Young cat with sudden onset seizures - possible shunt?

Re: Young cat with sudden onset seizures - possible shunt?

Anthony Dennison — Sun, 12 May 2013 12:39:46 GMT

If I remember some tutorials in final year, lactate isn't just metabolised in the liver though, it's used all over the body, so it's not as much of a risk. That might be me getting my wires crossed however!

The cat has been fine since it's last dose of phenobarb last night, and is currently contently curled up asleep. She has an incredible appetite and is currently stable, all parameters normal. The owner is unwilling to pay out for everything all at once, but if further investigations are needed they will probably done one at a time to spread costs.

In the back of my mind I think this was a toxin ingestion (despite the owners insistence) - she is no longer salivating and seems to be acting like animals that I have previously treated for similar things, just sleeping it off. Low urea/creatinine/potassium is possibly linked to how small she is. I may have heard hooves and thought Zebra... who knows. I can't convince the owner to let me do further tests, symptomatic treatment has been succesful for now, and she seems happy with this, despite the fact I've warned her we don't know the underlying cause!

Re: Young cat with sudden onset seizures - possible shunt?

Yantha Smyth — Sun, 12 May 2013 11:28:17 GMT

I too had the understanding from CPD medicine lectures that hartmans should be avoided with shunts and impaired liver function due to inability to metabolise the lactate

Re: Young cat with sudden onset seizures - possible shunt?

jd2008 — Sun, 12 May 2013 10:24:46 GMT

I've just realised I didn't answer your points at all Chris Oops!

Basically, liver function would need to be severely compromised (to the point of end-stage) to affect lactate clearance. Any reduce renal clearance you should be able to rectify fairly rapidly by improving perfusion with fluid therapy (and active warming if the patient if is hypothermic - especially cats) so hartmanns is absolutely ok in almost all shunt cases. In short, don't worry about lactate clearance

It's pretty reasonable to assume, if you don't have access to analysis, that these cases have a metabolic acidosis and are acidaemic. A good chunk of that acidosis you'll correct with adequate fluid therapy but NaCl will make the acidaemia worse, especially in the short term and that can be a disaster for cats who can easily have pH's of 6.9 to start with.

P.S. sorry for the slight highjack

Re: Young cat with sudden onset seizures - possible shunt?

jd2008 — Sun, 12 May 2013 09:34:44 GMT

[quote user="Christopher Saul"]

to explain the logic behind my mentioning saline there: ( my concern being the lactate in hartmann's causing a lactic acidosis)

I know that the liver has a significant reserve for clearance of lactate (correct me if I'm wrong but I believe the liver goes on clearing lactate until hepatic blood flow goes down to about < 30%), and also lactate is cleared renally as well as hepatically.

I was thinking..... if liver function is severely enough compromised to cause HE, then lactate clearance may become a problem. I concede that this is based on no science whatsoever but I always worry a little about lactic acidosis in these cases. I was also thinking that maybe there may be reduced renal perfusion which may impede lactate clearance. I guess ringers would be a compromise but most practices over here don't routinely stock it (I don't think?)

However I'm always happy to be corrected if there is superior knowledge out there...

Chris

[/quote]

Hi Chris,

Aha! this is where it gets interesting : lactate does not cause acidosis. It actually uses up two hydrogen ions in its production so the term lactate acidosis is incorrect.

Robers, Farzenah and Parker, Biochemistry of exercise-induced metabolic acidosis. Am J Physiol Integr Comp Physiol 287:R502-R516, 2004 explains it much better than I can.

You are right, hepatic lactate clearance continues in the face of significantly reduced blood flow so I wouldn't be worried about lactate clearance in a shunt patient. An end-stage liver failure case maybe.

And I really wouldn't use NaCl !!

(I spent 16 years in practice in the UK before coming to Oz and everywhere I worked had Ringers - maybe I was lucky, or is it falling out of fashion now?)

Cheers,

Jane

Re: Young cat with sudden onset seizures - possible shunt?

Christopher Saul — Sun, 12 May 2013 08:34:28 GMT

[quote user="Jane Adams"]

[quote user="Christopher Saul"]

[quote user="Anthony Dennison"]I don't really want to put the cat on fluids right now due to low urea/creatinine and also the hypokalaemia, would it be best to start anyway and just supplement potassium?[/quote]

Remember to avoid hartmann's because of the possibility of a shunt. I would go saline/potassium. Give lactulse per rectum, and even consider a lactulose/warm water enema. Could give synulox subcut if owners cant afford IV antibiotics.....

Chris

[/quote]

I'd be very wary about using sodium chloride. It's an acidic fluid and this cat has likely got quite a significant metabolic acidosis (and possibly a respiratory acidosis too if there's hypoventilation after seizuring and anticonvulsant therapy).

[/quote]

I feel I ought to explain the logic behind my mentioning saline there: ( my concern being the lactate in hartmann's causing a lactic acidosis)

However I'm always happy to be corrected if there is superior knowledge out there...

