Rabbit GA protocols

RE: Rabbit GA protocols

Thomas Johnson — Tue, 06 Nov 2018 08:56:59 GMT

[quote user="Liz Barton"]Just wondered if there's a rationale for giving a buprenorphine pre-med IM prior to placing an IV catheter and giving the medetom/ketamine induction IV? Purely from a reduction in stress during the handling process and induction? Marie and others please also give your thoughts.[/quote]

I tend to give rabbits buprenorphine 0.03mg/kg and medetomidine 0.1mg/kg (both 1ml/10kg) i/m as a pre-med, then place an i/v catheter and give ketamine i/v to effect, usually 6-10mg/kg (0.6-1ml/kg). We have V-gels and I then maintain them on iso.

RE: Rabbit GA protocols

Michael Woodhouse — Tue, 06 Nov 2018 02:17:52 GMT

[quote user="Liz Barton"]

Hi Ivan

Finding your posts really helpful, and agree about your comments on ET tube placement and use of V-gels.

[/quote]

I don't know his V-gel plug: post ration is too high for me.

Not sure whether to say this but then it's a moderator who's resurrected the old thread; some of the 'experts' in this thread must be seeing a different population of rabbits to me. I wonder what percentage of rabbits see a vet in their entire life, and then again I wonder what percentage end up intubated with IV access for 'long abdominal surgery' or CT scans. I've always found rabbit owners very reluctant clients who are very price conscious. I can't see us neutering a rabbit again if we added in all the bells and whistles mentioned in this thread (although I accept there is a tiny bunny owning population of owners wanting that). I'm happy with s/c triple and O2 by mask. Never lost one yet but don't do big numbers.

Although I approach these threads with a healthy scepticism as when we had rabbits as a child they never saw a vet and we had a couple live out in a hutch to 10+ years old. If anything they are too long lived as a child's pet.........

RE: Rabbit GA protocols

Ivan Crotaz — Mon, 05 Nov 2018 09:49:19 GMT

We tend to syringe feed if not eating within about 1-2 hours after recovery (most get an initial syringe feed), then if they are not eating by the time they go home, we get the owners in a nurse clinic, teach them how to syringe feed and get another 1-2 feeds done that evening. This would be suitable (in my opinion) for most routine procedures. If you've done something that would be expected to be painful - long abdominal procedure or dental marsupialisation then I'd keep them hospitalised.

RE: Rabbit GA protocols

Ivan Crotaz — Mon, 05 Nov 2018 09:40:45 GMT

For routine/elective cases, we try wherever possible to send home on the day of the op - I absolutely agree that they are much more likely to eat in their home environment. This works much better when there is a partner rabbit and where the housing is of good quality.

Where I get concerned is with inexperienced owners, with poor quality damp or badly insulated housing and no partner rabbit. Then you have no observation of the animal and an environment that is not going to help recovery. If they are kept inside for the initial recovery period, check what kind of environment is available. Collapsible puppy crates can be hired out for recovery periods. With some owners I'd try to keep the rabbits in for 1-2 days after surgery and certainly for more serious dental surgery, hospital care makes it much easier to give decent analgesia.

Getting a bit of information about housing pre-op is really valuable. I'd really recommend booking a routine 24hr postop check anyway - the majority of ileus or inadequate analgesia complications are quite simple to treat at that stage, but get much worse if left.

RE: Rabbit GA protocols

Ivan Crotaz — Mon, 05 Nov 2018 09:32:55 GMT

Dear Liz

Yes, I think that's a reasonable thing to do - it would have two advantages over the purely IV technique. Firstly as you say, you're going to get good sedation which is likely to reduce stress. Secondly every patient is going to get a calculated dose of buprenorphine which is not always the case when administering a dose to effect iv.

I would experiment with s/c admin - I find that I get just as good sedation and analgesia from a s/c route as an i/m route. I/M administration in an unsedated rabbit can be painful and stressful for all involved... Up to you - I rarely use the i/m route in rabbits and I can't see much of a difference in day to day work.

