Saturday, October 21, 2023

Conclusion Caturday: Ruby Requests Rest (Case 1)

 

Picture of stuffed alpaca Professor Pocky and stuffed camel Douglas
Photo of TA Douglas (Left) and Professor Pocky (Right) taken by Dr. Haus
 

Click For Explanation of Case Flow

 

Click for Test Case Tuesday:  Ruby Requests Rest

 

Click for Thoughtful Thursday:  Ruby Requests Rest  

 

Quick Review


Diagnosis:

🌌IMMUNE-MEDIATED HEMOLYTIC ANEMIA🌌

 

Pathophysiological Point:

Ruby is suffering from a disease where her own body is producing antibodies AGAINST her own red blood cells.  This means her own body is destroying her red blood cells.

 

 Questions, Answers, and Further Information:

 

Level 1 Questions, Answers, and Further Information:

  1.  Explain why Ruby has a low number of red blood cells on her CBC.  (See Pathophysiological Point above for a hint)

    Ruby has a low number of red blood cells because her own body is destroying her red blood cells.  Even if her body is making more red blood cells they are being killed meaning she does not have enough red blood cells.

  2.  Why is having a low number of red blood cells in the body bad for a patient?

    Having a low number of red blood cells is bad for a patient because red blood cells bring oxygen to all the cells of the body.  The cells in the body need oxygen and if the body cannot bring oxygen to the cells the cells, and the patient, will die.

  3.  Challenge question, why is Ruby icteric on physical exam?  (Hint:  Icterus)

    Ruby is icteric on physical exam because her body is breaking down red blood cells at an increased rate.  Ruby's body/spleen (mentioning the spleen gets bonus points!) is removing the red blood cells from the body and when blood cells are broken down the body produces bilirubin.  If bilirubin is being created at an increased rate there is not enough time for the body to remove the bilirubin so the patient turns yellow, or icteric from excess bilirubin in the bloodstream (bilirubinemia).

    Helpful Links:

 

Level 2 Questions, Answers, and Further Information:

  1.  Given Ruby's disease process (see above), describe what is occurring at a cellular level to both the immune system cells and Ruby’s red blood cells.  Please be sure to address in your answer:
    • All blood cells involved in Ruby’s disease process (and how they are involved)
    • How the cellular changes are leading to her large and painful spleen

      Ruby’s disease process is activating her B-lymphocytes and leading to their differentiation into plasma cells.  These plasma cells are producing antibodies against Ruby’s own RBCs.  The antibodies are coating Ruby’s RBCs marking them for T-cell destruction.  Ruby’s T-helper cells are detecting the antibody covered RBCs and assisting the cytotoxic T-cells by activating them to destroy the RBCs.  The spleen recycles damaged and dead RBCs.  The large number of RBCs being recycled in the spleen is overworking the spleen leading to its large size and painfulness.

  2.  Explain pathophysiologically why Ruby is icteric on physical exam.

    Ruby is icteric on physical exam because of the excessive breakdown of red blood cells due to her diagnosis of Immune-Mediated Hemolytic Anemia.  In Ruby's case, her red blood cells are being marked for destruction by her own antibodies.  These antibody-coated red blood cells are detected in the spleen and the spleen breaks down the red blood cells.  One of the breakdown products of red blood cell breakdown is bilirubin.  This bilirubin is normally removed from the bloodstream by the liver to be excreted in the feces and urine.  For Ruby, she has such a large amount of red blood cell breakdown that her liver cannot keep up with the excretion of bilirubin, thus she has more bilirubin in the bloodstream than normal (hyperbilirubinemia) leading to her signs of icterus on physical exam (bonus points if you listed out the steps of bilirubin excretion).

  3.  Challenge question, explain why Ruby has both low red blood cells AND low reticulocytes.  (HINT:  Think about her disease process)

    IMPORTANT:  When RBC numbers are low, reticulocytes “should be” high.

    Reticulocytes are immature RBCs that should not be released from the bone marrow unless there is a large depletion of RBCs.  In Ruby’s case, the low reticulocytes are indicative of extremely severe disease.  Ruby should have large number of reticulocytes in her bloodstream to compensate for her low RBCs but in this case the antibodies are also destroying her reticulocytes.  Ruby’s bone marrow is completely depleted of RBCs AND reticulocytes meaning she is in an extremely severe disease state with total loss of oxygen carrying capacity.

    Helpful Links:

Level 3 Questions, Answers, and Further Information:

  1.   Describe the treatment plan you would recommend for Ruby and why you are recommending each part of your treatment plan.  Please answer this question as if you are speaking to a professional colleague.

    The answer to this question will be different depending on if you are approaching this question as a dog patient or a human patient.  I will answer this question in relation to a dog patient though the disease process and treatment plans are similar between dogs and humans.  As a reminder, I am not an internal medicine specialist.  😄

    Ruby has been diagnosed with immune-mediated hemolytic anemia (IMHA) and we need to immediately get her started on a blood transfusion (packed red blood cells or whole blood depending on what you have) due to her anemia.  Typically treatment starts with corticosteriods at an immune suppressing dose.  It is important to run further testing to determine underlying cause (tick-borne disease testing, cancer screening, etc.) because if we can find the underlying etiology we can create the best treatment plan.  Many clinicians will start doxycycline at this time to cover for an underlying infectious disease leading to the IMHA.  Patient's response to treatment will determine further interventions.

  2.  Describe your recommended treatment plan and why you are recommending each part of your treatment plan.  Please answer this question as if you are explaining it to a client/patient without a scientific background.

    Today we have diagnosed Ruby with a disease where her own body is attacking her blood.  Ruby's blood is important to bring nutrients to her entire body explaining why she is tired and not acting like herself.  We need to replace this blood Ruby has lost and treat her aggressively for her disease.  Due to Ruby's need for blood, we recommend Ruby to be hospitalized with 24/7 care until we can make her comfortable and stable.  The main treatment will be immune suppressing medication as it is Ruby's own immune system that is destroying her blood.  We need to stop her immune system so it will stop attacking her blood.

  3.  Explain the pathophysiology of at least TWO (2) different etiologies of Immune-Mediated Hemolytic Anemia.

    I am trusting you all to pick two etiologies of IMHA and to explain the pathophysiology of them.  Be sure to view the helpful links below that will contain research articles diving into the pathophysiology of the potential causes of IMHA.

    Helpful Links:

      

Day 3 Conclusion

I hope you enjoyed Ruby's case!  Don't forget to...

📚 Review material related to Ruby's case 

🤩 Get excited for upcoming cases



Dr. Haus's Unsolicited Life Advice: Practice explaining science to folks without a science background

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