Piloting a novel porcine model for endolaryngeal injury following prolonged intubation.
OBJECTIVE
(1) To develop a practical animal model of endolaryngeal damage secondary to prolonged endotracheal intubation. (2) To demonstrate the contribution of chronic hypoxia to laryngeal injury in the context of this model.


METHODS
Four Sus scrofa piglets were anaesthetized and intubated for 24h. Two animals were maintained in a state of constant hypoxia (pO(2)<60 mmHg) while two others were ventilated with 100% oxygen. Prior to sacrifice, fluorescein dye was infused intravenously to highlight areas of hypoperfusion. The larynx and trachea were then harvested for gross and histological examination.


RESULTS
All four specimens demonstrated areas of edema, erythema, and ulceration on gross examination. Areas of significant histological inflammation, ulceration, and necrosis involved tube-mucosa contact, in particular, the arytenoids, the interarytenoid area, and the subglottis.


CONCLUSIONS
This animal model represents a practical and novel means for the investigation and treatment of laryngeal injury secondary to prolonged endotracheal intubation. Significant injury to the endolarynx was evident after only 24h of intubation and the injury involved similar areas within the larynx as described in human studies. Although clinical experience suggests that chronic hypoxia is a risk factor for endolaryngeal injury, this model did not provide experimental evidence to support this observation, most likely due to the small study size.
Shah
Manish D
MD
Department of Otolaryngology Head & Neck Surgery, The Hospital for Sick Children, 555 University Avenue, The University of Toronto, Toronto, Ontario, Canada M5G 1X8.
Nguyen
Lily H P
LH
Campisi
Paolo
P
James
Adrian
A
Taylor
Glenn P
GP
Forte
Vito
V
D000818:Animals; D000860:Hypoxia / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D007820:Laryngeal Mucosa / Q000098:blood supply / Q000378:metabolism; D007830:Larynx / Q000293:injuries* / Q000503:physiopathology; D008297:Male; D010100:Oxygen / Q000378:metabolism; D010865:Pilot Projects; D013552:Swine; D013997:Time Factors; D014947:Wounds and Injuries / Q000150:complications / Q000209:etiology / Q000503:physiopathology
D010100:Oxygen