Recovery phase of horses after general anesthesia with inhalants with and without postanesthetic sedation with xylazine (Rompun (R))

The recovery phase is a crucial phase of equine anesthesia and the most dif ficult to control. Postanesthetic sedation is thought to be useful to preve nt horses from hastened recovery with a great chances of lifethreatening tr auma. In the following study 73 horses were given two different dosages of xylazine (0,1 mg/kg BW and 0,2 mg/kg BW, Rompun(R), Firma Bayer) after gene ral anesthesia with halothane. A third group was given saline solution only . In all horses recovery phase was monitored. The different groups were com pared for duration of general anesthesia depending on duration of recovery phase, numbers of attempts to arise and coordination of arising. Horses of group 1, sedated with a dosage of 0,2 mg/kg BW xylazine, showed s ignificantly less attempts to arise and coordination was significantly bett er Horses without postanesthetic sedation (group 3) or with lower xylazine dosage (0,1 mg/kg BW) showed a high correlation between duration of anesthe sia and number of attempts to arise or duration of recovery phase. In group 1 these correlations were lower. In all groups numbers of attempts to aris e were higher with longer duration of anesthesia. But the higher the postan esthetic sedation was the less numbers of attempts to arise were needed. It was also found, that the indication for surgery was also influencing the r ecovery period of horses. Horses of group 1 after painful surgeries (ovarec tomy) tried to arise faster and showed more attempts to arise than horses a fter less painful surgeries (vitrectomy). The results of this study show that higher dosages of xylazine (0,2 mg/kg B W) for postanesthetic sedation of horses lead to a quieter and better coord inated recovery phase.