RE: Rabbit GA protocols

Gillian Mostyn — Sun, 04 Nov 2018 23:24:43 GMT

Most of my patients eat on recovery (especially if offered dandelions etc) but I don't keep them in if they aren't. Some are just too stressed and nervous to eat in a different environment...especially those that spend 24/7 in their wooden box with very little handling. IMO, most rabbits do much better at home. The owners are obviously told to bring them back the following morning if not.

RE: Rabbit GA protocols

Silvia Maldonado — Sun, 04 Nov 2018 21:34:27 GMT

Out of curiosity, How many of you need to keep the rabbits overnight in hospital because they are still not eating by the time they should be discharged?

RE: Rabbit GA protocols

Liz Barton — Sun, 04 Nov 2018 09:43:26 GMT

Hi Ivan

Finding your posts really helpful, and agree about your comments on ET tube placement and use of V-gels.

Just wondered if there's a rationale for giving a buprenorphine pre-med IM prior to placing an IV catheter and giving the medetom/ketamine induction IV? Purely from a reduction in stress during the handling process and induction? Marie and others please also give your thoughts.

Thanks!

RE: Rabbit GA protocols

Marie Kubiak — Sun, 15 Apr 2018 19:14:18 GMT

[quote user="David Mills"]The myth that rabbits are the same as dogs and cats and can be expected to do as well through a gamut of diagnostics and therapeutics is perpetuated by closeted exotics vets quite unaware of what is possible in general practice[/quote]

David, David, David. I am going to have to assume that you are not going to be a keen buyer of my textbook? If it helps it is heavily influenced by my years of working in practice (predominantly first opinion practice with no fancy equipment but you got me, I did see some referrals too).

[quote user="David Mills"]Why oh why do these exotics vets not publish more? [/quote]

The full time job, plentiful advice calls to colleagues, time commitments to family, allotment, cake obsession etc all take their toll. I try and publish at least two original research papers and a few review type articles each year these days but topics vary heavily depending on what I and colleagues are seeing/doing in enough numbers to make it more than a collection of anecdotes. If it makes you feel more cheerful I have published some work on the role of pre-medication in parrot anaesthesia (as well as a couple of anaesthesia/analgesia review articles for the vet press). And, just to keep you sweet, I have got a bit over-excited about vertebral heart scores in primates the last 2 years... That aside, I can see your point. It would be lovely to have large numbers of rabbits used in a trial comparing different protocols (not just drugs but other relevant factors such as intubation/temperature management etc). It isn't ethical to do anything as a single practitioner as giving one anaesthetic to one group and a different one to another purely on the basis of research is not allowed. Collecting data from two or more practitioners that are using different anaesthetics already is possible but then all kinds of variables creep in and numbers have to be huge to be meaningful. I will think and talk to those more powerful than me in the rabbit world and see if we can do something as this is a big stress for many people and I still feel it shouldn't be. If the data is collected and shows rabbits are rubbish and die whatever anyone does then I will share that and buy you a drink (as well as eating my hat). Possibly at the 2020 VetSurgeon conference that Arlo Guthrie should host...

Marie (missing the one-stars to let me know the level of disapproval reached...)

RE: Rabbit GA protocols

grumpyoldman — Fri, 13 Apr 2018 14:22:53 GMT

[quote user="Ivan Crotaz"] tend to find that lower inflation pressures (8-12cm H20) give good lung inflation and keep Co2 down to normal levels. Do you find that you get better results from the higher inflation pressures?[/quote]

Depends on the individual and what we are doing but probably wouldn't want to go lower than 14-16 . Almost every CT has some lung path and we worry about compliance and atelectasis. I think the manufacturers recommended 14. But I suspect that may have been on young SPF lab bunnies not old pets with health problems.

RE: Rabbit GA protocols

Helen Browning — Fri, 13 Apr 2018 10:06:50 GMT

Good bit of advice I had recently was that if it was an elective surgery then to have in for a pre-op appointment and discuss husbandry, if anything was below par (usually sadly diet!) then to wait and get this sorted postponing surgery for at least 2 months. Therefore it will be a hopefully in a healthier position to go for surgery. Previously I used dom, ket and torb (still do for dentals), now moving more to propofol to induce (following pre-med and cleaning out of mouth prior to induction) and maintain on iso (as practice now has v-gel, really struggle with intubating otherwise), no alfaxan as yet. Pain relief, usually in buprenorphine in pre-med and meloxicam post op and repeated as nec, fluids s/c or IV. Recovery (if possible) with companion, usually prokinetics but may rethink regular use after this thread.

