Cat Premed for Surgery thoughts invited

RE: Cat Premed for Surgery thoughts invited

Carl Bradbrook — Fri, 08 Oct 2021 10:09:33 GMT

You are right to question a protocol, especially in the face of "we have always done it this way". There is good evidence to support the use of a combination protocol for cat neutering, but as mentioned this includes the use of an opioid, methadone or buprenorphine. I would agree with your concern over the analgesia provided without an opioid, especially as the alpha-2 and ketamine will have a relatively short duration of action, and the NSAID will have a longer onset time.

A good place to start would be to look at reviewing any complications, assessing pain scores and auditing intra-operative analgesic interventions and then repeating the audit following addition of an opioid. As mentioned elsewhere in the thread, how was the remainder of anaesthesia managed- e.g. IV induction, tracheal intubation, inhalant maintenance or was medetomidine/ketamine the sole combination?

There are a number of factors potentially involved with the incidence of corneal ulceration, reduced tear production in the peri-anaesthetic period, reduced blink rate with the use of ketamine, and as mentioned use of a face mask to provide oxygen supplementation amongst others.

Carl

RE: Cat Premed for Surgery thoughts invited

Miriam Lodewyks — Fri, 08 Oct 2021 09:56:12 GMT

I can’t think of a reasonable excuse not to use an opioid, but in other countries I’ve heard they can be prohibitively expensive. Perhaps that perception is where it started and then they got stuck?
I’m sure the corneal ulceration is connected as I’ve seen a few of these too, wonder if the reduced tear-production from the Medetomidine, absent blink and then excessive airflow from using a mask instead of ET tube is the cause?

RE: Cat Premed for Surgery thoughts invited

Jill Butterworth — Thu, 07 Oct 2021 19:39:20 GMT

I can't think of a reason not to use an opioid other than the dubious one of cost. I've seen all manner of horrors when doing locums, I think people get stuck in their ways and are scared to change because 'the safest anaesthetic is the one you are used to ' etc. It sounds very likely that the corneal ulceration is related.

RE: Cat Premed for Surgery thoughts invited

Stephanie Wellings — Thu, 07 Oct 2021 19:12:38 GMT

I’m quite a fan of a triple combo ie medetomidine + ketamine + methadone, so in your scenario the methadone is basically being replaced with isofluorane, which doesn’t seem like something that theoretically would make for ‘balanced’ anaesthetic. I don’t know what the rationale behind not giving the opioid would be, as there’s surely less contraindications/risks for an opioid than either ketamine or medetomidine?

however I’ve never used a protocol like that so I would be reluctant to condemn it! Do you think they might consider doing a bit of an informal trial (for instance adding in methadone to some of them and comparing the iso used/blood pressure during GA/pain score in recovery?)