Tuesday, February 8, 2011

Lots and lots o' blood.

About a month ago, I was presented with an intriguing case. It was 6:30am, and I was soundly asleep in the doctor's bedroom. We'd had an uneventful night in the ER, and I did not expect the last couple hours to be any different. At 6:30am, my technician woke me up to let me know that a patient with bloody diarrhea was waiting to see me. I inwardly rolled my eyes and sighed. 6:30am? Bloody diarrhea? It couldn't wait a mere 1 hour to see the regular veterinarian?

I dragged myself from the dark, cold cocoon of the bedroom to see my patient. Waiting for me was a shepherd mix dog. I bent down to begin my physical exam. Upon rolling up her lip, I was confronted with almost grey, cold gums. I felt her femoral pulses and was startled to feel how weak they were. Her heart rate was thudding along at 150bpm. More worrisome still, frank blood was running out of her rectum. I'm not talking bloody diarrhea, I'm talking straight blood pouring from her.

Summoning my tech, we quickly placed an IV catheter and started bolusing her fluids. Her blood pressure was a measly 60 systolic (normal 100). As the fluids ran, we drew blood from her jugular to look at her blood values. About 15 minutes later, while the blood was running, she vomited on the floor. It was PURE blood.

As I waited for the bloodwork, I quizzed the owner. Was there rat poison in the house? Was the pet receiving steroids or NSAIDs such as Rimadyl or aspirin? Could she have gotten into any medications? The answer to all these questions was a resounding no. This was a responsible foster parent who took excellent care of her pets. At 3:15am that morning, the dog had been fine, baby-gated in the kitchen. We the owner got up at 5:15am, the kitchen was splattered with blood.

My patient responded somewhat to her fluids. Her bloodwork showed a low white blood cell count (all white blood cells), a low platelet count, and a low red blood cell count. Her total protein was also low. The numbers were only moderately decreased, and all of it pointed toward acute onset of severe bleeding. Her clotting times were elevated too. The odd thing was that her PT was elevated less so than her aPTT. That pretty much rules out rat poison, as in rat poisoning cases, the PT goes up first. That left me with maybe DIC (see sidebar), but from what?

I started thawing fresh frozen plasma for the patient, knowing she needed the clotting factors that plasma would provide her. Meanwhile, I told her mother that barring any toxins or medications that the dog had ingested, I was suspicious of peracute hemorrhagic gastroenteritis.

Hemorrhagic gastroenteritis is a poorly understood clinical entity that is seen in dogs frequently. It is characterized by rapid onset of extremely bloody diarrhea, vomiting, lethargy, and severe dehydration. Some cases can be severe enough to be life-threatening in a matter of hours. Or so I had read. I have seen tons of HGE, but I had never actually seen this sudden onset myself. The cause of this disease process (known as HGE) is widely debated but not known. Some veterinarians think E. coli, Clostridium, or Salmonella may be the root cause, but the answer remains unknown.

Fast-forward to my patient. She was discharged to her general practice veterinarian at 8am with a double unit of plasma. Miraculously, she responded to her plasma and fluids and was able to go home that night with no ill effects. Her presentation and bloodwork was not classic for HGE, but in the face of her presentation, I had no real answer for the owner. The good news is that regardless, she responded well to plasma and is alive today. It makes the point that sometimes knowing "the answer" is not the most important thing - sometimes just knowing what to do is enough. My patient lives to fight another day.

(There are other possible differentials for her condition but none of them really fit either, so the real answer remains at large - medication ingestion? toxin? HGE? weird Addisonian crisis? rat poisoning?)


Brittney said...

Did her vet prescribe vit K? If it was rodentacide toxicity the plasma with clotting factors would have been a band aid. I would expect her clotting times to get prolonged again after a couple days once the exogenous clotting factors were used up/degraded.

The HGE is a new one to me, we didn't cover it in small animal med. Thanks for posting the interesting case!

Holly said...

I was not there, but just reading about the frank blood from both ends sent my blood pressure and adrenalin surging. Holy cow.

Holly said...

forgot to add....glad she turned the corner!

The Homeless Parrot said...

Brittney: classic rat poisoning sees the PT elevated more than and earlier than the PTT. The rodenticide effects the clotting factor with the shortest half-life, which is 7, part of the extrinsic pathway. PT measures this, and thus, should elevate first and more.

But, to answer your question, yes, I did start oral vitamin K, and I am sure the rDVM sent the dog home on it to be safe. They don't all read the book!