RE: Rabbit GA protocols

Ivan Crotaz — Fri, 13 Apr 2018 09:26:25 GMT

I tend to find that lower inflation pressures (8-12cm H20) give good lung inflation and keep Co2 down to normal levels. Do you find that you get better results from the higher inflation pressures?

RE: Rabbit GA protocols

grumpyoldman — Thu, 12 Apr 2018 22:25:07 GMT

If your doing lots of them its probably worth investing in and learning how to use an SAV04 ventilator on pressure cycling mode at 16 -20 depending upon lung compliance. because the biggest problem is sub clinical respiratory disease.

premeds midazolam 1mg/kg with torbugesic 0.05 mg /kg lidocaine 1mg/kg and alfaxan at 1mg /kg . ketamine 1mg/kg induce with more alfaxan 1mg/kg and intubate or v-gel maintain on 2% sevo with a CRI dosing the same premed every 60 mins while ventilating, Depends whether your trying to do a good rabbit GA or a cheap one. Most of the death investigations have involved apnoea from alpha 2 drugs and poor ventilation perfusion mismatch issues at the point of induction.

RE: Rabbit GA protocols

David Mills — Thu, 12 Apr 2018 19:45:15 GMT

[quote user="Marie Kubiak"]The myth that rabbits are terrible patients is perpetuated by vets assuming they are lost causes and persuading owners not to pursue treatment/diagnostics until they are moribund (and then they are likely to die!) [/quote]

The myth that rabbits are the same as dogs and cats and can be expected to do as well through a gamut of diagnostics and therapeutics is perpetuated by closeted exotics vets quite unaware of what is possible in general practice, to the extent that their pronunciations not only grate but also distance themselves from the people they are trying to educate or help.

The problem is this. Rabbits, exotics aren't terrible patients, and no one has said they are. That is hubris and a little embarrassing. They are more challenging. They are not treated as inferior by the great unwashed but there are limits to the level of care GPs can provide. To somehow suggest they aren't, and it is the GP vets fault, is completely unhelpful and quite offensive.

I congratulate you on your success rates with these patients. But that is your job. Same as if someone sent me a tricky heart or ortho case, it's my job to sort these out as this is where my relative expertise lie. If you were posting death rates at or above 1pc that would be worrying.

[quote user="Marie Kubiak"]For routine procedures in young animals, accepting regular deaths and not reacting to improve the situation is a poor standard of care.[/quote]

Again, a little embarrassing. The op has had recent deaths. One assumes the protocol has been in place for a while so a longer look at this - say a year, 2, whatever, is in order, along with a look at the particulars of the deaths. To make knee jerk assumptions is easy and self congratulatory, but it is a strawman logic of which is seen in our profession and we should be ashamed of.

Go and look at the history of the dangerous dogs act for an example of this kind of reasoning.

[quote user="Marie Kubiak"]There are many papers comparing rabbit anaesthesia protocols (and CRI analgesia) available, [/quote]

There aren't that many, and most of them are flawed. Why oh why do these exotics vets not publish more?

RE: Rabbit GA protocols

David Mills — Thu, 12 Apr 2018 19:30:28 GMT

[quote user="Emily Rainbow"]

[quote user="David Mills"]

[quote user="Ivan Crotaz"]Medetomidine is perhaps not the ideal drug for patients with renal/cardiac/circulatory issues; use the same thinking on drug choices as you would for dogs and cats.[/quote]

Medetomidine is one of the best drugs to use where there are renal and, to an extent, cardio, issues.

[/quote]

I watched a feline anaesthesia webinar on The Webinar Vet a few weeks ago who said that medetomidine reduces renal perfusion so avoid in renal cats?

[/quote]

It doesn't. Unless some new ground breaking study has been published in the last six months, then the speaker was simply perpetuating the flawed logic behind both academic and in practice teaching around alpha 2s. I include many anaesthesia specialists in this bracket.

