Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Anthony Todd — Sat, 04 Oct 2014 08:05:12 GMT

Dunno why it posted twice??

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Anthony Todd — Sat, 04 Oct 2014 08:03:06 GMT

[quote user="John Flynn"]

Just to throw another GP apprqaoch under the microscope:

I tend to sedate with ACP/midazolam/buprenorphine IM and find that about half either piddle themselves or can have the bladder squeezed with careful but firm pressure. I always think of ketamine as making muscle (such as that in the urethra) rigid, so personally avoid it (that may be an irrational avoidance).

If not (and nothing to be milked out end of penis), then I tend to squirt some lidocaine on the penis, followed a minute later with some local up the urethra, and then proceed to catheterize.

WOuld be interested to know if local up the urethra is a no-no as I've not knowingly had problems, but appreciate my caseload is not large enough to draw any meaningful conclusions.

Still end up GA'ing some, but can't remember the last one off-hand.

[/quote]

+1 word for word, but just Acp to start. The caseload, in the days of Go Cat, was large!

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

John Flynn — Fri, 03 Oct 2014 22:48:56 GMT

Just to throw another GP apprqaoch under the microscope:

If not (and nothing to be milked out end of penis), then I tend to squirt some lidocaine on the penis, followed a minute later with some local up the urethra, and then proceed to catheterize.

WOuld be interested to know if local up the urethra is a no-no as I've not knowingly had problems, but appreciate my caseload is not large enough to draw any meaningful conclusions.

Still end up GA'ing some, but can't remember the last one off-hand.

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Anthony Todd — Fri, 03 Oct 2014 17:55:23 GMT

[quote user="Gareth C."]methadone really useful [/quote]

Did you get a "pain" response during the unblock? Ie did you get an indication that you may be causing damage/trauma to the urethra, which is my main reason for being opposed to GA unless you fail without it.

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Gareth C. — Fri, 03 Oct 2014 17:42:45 GMT

since comfortan has been launched have found methadone really useful and have managed to do one just using that as a sole agent for cathetrisation

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Anthony Todd — Wed, 01 Oct 2014 23:31:47 GMT

[quote user="Dalya Livy"]I'm not convinced modelling therapy on human methods would be appropriate.[/quote]

Er, um, well, yes, perhaps not....must brush up on my basic histology.

Pleased that the piece mentions other drugs, which seem totally unrelated to the urinary tract and with evidence, which may help blocked cats, even if my suggestion was roundly and swiftly kicked into the long grass.

Acp does quite well too in the first citation.

I must contend though, that if you unblock the cat the metabolic chaos resolves quickly and, bearing in mind the discomfit and pain, I still think it's better to unblock ASAP and support later, although IMHO they seem to recover really quickly.

I seem to recall that, although blocked cats are hyperkalaemic when blocked this is reversed very quickly after unblocking so you get a reflex diuresis and hypokalaemia very quickly so you may be chasing [K++] levels.

But I may be way out of date.

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Dalya Livy — Wed, 01 Oct 2014 16:29:49 GMT

Striated muscle in feline urethras is post-prostatic, and smooth pre-prostatic; the reverse is true in humans. Given that most feline obstructions are post-prostatic, I'm not convinced modelling therapy on human methods would be appropriate.

Because I'm boring, I went and looked. There is a study form 1996 which looked at effects of ACP and phenoxybenzamine on feline urethras and found they had an effect on smooth muscle, but no effect on post-prostatic urethra. http://www.ncbi.nlm.nih.gov/pubmed/7574161

Similarly a study looking at dantrolene and prazosin found dantrolene relaxed both smooth and skeletal components and did therefore relax post-prostatic urethra, but whether it facilitated catheterisation was not conclusive. http://www.ncbi.nlm.nih.gov/pubmed/7574161

Also, a bit randomly, amitriptylline has apparently been effective at getting male cats to eliminate urinary calculi and reverse ARF within 72h - no description of other treatments employed concurrently (and implication is that none were), or size of uroliths - but the postulated mechanism is relaxation of smooth muscle which should not make sense based on anatomy so perhaps my first paragraph needs correcting or there is some data missing here (the paper does make some glaring omissions, but that's too much to go into really). http://www.nature.com/ki/journal/v64/n4/pdf/4494028a.pdf

What I'm trying to say in a convoluted way is that a) sedation still deserves supportive care/monitoring and b) obstructed cats are kind of like cruciates - there are loads of different ways to do them because the one perfect way does not exist (yet). Anthony, you like ACP, it works for you - brilliant. I like midazolam/opiate/light GA after correcting metabolic issues, +/- lidocaine coccygeal block or urethral infusion - works for me. And KY. Lots of KY. Everybody happy. I hope :)

And PS the red star wasn't me, I don't like the anonymity of the star system so I don't use them (sorry Arlo)

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Anthony Todd — Wed, 01 Oct 2014 01:14:22 GMT

[quote user="Anthony Todd"]Once more unto the breach, dear friends, once more....[/quote]

If getting yet another anonymous red star stops one male cat having an amputated penis or urethrostomy because of a mutilated urethra after repeated traumatic "unblocks" I'll be happy regardless.

