Transcription
Hey. What's up people? Thank you for clicking on the video. This video is part of our series in hematology oncology, and we've been discussing the RBC's, reticulocytes, and let's talk about anemia. Tired and pale, pale and tired.
But first, what's the definition of anemia? Whenever you're studying anything, the first thing to know is what's the definition? There are many definitions of anemia. Like, it's the decreased oxygen carrying capacity of the blood. What does this mean?
The ability, the capacity of the blood to carry oxygen is less or decreased total RBC mass. Imagine that you are this person and this is the total mass of RBCs in your body. If the entire mass is decreased, that's anemia. Okay. But to measure the total RBC mass in our bodies, we need something called RBC nuclear scan, which is very expensive and not practical.
So we need some simple lab tests like hemoglobin, hematocrit, RBC number or concentration. So these are some parameters to measure the RBC mass, not literally, but they are indicators of the RBC mass. Remember, in physiology, we have a concept called oxygen content. Okay? It's a total that depends on many parameters like the hemoglobin concentration, the percent oxygen saturation, saturation of oxygen.
And the p a o two, which is the partial pressure of oxygen or partial oxygen tension. And we can remove this a. Okay. It's not a big deal. So what is hemoglobin concentration?
This is the hemoglobin. Okay. Like this has subunits alpha and beta and has the heme, okay, which has the iron. Alright. So hemoglobin concentration is a concentration of hemoglobin in your body.
Okay. That's totally different from percent saturation or oxygen saturation. Because saturation is the oxygen carried by the hemoglobin. The oxygen on the hemoglobin. Okay.
That's the saturation. Is this hemoglobin molecule saturated with oxygen or no? And lastly, p a o two, which is the partial pressure of oxygen. That's the oxygen free in the plasma. Free.
Okay. This is bound to hemoglobin. This is free. Okay. So what do you think about anemia?
Okay. How do you think anemia will affect every single parameter here? Will anemia affect the free oxygen in the plasma? Absolutely not. So this is normal.
Will anemia decrease the saturation of hemoglobin with oxygen? Absolutely not. The reason why both of them are normal and anemia because your lungs are still working. Okay? They are supplying oxygen.
Oxygen comes here on the hemoglobin. Oxygen floats freely in the blood. No issues. However, the hemoglobin concentration is decreased. Why?
Because anemia has a problem in the total RBC mass and that's include the hemoglobin concentration. So the hemoglobin concentration anemia is really low. So the oxygen content will be decreased. Why? Due to decrease in hemoglobin concentration.
However, both the percent saturation of oxygen and the partial pressure of oxygen are completely normal. This is insanely important to understand. Anemia, saturation, normal. Partial pressure of oxygen, normal. Hemoglobin concentration decreased.
Oxygen content decreased. Clinically, what are the signs and symptoms? By the way, what's the difference between sign and symptom? Okay. Sign is something that the doctor discovers on exam.
Symptom is something that the patient complain of. Okay. So the way to remember it is sign has I. So I and the doctor see it. That's a sign.
Symptom has a y. You as a patient describe it. Okay. Clinically, anemia has tired and pale, pale and tired, fatigue, dismay on exertion, chance of breath when exercise or just on normal activity. Dizziness, inability to concentrate and has flow murmur.
Why is that? So this is imagine that this is the heart and there is a valve. We have two types of murmur. Number one, organic murmur, where there is a problem in the valve, organically in the valve. Okay?
The other type is called flow murmur, which is found in anemia. So in anemia, you have decreased viscosity of the blood. So the blood is very light and it's flowing really fast. When it flows fast from the valve and then hit the wall, okay, of the vessel or of the heart, that creates a murmur. So there is a flow murmur in anemia.
Blood is flowing really fast. How to classify anemia clinically? Now we care about clinically. Okay. So we measure something called the MCV, which will be discussed in a later video.
So MCV, the normal MCV is 80 to a hundred. It's probably 80 to like 96, but I don't care. It's 80 to a hundred. Okay. If it's less than 80, that's a microcytic anemia.
Okay. The blood cells are baby. They are very small. In normalcytic, it has normal MCV, eight to a hundred. This is normalcytic anemia.
Macrocytic anemia will have an MCV of more than 100. One might ask, isn't macrocytic anemia good? No. It's anemia. But my blood cells are big.
However, the total RBC mass is decreased. It's anemia nonetheless. That's an introduction to anemia. We will continue in the next video, but please subscribe to get it. Thank you for watching and see you next time.