Safety and efficiency of metered dose inhaler delivery of salbutamol in the intubated rabbit.
OBJECTIVE
To determine the safety and efficiency of metered dose inhaler salbutamol delivered to the intubated rabbit.


METHODS
Prospective, comparative, five-group laboratory investigation.


METHODS
Animal laboratory, Department of Nuclear Medicine.


METHODS
A total of 30 adult, anesthetized New Zealand White rabbits.


METHODS
Three groups of rabbits underwent tracheal intubation through a tracheostomy and received 5 puffs of 99mTcO4 salbutamol delivered at the elbow connector (group 1) or via a catheter with its distal tip positioned at the midpoint (group 2) or bevel of the endotracheal tube (group 3). No intervention was provided for the rabbits in the fourth group. A fifth group underwent tracheal intubation through the mouth and received salbutamol (5 puffs) delivered at the bevel of the endotracheal tube.


METHODS
Delivery efficiency was expressed as the ratio of radioactivity emitted from lungs and trachea to the total radioactivity of the administered dose. Histopathologic injury scores were assigned to each trachea or lung specimen.


RESULTS
Delivery efficiency was 30 times greater in groups 3 and 5 (full catheter) than in group 1 (elbow). The injury scores were similar in all groups.


CONCLUSIONS
We conclude that the increased efficiency obtained by administration of metered dose inhaler salbutamol at the distal tip of endotracheal tube is not necessarily associated with increased epithelial injury.
Shorten
G
G
Department of Medicine, McMaster University, Hamilton, ON, Canada.
Dolovich
M
M
Kuang
A
A
Rhem
R
R
Gouda
B
B
Monkman
S
S
Cutz
E
E
Lerman
J
J
D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000009:adverse effects*; D000420:Albuterol / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000009:adverse effects*; D004353:Drug Evaluation, Preclinical; D007442:Intubation, Intratracheal; D007553:Isotope Labeling / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D009330:Nebulizers and Vaporizers; D011446:Prospective Studies; D011817:Rabbits; D011859:Radiography; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012449:Safety; D013670:Sodium Pertechnetate Tc 99m; D014132:Trachea / Q000000981:diagnostic imaging / Q000473:pathology; D014139:Tracheostomy
D000318:Adrenergic beta-Agonists; D001993:Bronchodilator Agents; D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m; D000420:Albuterol