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Transcript of the video:
hello clinical problem solvers, This is Rabbi. we’re gonna be talking about hemolysis today.
Now, I bet red blood cells, wish they could live forever, but in reality, they only live for about a couple of months.
Our goal today will be to practice thinking about the common causes of the hemolytic anemia the mimics of hemolytic anemia, but also to leave you with a systematic way of thinking about this problem.
In reality, though, when people present with is you’re probably dealing with one of these four diagnoses, autoimmune hemolytic anemia, G6PD deficiency sickle anemia and micro-angiopathic hemolytic anemia.
There are also a couple of things to be mindful of when working up hemolysis and not arriving at an answer. These are mimics of hemolysis. Which includes the destruction of red blood cells prematurely in the bone marrow referred to as “intra-medullary hemolysis, and also a hematoma, the breakdown of red blood cells outside the vascular system. So again when dealing with hemolysis asked herself at being fooled by intramedullary hemolysis or a hematoma. And in reality you’re probably dealing with one of these four common diagnoses.
But now let’s develop a systematic way of thinking about hemolysis which we’ll deploy in cases where we’re having a tougher time finding the diagnosis. Our systematic approach to hemolysis will fundamentally break down the problem into three different categories: hemolysis arising because of a problem in the environment, hemolysis arising because of an issue on the red blood cell membrane or because of something inside the red blood cells. Issues arising within the environment of the red blood cell include micro-angiopathic hemolytic aneamis, examples of which include TTP, HUS, and DIC. These causes have a characteristic smear finding which is the presence of schistocytes. And in contrast with the scary causes of micro-angiopathic hemolytic anemia, occasionally red blood cells can be destroyed due to directtrauma from a heavy foot strike. And in these patients the smear is typically normal.
In terms of problems on the red blood cell membrane, it’s a good idea to divide it into intrinsic issues with the red cell membrane or something on the red cell membrane, thus mediating hemolysis.
Primary issues with the red blood cell membrane include a deficiency in the anchoring proteins. This leads to hereditary spherocytosis, which as you can imagine, typically has spherocytes on the peripheral smear. A deficiency in the “cd5 or cd59, is what results in Paroxysmal Nocturnal Hemoglobinuria. In these patients to smear is typically negative.
There a whole variety of lipid disorders that can result in hemolytic anemia, the most common of which is chronic liver disease.
There’s also this fascinating diagnosis called Zieve Syndrome, which refers to hemolytic anemia in the context of alcoholic steatohepatitis.
On extrinsic causes on the membrane this is probably the most common cause of hemolytic anemia in an adult and refers to the presence of an antibody on the red blood cell membrane. We divide autoimmune hemolytic anemia into warm and cold [autoimmune antibodies]. In warm autoimmune hemolytic anemia, it’s reasonable to expect the presence of spherocytes. Inn cold-mediated antibody disease. You can have spherocytes or occasionally rouleax formation.
Tune into our episode on the clinical problem solvers for more about these two causes and finally, moving on to problems within the red blot cell membrane.
Again, let’s divide this into intrinsic issues or something from the outside.
So, intrinsic issues can either be a hemoglobinopathy, a prime example of which is sickle cell disease where of course you’ll find sickle cells on the peripheral smear. or enzyme deficiencies, like G6PD.
This also has some interesting smear findings including bite cells and heinz bodies.
now extrinsic issues that can make it all the way inside the red blood cell include certain infections like malaria and babisia, toxins like snake venom and electrolyte issues an excess of copper in Wilson’s disease can lead to hemolysis as can in a low phosphorus.
Alright, let’s recap. Hemolysis refers to the accelerated destruction of red blood cells.
The most common causes are autoimmune hemolytic anemia, G6PD deficiency, sickle cell disease and micro-angiopathic hemolytic anemia.
In cases where you’re having trouble getting to the bottom of it, make sure to run the list of mimics, intramedullary hemolysis or a hematoma.
It’s probably a good idea in those cases where you’re having a hard time answering the cause of hemolysis is to ask yourself: Well, where is a problem, in the environment, in the membrane, or on the inside of the cell.
You’ll realize that the peripheral smear, is very informative.
Schistocytes tell you the problems in the environment as a result of microangiopathic hemolytic anemia.
Spherocytes typically mean that the problem is on the membrane either in the form of a deficiency in anchoring protein or an antibody.
Intrinsic causes leave their signature in the form of sickle cells, bite cells, or if it’s an infection, envenomation or electrolyte issue, typically a completely normal smear.
Alright folks, thanks so much for tuning in…
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