Hello there! In this video, we show you the intrathecal anaesthesia in red-eared slider (Trachemys scripta elegans). This procedure has been used for surgery in tail, cloaca, rectum and hind limbs in turtles.
Spinal anaesthesia in reptiles is a bit different from mammalian because the reptilian spinal cord has no subarachnoid space. Thus, they have two meninges: the outer membrane is the dura mater and the inner membrane the leptomeninx, and cerebrospinal fluid flows between them. So, it is correct to say intrathecal anaesthesia rather than epidural anaesthesia in reptiles.
The spinal cord of reptiles extends to the tail's tip, and they do not have a cauda equina. Furthermore, in many reptilian species, the spinal cord only fills a portion of the spinal canal, with as much as 50% of the canal available in some species.
To perform this technique, we have to puncture any intervertebral space after asepsis. The size needle and syringe should be selected according to the animal’s size. We have used to use 28G ½ inch needle in 1mL syringe. After perforation, we advance the needle into the spinal canal at 30-45o angle. Sometimes we can see cerebrospinal fluid comes up to the syringe. That’s fine. Some blood may come up as well. If an excessive amount of blood is aspirated, the needle should be repositioned until no further blood is aspirated. We must inject anaesthetic solution after 15-20 seconds.
The local anaesthetic drugs recommended are the same as in mammals. We can define drug volume based on the animal’s length, being 0,1mL to 5cm of carapace length (0,05mL to 1 inch), producing a motor block of the tail and cloaca, or 0,2mL to 5cm of carapace length (0,1mL to 1 inch), producing motor block either to the hind limbs. This technique is a bit the same as performed in lizards, which we can check in this other post..
About drug doses, we can use lidocaine (2 - 4 mg/kg) which promotes motor block for about one hour, or bupivacaine (1 mg/kg), lasted about 2 – 3 hours.
To watch other procedures, go to this link!
– Fontenelle JH et al. Anestesia epidural em jabuti piranga (Geochelone carbonaria). Encontro da ABRAVAS, 2000, p 7.
– Mans C. Clinical technique: Intrathecal drug administration in turtles and tortoises. J Exotic Pet Med, 23:67-70, 2014.
– Rivera S. Intrathecal anesthesia in reptiles: Who knew… NAVC Conference 2013.
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