Chris

Re: Young cat with sudden onset seizures - possible shunt?

jd2008 — Sat, 11 May 2013 23:19:42 GMT

[quote user="Christopher Saul"]

Chris

[/quote]

We don't use NaCl much here: mostly combined with glucose as 'half-strength' for free water deficits or in truly chloride-responsive metabolic alkalosis (uncommon).

Most of our shunt patients do fine on hartmanns but if we are particularly concerned we'll use ringers.

But yes, absolutely must correct the hypokalaemia.

And I agree 100% that there's no indication for the use of corticosteroids in hypovolaemic, cardiogenic or septic shock. If anything they have the potential to worsen GI mucosal damage caused by hypoperfusion

Cheers,

Jane

Re: Young cat with sudden onset seizures - possible shunt?

Christopher Saul — Sat, 11 May 2013 22:36:37 GMT

[quote user="Michael Woodhouse"]I don't unless anaphylactic...........[/quote]

Glad to hear it!

Re: Young cat with sudden onset seizures - possible shunt?

Michael Woodhouse — Sat, 11 May 2013 22:34:46 GMT

[quote user="Christopher Saul"]There is no evidence that steroids give any benefit whatsoever in shock - in fact there is evidence to the contrary - but plenty of people still seem to use 'em....[/quote]

I don't unless anaphylactic...........

Re: Young cat with sudden onset seizures - possible shunt?

Christopher Saul — Sat, 11 May 2013 22:20:20 GMT

[quote user="Michael Woodhouse"]

Is there any evidence that IV is better?

[/quote]

Not sure TBH, and perhaps not, but I was replying to Anthony who had commented that the owners couldn't afford IV antibiotics. In any case, remember that the subcutaneous route is in general not so effective in dehydrated patients, so there is reasonable logic to using IV where dehydration is present, though I concede not at other times.

There is no evidence that steroids give any benefit whatsoever in shock - in fact there is evidence to the contrary - but plenty of people still seem to use 'em....

Re: Young cat with sudden onset seizures - possible shunt?

Michael Woodhouse — Sat, 11 May 2013 21:48:43 GMT

[quote user="Christopher Saul"]Could give synulox subcut if owners cant afford IV antibiotics.....[/quote]

Is there any evidence that IV is better?

*Think* it was Malcolm Ness who had a student do some research and found blood levels from s/c Synulox = IV after about 30 mins.

I thought the human product was IV as people don't tend to appreciate s/c or i/m injections so those not eating get the drug IV and those eating take it orally.

Re: Young cat with sudden onset seizures - possible shunt?

Christopher Saul — Sat, 11 May 2013 21:33:11 GMT

Yes. Hypokalaemia is not a reason to withold fluids, just spike the bag with potassium.

I can't add an awful lot to what the others have already said, it certainly could be a shunt I guess. The fact it has responded to anticonvulsant therapy doesn't rule out a shunt IMO; they don't all read the text books.

Chris

Re: Young cat with sudden onset seizures - possible shunt?

Anthony Dennison — Sat, 11 May 2013 21:20:51 GMT

I gave phenobarb i/v at 5pm (12mg/kg dose) this evening as fits seemed to be getting slightly worse, this knocked her for six and she was very sedated. She started coming round and seemed to be responding, then had another seizure at 8.30pm.

Problem being is that money is limited so to be honest starting i/v antibiotics and fluids will push over the budget and it will be hard to convince the owner that. I'm having a hard enough time trying to convince her to get the ammonia tested!

If I remember rightly, Hepatic Encephalopathy seizures don't respond to normal anti-seizure medication, which this seems to have done, so does that makes shunts less likely?

Re: Young cat with sudden onset seizures - possible shunt?

Yantha Smyth — Sat, 11 May 2013 20:39:25 GMT

It does sound like a shunt is possible (amongst some other things too infectious,toxic etc)

I would definitely start on IV saline with maint levels potassium, give an antibiotic like ampicillin or amoxy, and give lactulose at least until you can get a bile acid result.

None of those treatments are going to matter much/at all if not a shunt, but may well help to stabilise if it is.

I once had a young cat, neuro presentation, history of recurrent urt infections that turned out to be a shunt and that did stabilise well over 12hrs with above treatment

Good luck

Yantha

Re: Young cat with sudden onset seizures - possible shunt?

Claire Fisher — Sat, 11 May 2013 18:35:24 GMT

Toxoplasmosis?

Can you check ammonia - if you have a vettest but don't keep a box of ammonia slides I believe there is usually one in the quality control clip!

Re: Young cat with sudden onset seizures - possible shunt?

Anthony Dennison — Sat, 11 May 2013 16:09:42 GMT

Update - she's had a fit almost every hour, on the hour. Can almost set my watch by it, except when I placed an i/v catheter and gave some colvasone i/v, but that doesn't seem to have done anything as she then had another seizure an hour later.

Any more ideas please?!

Re: Young cat with sudden onset seizures - possible shunt?

Lynn Broom — Sat, 11 May 2013 14:44:47 GMT

Consider dry FIP. Can cause seizures as well as affecting other organs & biochem/haem findings can vary greatly. Can respond to immune suppressant drugs in the short term.