Abstract
Background Ketamine-xylazine is a frequently used combination for anesthesia in microsurgically
operated rats and can be administered by intraperitoneal (IP) or intravenous (IV)
injection. Both methods are associated with relatively high misadministration rates.
In the present study, we want to introduce a femoral vein access that requires microsurgical
cannulation but enables a 100% administration rate.
Methods In this study, the maximal time of anesthesia was analyzed, time to response, latency
time, and the total need for anesthetic agents in IP (n = 200) and IV (n = 40) anesthesia in Wistar rats for the purpose of microvascular operations. IV injections
were achieved with an inserted microcatheter that was applied via a microsurgical
femoral vein access.
Results The time needed for the placement of the microcatheter was 5.76 ± 0.89 minutes. Maximal
time of anesthesia (IP vs. IV) was 7.02 ± 1.92 versus 21.78 ± 5.77 hours (p < 0.0001), time to response was 137.5 ± 43.91 versus 18 ± 2.18 seconds (p < 0.0001), latency time 35.53 ± 3.21 versus 27.8 ± 2.88 minutes (p < 0.0001), and total volume of anesthetic 1.42 ± 0.39 versus 2.78 ± 0.73 mL (p < 0.0001), respectively.
Conclusion IV administration using the microsurgical femoral vein access is a feasible method
with a quicker response rate and a 100% administration rate. Furthermore, it enables
longer anesthesia, for example, complex microsurgical or other experimental procedures
in the rat.
Keywords
anesthesia in rats - intravenous application - intraperitoneal application - misadministration
rate - ketamine/xylazine anesthesia