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Anthony Todd — Tue, 30 Sep 2014 23:56:41 GMT

[quote user="Anthony Todd"]urethral dilator drugs[/quote]

This is the "brand leader":

http://www.renalandurologynews.com/tamsulosin-aids-stone-expulsion/article/193855/

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Jenny Smith — Tue, 30 Sep 2014 22:28:00 GMT

[quote user="Anthony Todd"]

perhaps exploring some of the urethral dilator drugs used in humans. Even just infusing the urethra with them; the drug, orally, works brilliantly in humans.

[/quote]

It's my understanding that BZDs cause a degree of urethral relaxation, plus it's my 'favourite' sedation combo for the sickies. I aim to correct the metabolics as much as possible before sedation, but still acting quickly. So calcium gluconate on board, correct any hypovolaemia then sedate to unblock

Jenny

(I know I'm jinxing myself but I really want a nice blocked cat case now!)

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Jenny Smith — Tue, 30 Sep 2014 22:27:46 GMT

[quote user="Anthony Todd"]

perhaps exploring some of the urethral dilator drugs used in humans. Even just infusing the urethra with them; the drug, orally, works brilliantly in humans.

[/quote]

Jenny

(I know I'm jinxing myself but I really want a nice blocked cat case now!)

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Anthony Todd — Tue, 30 Sep 2014 19:21:32 GMT

[quote user="Dalya Livy"]I am also generally wary of articles which promote sedation as being safer than general anaesthesia without mention of supportive care or monitoring of the sedated patient, it can too often be assumed that they don't need any because it's "only" a sedative. [/quote]

Once more unto the breach, dear friends, once more.....

I have never, ever, had a cat die under Acp, whereas some references quote pretty high mortality with a GA [remember the biochem is way off normal; K+ through the roof etc. etc.]

The big advantage is that the cat reacts to urethral trauma as it's happening! I know it's a hobby horse and I've had so much flack but I think most dinovets will agree with me.

The number of repeat "FLUDT"s" is never quantified but I've seen a lot and, invariably, they were unblocked traumatically AND/OR had an indwelling catheter.

True, some are easier to unblock under full GA [and I've had my failures with Acp alone] but I'd suggest trying with Acp alone and perhaps exploring some of the urethral dilator drugs used in humans. Even just infusing the urethra with them; the drug, orally, works brilliantly in humans.

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Dalya Livy — Tue, 30 Sep 2014 16:50:53 GMT

I've used this block a few times in addition to premed/GA, and it does allow the anaesthesia to be quite light, just enough for the ET tube to be tolerated. I do like the effect, and catheterisation may be a little easier than without the block but haven't done enough to really say. It may also depend on whether it's a functional obstruction or a physical one.

What the article does not mention is doses of ACP and dexmedetomidine used to sedate these cats, or blood pressure values on these cats following sedation, or whether any supplemental oxygen is being given, all of which are pertinent issues in metabolic catastrophes that some of these cats can be.

I am also generally wary of articles which promote sedation as being safer than general anaesthesia without mention of supportive care or monitoring of the sedated patient, it can too often be assumed that they don't need any because it's "only" a sedative.

But then I'm feeling a bit crotchety today ;)

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Jenny Smith — Tue, 30 Sep 2014 16:37:48 GMT

This has been talked about quite a lot on the internal Vets Now discussion boards... from what I remember (although others may correct me!) the general consensus would be to use this technique when our usual tricks haven't worked.

Sods law being what it is, since reading up on how to do this, have I seen a blocked cat? Of course not!!

I would usually sedate them before unblocking anyway (midazolam/ketamine is my usual choice) so this would only ever by adjunctive for me

Jenny

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

David Shepherd — Tue, 30 Sep 2014 16:25:56 GMT

Maybe Michael should give it a try and let us know how he gets on?

It seems we rarely see blocked cats these days so not much chance of practising

David

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Linda Filshie — Tue, 30 Sep 2014 10:17:43 GMT

I would block in addition to GA/sedation but not instead of...

Re: Anybody uses Coccigeal epidural anaesthesia in blocked cats?

Braden Collins — Tue, 30 Sep 2014 01:16:13 GMT

I think the cat would have to be pretty flat to do this, or for that matter justify the risk of bites and scratches to staff. Never had one of these die under ga so not going to hurry to try this.