Cushings or not Cushings?

Re: Cushings or not Cushings?

Rory Bell — Thu, 06 Nov 2014 09:50:02 GMT

Regardless of whether this dog actually ever had HAC or not I would share your concern that a fairly low dose of vetoryl has seemingly sent the adrenals to hell in a handcart. Without wishing to seem patronising; but I assume there is no other identifiable cause for hyperkalemia (renal failure, 3rd space / GI fluid loss etc) and/or post ACTH cortisol concentrations are truely suppressed?

That being the case, then its worth bearing in mind that a very small proportion of dogs with HAC treated with trilostane will have massive adrenocortical necrosis in a manner previously seen with mitotane treatment. Generally speaking, these dogs wil present in an addisonian crisis and the ensuing hypoadrenocorticism is permanent. For this dog therefore, I'd be very careful to monitor it's adrenocortical / electrolyte status and bear in mind that gluco- and mineral-cortocoid supplementation may need to be permanent.

cheers

Re: Cushings or not Cushings?

David Mills — Wed, 05 Nov 2014 23:57:13 GMT

[quote user="james herriot lied"]Just out of interest, how long did the atrial standstill persist?[/quote]

About 2-3 hours. Treatment was NaCl and IV calcium q20m (3 doses).

Was admitted as bradycardic, HR about 40. The escape rhythm was irregular which was a bit concerning (though dog bright) and looked high ventricular in form. Wasn't continually monitored on ECG (not possible here) but had intermittent ECGs which showed a progression from complete lack of activity to some P waves and normal complexes interspersed with escape rhythm (about 2h post-fluid commencement), then some junctional complexes in amongst normals before normals taking over. There are some odd premature complexes even now, 9 hours down the line.

Re: Cushings or not Cushings?

james herriot lied — Wed, 05 Nov 2014 23:24:38 GMT

[quote user="David Mills"]

Must say I'm surprised at the level of suppression though - this dog is on <2mg/kg vetoryl and reading the data sheet it states that normal dogs were dosed upto 36 mg/kg without ill effects.

[/quote]

Quite. I'd love to see a reference for the effects of vetoryl on entirely normal dogs.

Just out of interest, how long did the atrial standstill persist?

Re: Cushings or not Cushings?

John Flynn — Wed, 05 Nov 2014 23:09:41 GMT

[quote user="David Mills"]but only 40-60% specific meaning there are quite a lot of false positives[/quote]

and you can imagine the poor positive predictive value if applied to dogs with such helpful signs as "vague lethargy" etc..., no significant elevation in ALKP or stress leukogram...

arguably the LDDST is of most use in trying to "rule-out" cushings, but again, how often do I find myself in that situation...

(and that sensitivity value does creep down also a bit if operator error and "small volume of drug not administered iv" is taken into account... a bit like that marvellous 99.9% specificity of comparative bovine intradermal TB testing I keep hearing rumours of... of course no vet ever injects the guns the wrong way round or anything stupid outside of laboratory conditions...)

Re: Cushings or not Cushings?

David Mills — Wed, 05 Nov 2014 22:36:34 GMT

[quote user="John Flynn"]

I think another interesting question is would you have any real interest as to whether a 12 year old JRT with slight weight gain and mild PUPD had cushing's or not?

I would not have been interested in answering this question, and therefore would not have done a LDDST in the first place.

[/quote]

I quite agree. Inherited case (aren't they all out of hours?) and I wasn't involved in the work-up until now. Lovely atrial standstill on ECG though, and a scary intermittent ventricular escape rhythm. Not seen one for a while.

[quote user="james herriot lied"]We had a patient which had obviously been over-suppressed - for the second time - leading to fears that we might originally have jumped the gun on an increased ACTH stimulation.[/quote]

Interesting. I never did like ACTH stims when we had synacthen. But, reading around some sites and papers, LDDST is thought to be 90-95% sensitive (dependent on PDH or ADH), but only 40-60% specific meaning there are quite a lot of false positives - perhaps this is old news to most but I thought the specificity was considerably higher.

[quote user="james herriot lied"]Were the initial symptoms consistent with anything else (the answer, of course, being yes)[/quote]

Clin notes from colleague state breathlessness (has bronchitis anyway), weight gain and mild PUPD...

Must say I'm surprised at the level of suppression though - this dog is on <2mg/kg vetoryl and reading the data sheet it states that normal dogs were dosed upto 36 mg/kg without ill effects. I'm hoping that this isn't acute adrenal necrosis...

Re: Cushings or not Cushings?

John Flynn — Wed, 05 Nov 2014 22:20:27 GMT

I suspect you know the answer too

I think another interesting question is would you have any real interest as to whether a 12 year old JRT with slight weight gain and mild PUPD had cushing's or not?

I would not have been interested in answering this question, and therefore would not have done a LDDST in the first place.

Had I got this far, I would most certainly stop and let the dog return to its pre-treatment state.

Incidentally, I'm always concerned when I see dramatic conclusions on welfare issues reached based primarily on blood cortisol levels... but that's another topic altogether...

Re: Cushings or not Cushings?

james herriot lied — Wed, 05 Nov 2014 22:11:09 GMT

I had an interesting conversation with one of the medics at our external lab, a couple of weeks ago. We had a patient which had obviously been over-suppressed - for the second time - leading to fears that we might originally have jumped the gun on an increased ACTH stimulation. We decided, given initial symptoms, response, likelihood of adrenal pathology rather than pituitary and timeframe, that it was genuine; but he reckoned that a large proportion of the initial follow-up stims that they see indicate that the dog doesn't have Cushing's in the first place.

That said, I'd give this dog a month off meds and reassess. Were the initial symptoms consistent with anything else (the answer, of course, being yes)

Re: Cushings or not Cushings?

Kate Richardson — Wed, 05 Nov 2014 21:42:30 GMT

Not sure of the normals re cortisol but I'm not sure I would have started treatment based on mild symptoms and no urine test- prob wouldn't have done Lddst without checking urine first anyway.

Re: Cushings or not Cushings?

David Mills — Wed, 05 Nov 2014 21:28:23 GMT

[quote user="Kate Richardson"]Did it have other changes on bloods? Urine results? Pre treatment I mean

[/quote]

ALP raised 274 (212), all else normal, urine not tested as far as I can see.

Re: Cushings or not Cushings?

Kate Richardson — Wed, 05 Nov 2014 21:22:49 GMT

Did it have other changes on bloods? Urine results? Pre treatment I mean