RE: Rabbit GA protocols

Martin Atkinson — Thu, 12 Apr 2018 16:28:16 GMT

[quote user="Jimbob"]Do you tend to place an ET tube by blind intubation?[/quote]I know this question was aimed at Marie but I use blind intubation because I'm useless with a laryngoscope. So at risk of teaching granny to suck eggs: rabbit placed in sternal recumbancy head on edge of table, me crouching below at head level, pass tube carefully with ear at the adapter, listen for breathing sounds. 50% of the time this works on the first pass, if bunny appears to have laryngeal spasm/coughs, I will trickle a drop of lidocaine down the tube, give it O2 by flow-by or mask +/- a whiff of Iso, wait for 30 seconds then try again, usually 75% success on second pass. I can tube 90% of rabbits down to 1kg with a 2.5 mm uncuffed tube this way but if I fail with 2 further attempts I will abort and mask them so as not to traumatise the arytenoids as Marie suggest. I've not found the risk any greater with a mask just more difficult to get a stable plain of anaesthesia - usually too light rather than too deep.

RE: Rabbit GA protocols

Neil Wheadon — Thu, 12 Apr 2018 16:22:48 GMT

In the practice I'm in

Preperation

Ears clipped and EMLA, catheter in ear

Metacam (dog) 0.1ml/kg S/C

Metaclopramide 0.2ml/kg

Premed/induction

Pre-oxygenate

Ketamine 0.13ml/kg IM

Medetomidine 0.17ml/kg IM

Buprenorphine 0.1ml/kg IM

Fluid bolus 10ml/kg (half S/C , half IV)

Post Op

Second fluid bolus 10ml/kg

Atipamazole 0.2ml/kg IM

Consider Ranitidine 0.12ml/kg PO

Neil

Interesting thread, will be thinking twice if not three times about metaclopramide now

RE: Rabbit GA protocols

Marie Kubiak — Thu, 12 Apr 2018 16:22:01 GMT

[quote user="David Mills"]

[quote user="Marie Kubiak"]Wow, I thought we had moved on from the 'rabbits just die under anaesthesia' view of a decade or two ago! I have lost one 'healthy' rabbit in 12 years under anaesthesia and would be massively concerned to be losing them as regularly as you expect and would certainly be reviewing how anaesthesia was carried out.[/quote]

Le sigh.

It depends doesn't it. Partly on how many you are anaesthetising per week (at a guess we do maybe one a week if that) , expertise of the veterinary and nursing staff, etc etc.

They are inherently bad candidates for examination, hospitalisation and anaesthesia compared to dogs and cats. Surely better to recognise that fact than try and pretend all is rosy in the garden.

And if it is rosy, surely someone in your position could very quickly knock up a nice paper to show us how?

[/quote]

The myth that rabbits are terrible patients is perpetuated by vets assuming they are lost causes and persuading owners not to pursue treatment/diagnostics until they are moribund (and then they are likely to die!) or not providing equivalent standards of care as for cat/dog patients then being surprised they don't fare as well as cats/dogs. For routine procedures in young animals, accepting regular deaths and not reacting to improve the situation is a poor standard of care.

There are many papers comparing rabbit anaesthesia protocols (and CRI analgesia) available, most of us end up choosing one or two protocols that we fit with our caseload/drug availability/familiarity and adapt or change completely if it doesn't work to the standards we expect.

Marie

RE: Rabbit GA protocols

Marie Kubiak — Thu, 12 Apr 2018 16:11:51 GMT

[quote user="Jimbob"]

Thanks Marie, I really appreciate the advice. Would you be and to provide the doses you use for your IV protocol. Very interesting about the prokinetic use also.

[/quote]

Buprenorphine 0.06mg/kg, midazolam 0.5mg/kg, medetomidine 0.1mg/kg. I use the same doses IM for sedation,

Marie

RE: Rabbit GA protocols

Emily Rainbow — Thu, 12 Apr 2018 13:25:06 GMT

[quote user="David Mills"]

[quote user="Ivan Crotaz"]Medetomidine is perhaps not the ideal drug for patients with renal/cardiac/circulatory issues; use the same thinking on drug choices as you would for dogs and cats.[/quote]

Medetomidine is one of the best drugs to use where there are renal and, to an extent, cardio, issues.

