Effect Of Aerosolized Ketamine On Airway Reactivity Of Guinea Pig

Objective: To investigate the effect of aerosolized ketamine on airway reactivity.Methods: With the method of challenging with 2% acetylcholine-0.1% histamine mixture for 1 minute, the effects of 1% ~ 5% aerosolized ketamine and inhalating 3% ketamine for 3 ~ 30min of the airway reactivity of guinea pigs were surveyed. Another guinea pigs were inhalated 5% aerosolized ketamine for 2 hours everyday. After 6 days, the middle lobes of the right lung were taken for pathologic examination. The effect of 3% and 5% aerosolized ketamine on the threshold of pain was performed in female rats with the hot-plank test. Results: 2%~5% aerosolized ketamine inhalation had an obvious effects of airway relaxing compared with 1% ketamine (P<0.05). There was no obvious difference in the airway relaxing effect among 3% aerosolized ketamine inhalation time of 5min, 10min, 15min or 30min. The pain threshold was not significantly changed after 3% or 5% aerosolized ketamine inhalation for 30 min. No marked pathological change was seen on the lung slides after 6 days 5% aerosolized ketamine inhalation. Conclusions: (1) 2%~5% aerosolized ketamine inhalation for more than 5min has an obviously preventive effect on the induced gasping of the airway. (2) Aerosolized ketamine in halation does not increase the peripheral painthreshold. (3) Aerosolized ketamine inhalation has no pathological effect on the lung and small airway.