Preoxygenation and injectable anesthesia in dog: evaluation of maintenance and recovery periods of anesthesia and hemoglobin desaturation

This study was conducted to evaluate the efficacy of preoxygenation during the injectable general anesthesia in dogs and estimate the maintenance and recovery times besides measuring the time of hemoglobin desaturation following preoxygenation. Ten young healthy mix-breed dogs were selected and divided into two equal groups. They premedicated with IM administration of acepromazine. The first group received pure oxygen via face mask for 5 min just before induction of anesthesia. The other group received room air similarly. The general anesthesia was induced with IV injection of ketamine-xylazine mixture. The SpO₂ changes were recorded before and after preoxygenation in both groups. In addition, the duration of induction, maintenance, and recovery time of anesthesia, heart rate, rectal temperature, and respiratory rate were recorded before administration of acepromazine and were repeated each 5 min. There was no significant difference between groups in induction, anesthesia maintenance, and recovery periods. The opposite of the room air group, SpO₂ increased significantly in the preoxygenated group after preoxygenation. According to the analyzed results, preoxygenation had no impact on respiratory rate and heart rate. So, it is concluded that preoxygenation does not affect maintenance and recovery periods of injectable anesthesia in dogs. But significant oxygen saturation of blood after IV injection of ketamine was found as an important result of preoxygenation.