Friday, June 24, 2011

An odd frustrating case...

Last night, I saw a case that totally stumped me.

The patient was an old (>13 years), small breed dog. He presented for acute onset of vomiting and lethargy. Before I saw the dog, I was thinking pancreatitis, gastroenteritis, cancer, and the like. When I saw the dog though, I was unsure. He was incredibly weak, swaying on his feet, and he was very mentally dull. There were no signs of pancreatitis really (no abdominal pain, no diarrhea, no fever, no other real abnormalities). Further, his blood pressure was 200! This likely explained why he was mentally not so with it.

Further investigation revealed a dog with severe, severe dehydration - far in excess of what I expected from 4 bouts of vomiting. Oddly though, his heart rate, which should have been sky-high to compensate for the dehydration, was actually rather low.

The combination of severe hypertension and a slow heart rate (bradycardia) is often a good indicator of cerebral edema ("swelling in the brain"). Initially, I was so fixated on the vomiting that I didn't make this obvious connection. I was so focused on the vomiting - trying to figure out where that came in...and thinking that was the primary symptom. Eventually, it dawned on me that there was something going on in this poor dog's brain.

Xrays showed an enlarged heart but no evidence of heart failure. Due to the severe dehydration, I started the patient on aggressive fluids, keeping a close eye on breathing. I also started an anti-hypertensive. I wanted to give mannitol, an intense diuretic that will decrease pressure within the brain. Given the dog's enlarged heart and significant dehydration, mannitol was a risky proposition. It would further dehydrate the patient and possibly push him into heart failure. On the other hand, his brain was obviously not functioning well and could have used the mannitol.

Urinalysis showed that the patient was dumping a massive quantity of protein into his urine.

So I was dealing with a myriad of different problems, unsure which was the primary one...

The patient continued to spiral down through the night. Despite treatment, his blood pressure never came down and his heart rate never came up. By the time morning came, I knew it was either referral time or heaven time.

The owners were distraught, and they elected euthanasia. It wasn't a bad decision. The dog obviously had something going on in its brain (tumor?), as well as a disease called protein losing nephropathy (the kidneys start to be unable to retain protein), and toward the end of the morning, he developed pulmonary edema from the large amount of fluids I gave him.

It was a terrible case, and I wish I had managed it better. Honestly though, I doubt it would have made any difference....

4 comments:

HDsheena said...

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Can'tSpell, DVM said...

Myself and Dr. May B. Insane have tried many many times to manage that two completly incompatable diseases- mitral insufficency and kidney disease. I've never had one do well and Insane has only had one or two that did. It sounds like you did the best you could...

Emergivet said...

I feel your pain. It's beyond frustrating to not be able to come up with a firm diagnosis. I'm betting on brain tumor causing cerebral edema and hypertension with reflex bradycardia. Then the PLN could be due to the hypertension. I don't have an explanation for the vomiting except perhaps due to severe headache or issues with the chemoreceptor trigger zone in the brain. The dehydration? Got me there.

The Homeless Parrot said...

Emergivet: Brain tumor was what I ended up telling them that morning, for lack of any other explanation. I offered referral, but they declined (wisely, I think). The whole picture didn't really fit. I was thinking that the dehydration could have been secondary to a tumor around the hypothalamus or somewhere up there that controls water intake/ADH, etc...maybe???