| Intravenous ephedrine |
Ephedrine has a beta-stimulant effect that can cause vasodilation in the parotid gland [2]. |
| Surgical position |
Extreme head rotation in a long-standing surgical procedure can impair the proper drainage of the parotid gland [3] and can potentially cause glandular ischemia by squeezing arterial or venous vessels [5]. |
| Intratracheal manipulation |
Stimulation of parasympathetic nerves that mediate the pharyngeal reflex, which induces salivation, vasodilation, and hyperemia in the salivary gland [9]. |
