Wednesday, February 23, 2011

Blood, blood everywhere....

Hemorrhage.  We've all seen it in the movies, we've seen it on TV, but have you seen it in a real-life emergency?  Depending on the patient's age, exposure, clinical signs, history, medications and other factors, the list of causes for bleeding can be quite extensive.  These critical patients require the efficiency, expertise, and dedication of the emergency veterinarians around the country who work around the clock, just in case they're needed.  And they often are.

I've still never forgotten the story of Sheeba, a sheltie who presented to me about one year ago.  She was about 3 years old, in great health previously, but had been lethargic and having increasing difficulty breathing for the last 1-2 days.  Her breathing was labored, and her gums were pale.  She had no history of trauma, and they did not witness her ingesting anything recently. No other symptoms had been noted, including no vomiting, diarrhea, or anything else unusual.

Immediately, a triage physical exam was performed.  Auscultation of her lungs suggested fluid in her chest cavity, or pleural effusion.   Pleural effusion is a build up of fluid between the surface of the lungs, and the body wall; typically there is only a very slight amount of fluid in this space which serves to lubricate the lungs as they move to and fro during the motion of breathing.

Oxygen was provided and a minimum database was collected to rule out causes of her symptoms.  (For those not familiar with medicine, a minimum database typically includes the quick, in-house, rapid testing that provides the attending with critical information to help make diagnostic and treatment decisions).  An IV catheter was placed.  Initial testing indicated blood loss was occurring, and in conjunction with her symptoms, the most likely location was her chest cavity.  Radiographs confirmed a severe amount of fluid within her chest.

Additional tests were performed to attempt to determine why Sheeba had been bleeding into her chest; in a young patient without a history of trauma, the most treatable (and arguably most common) cause of this is exposure to anticoagulant rat bait.  Testing, called PT (prothrombin time) and PTT (partial thromboplastin time), were performed, and both were severely elevated, indicating a deficiency in the clotting factors necessary to maintain hemostasis.   After talking to the family about her symptoms, signs, and test results, they remembered that rat bait was indeed placed under their house last week, and she was able to access this location.  Rat bait toxicity was our most likely culprit.

Anticoagulant rat bait works by inhibiting the enzyme vitamin k epoxide reductase, leading to a vitamin K deficiency in the body.  Vitamin K is a necessary factor for the production of clotting factors (II, VII, IX and X) in the liver.  As these factors are depleted, the body is unable to clot blood, and life-threatening hemorrhage occurs.  Unfortunately, the same pathway that is intended for pests is also the method of toxicity in our companion animals.  Bleeding can occur anywhere in the body; externally or internally, and symptoms vary widely as a result (bloody diarrhea, vomiting blood, difficulty breathing due to bleeding into the chest, bleeding from the nose or mouth, or death if bleeding occurs into the brain).

If you see your animal ingest anything unusual, especially a known toxin, the best course of action is to contact a veterinarian.  If caught quickly enough, they may induce vomiting to remove the toxin from the animal's system, potentially preventing toxicity.  Unfortunately, our pets are often able to ingest these types of things without our immediate knowledge, as in Sheeba's case. 

Sheeba was hospitalized, and fresh frozen plasma was administered in order to restore her body's missing clotting factors.  She was started on the antidote for this type of poisoning, vitamin K1.  Initially, she improved and her clotting times reduced towards normal values.  However, after the first 12 hours of hospitalization, her breathing worsened.  The amount of fluid within her chest cavity was overwhelming her lungs' ability to exchange life-sustaining oxygen for the waste product carbon dioxide.  She was near death, and her best chance of survival was to remove the fluid from around her lungs (called thoracocentesis). Doing so was not without risk, as removing this fluid required placing a needle into her chest cavity, a moderately dangerous procedure in a patient with a bleeding disorder. Her clinical status continued to deteriorate, and cautious thoracocentesis was her only chance for survival.  Her family agreed to allow the removal of just enough fluid to improve her respiratory rate, mentioning to me that they were strongly considering euthanasia, due to her disappointing progress and concern for the financial burden associated with treatment.  Her family visited with her, sobbing together, just prior to the procedure, just in case it was their last time.

I removed about 75ml of frank blood from Sheeba's chest while she lied laterally recumbent, gasping for breath, unable to do anything but focus on the effort of breathing.  After the fluid was removed, I monitored her closely. With almost instantaneous results, she sat up, looked around, stood up, and began to bark and wag her tail.  It was one of the most dramatic recoveries I have ever seen.  With tears in my eyes, I ran up to the lobby, called for her family, and brought them to Sheeba's kennel.  They hugged each other, they hugged me, and they celebrated.  The joy of this moment is forever frozen in my mind.

Sheeba never looked back.  The bleeding halted (thanks to plasma and vitamin K), the blood within her pleural space was reabsorbed back into her body (which normally occurs over about 48 hours once hemostasis is restored), and she went home 24 hours later, wagging her tail and into the arms of her thankful family.  

I heard from the family about 1 week later, and she was as good as new.  That's why I love the ER.

1 comment:

  1. Oh My God; I loved that story! Sometimes there ARE happy endings :)