Metered-dose inhaler salbutamol-induced tracheal epithelial lesions in intubated rabbits. Effects of the site of administration and time.
OBJECTIVE
To determine (1) whether metered-dose inhaler (MDI) salbutamol administered at the elbow connector of the anesthetic circuit produced tracheal epithelial lesions in intubated rabbits, and (2) the time course for resolution of tracheal lesions produced by MDI salbutamol through an intratracheal catheter.


METHODS
Prospective, randomized, controlled trial.


METHODS
University-affiliated animal research laboratory.


METHODS
Thirty-nine adult New Zealand white rabbits.


METHODS
(1) Twenty-one intubated rabbits received 0,5, or 20 puffs of MDI salbutamol delivered at the elbow connector of the anesthetic circuit. (2) Eighteen intubated rabbits received five puffs of MDI salbutamol through an intratracheal catheter and were killed 1 h, 24 h, or 1 week later.


METHODS
Samples of trachea, bronchi, and lungs were examined by light microscopy, and the degree of epithelial injury was assessed semiquantitatively.


RESULTS
MDI salbutamol (5 or 20 puffs) administered at the elbow did not induce tracheal epithelial injury. When administered through an intratracheal catheter, MDI salbutamol (five puffs) produced moderate or severe tracheal epithelial injury in those killed 1 h after the study. Evidence of epithelial regeneration was observed 24 h after the injury and recovery was virtually complete by 1 week.


CONCLUSIONS
Epithelial lesions do not occur when the MDI salbutamol (5 or 20 puffs) is administered at the elbow connector of the ventilation circuit. Tracheal epithelial lesions produced by MDI salbutamol (five puffs) administered through an intratracheal catheter resolve within 1 week of the injury.
D000420:Albuterol / Q000008:administration & dosage / Q000633:toxicity*; D000818:Animals; D001980:Bronchi / Q000187:drug effects / Q000473:pathology; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D005260:Female; D007442:Intubation, Intratracheal; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008297:Male; D009330:Nebulizers and Vaporizers; D011817:Rabbits; D013997:Time Factors; D014132:Trachea / Q000187:drug effects* / Q000473:pathology
D000420:Albuterol