[/quote]

I watched a feline anaesthesia webinar on The Webinar Vet a few weeks ago who said that medetomidine reduces renal perfusion so avoid in renal cats?

RE: Rabbit GA protocols

Clive Ansell — Thu, 12 Apr 2018 12:39:59 GMT

I'm using Medetomidine and Methadone premeds in cats and dogs at the moment, works really well and I like it.

Going back to the OP and Rabbits; I prefer Dom/Ket/Buph + Metacam pre op, but am considering using Methadone instead of Buph. Not used Midazoloam in rabbits much, but given how well the quad combo works in cats, might give it a try. Don't routinely give Metoclopramide or Baytril.

RE: Rabbit GA protocols

Neil Wheadon — Thu, 12 Apr 2018 09:04:56 GMT

[quote user="David Mills"]Medetomidine is one of the best drugs to use where there are renal and, to an extent, cardio, issues.[/quote]

Agreed, it is a very underated drug and provides great premeds for cats and dogs. I have the absolute pleasure in locumming for a vet who lectures on anaesthesia and his recipe for sedating cardiac cases involves medetomidine.

Neil

RE: Rabbit GA protocols

David Mills — Thu, 12 Apr 2018 01:07:28 GMT

[quote user="Ivan Crotaz"]Medetomidine is perhaps not the ideal drug for patients with renal/cardiac/circulatory issues; use the same thinking on drug choices as you would for dogs and cats.[/quote]

Medetomidine is one of the best drugs to use where there are renal and, to an extent, cardio, issues.

RE: Rabbit GA protocols

Ivan Crotaz — Wed, 11 Apr 2018 23:27:00 GMT

Dear James

ET placement - there is some disagreement on this, but the following is my opinion!

I recommend placing ET tubes using a guided method. You can do this using a semi-rigid endoscope (the best one is made by MAI), by threading the tube over the scope and literally looking at where you are placing it.

If no slim rigid scope is available, a medium cone (clean and smooth!) otoscope works very well - rabbit in sternal position, head moderately extended, check the mouth, spray lidocaine in pharynx/larynx, wait 60 sec, elevate soft palate and then look over the base of the tongue, heading in a ventral direction and you should see the larynx suddenly appear. I then 'intubate' with a soft thin urinary cathether, then remove the scope and thread the ETT over the top. Check placement using a capnograph as accidental oesophageal intubation is very common when you're learning. Best to practice on a cadaver first if you can. Very tricky to use this on dwarf rabbits - then the v-gel or rigid scope becomes the safest method.

I don't like blind intubation - my concern is that a small tube hitting the arytenoids several times before intubation is much more likely to give issues with airway trauma and laryngospasm. However there are quite a few exotics specialists that do use this technique and don't report problems. If you have the option though, it seems common sense to look at what you're doing!

Personally I use v-gels most often (I was heavily involved in their development so I am biased); I find them easier to use than a tube and they don't give me problems maintaining the airway. It is important to support them correctly then you shouldn't have too many problems with them displacing.

For my iv induction I'm currently using:

Medetomidine 0.03 - 0.1mg/kg i/v (reverse with same volume of atipamazole)

Buprenorphine 0.03 – 0.05mg/kg i/v

Ketamine 3 - 5mg/kg i/v

I decrease doses for older patients, otherwise I normally draw up a mid range dose, then give about 50% IV, wait 1-2 minutes then administer in small boluses to achieve a plane of anaesthesia sufficient to place a v-gel or tube. Lower doses give a noticeably shorter period of anaesthesia. Be cautious about dose rates as the required amounts vary depending on stress levels and other local factors. Medetomidine is perhaps not the ideal drug for patients with renal/cardiac/circulatory issues; use the same thinking on drug choices as you would for dogs and cats.

Good luck!

RE: Rabbit GA protocols

Jimbob — Wed, 11 Apr 2018 22:11:43 GMT

Thanks Marie, I really appreciate the advice. Would you be and to provide the doses you use for your IV protocol. Very interesting about the prokinetic use also.