Transcription
Hello again. This is a series on anemia, and in the previous video, we introduced normocytic anemia. And you remember the three main causes: yes, acute blood loss, under production, or over destruction. And as you see here, acute blood loss can be due to automobile collision or motor vehicle accident; they are kind of the same. I'm sure you have memorized this by now. MCV determines the type of anemia: is it microcytic, normocytic, or macrocytic? In normocytic, the MCV is between eighty to one hundred. This slide was in the previous video. What are the causes of normocytic anemia where the MCV is eighty to one hundred? You have acute blood loss, under production, or over destruction. So we will talk about blood loss today, not just the acute one but also the chronic one. Please be aware of the fact that iron deficiency is a cause of under production and can lead to normocytic anemia. We will discuss this soon.
Okay, so here is the story. Morning Glory, blood loss can be either acute or chronic. Acute blood loss can be variable but has to be more than twenty percent of blood loss to have like severe symptoms. What are the severe symptoms? Hypovolemic shock, rather than anemia. So here are the causes: trauma or a motor vehicle accident; those are the main ones. Okay, so hypovolemic shock is the big thing. What happens in hypovolemic shock? You start losing blood, okay, drops of blood, so you're losing blood; you're losing both plasma as well as RBCs. What will happen? Some fluids will come from the interstitial to replace the plasma, and then, and only then, will you start to get symptoms of anemia. Why is that? This is dilutional anemia. Okay, so you are diluting the RBCs because you're bringing in plasma without RBCs. So the RBCs that are left in the blood vessel are getting diluted. Fine. So I'm sort of having any which type of anemia? This is normocytic anemia; that's fine. As a response, the kidney will secrete more EPO; it will try to stimulate the bone marrow to produce more RBCs, and of course, reticulocytosis will occur, but it will take time, around five to seven days, until this reticulocyte is evident. This is the first type of blood loss, the acute one. What will happen? Hypovolemic shock, then normocytic anemia. Okay, how about the second one, chronic blood loss? Many causes, such as GI tract bleeding, peptic ulcer disease, colon cancer, piles, aka hemorrhoids, female genital tract, menorrhagia, and metrorrhagia. What's the difference? Menorrhagia is heavy menses, but it happens during the menses, so during the menses phase of the menstrual cycle where there is the actual bleeding, it's very heavy, okay, a lot of bleeding. Metrorrhagia: metrorrhagia is bleeding in between the menses, in between menstruation. So metro is inter; metro is inter-menses or inter-menstruation; so in between the cycles, in between the menses, this is the metrorrhagia. And of course, cancer can lead to bleeding. This is iron deficiency anemia, and as you all know, iron deficiency anemia starts as normocytic but eventually can become microcytic. If you remember my video on RDW, I made it clear it takes time until you get depleted of iron. So chronic blood loss is iron deficiency anemia, which will start normocytic and then becomes microcytic. In brief, blood loss can lead to hypovolemic shock, yes; normocytic anemia, yes; microcytic anemia, depending on acute or chronic and which phase you're in. And that was it. But how to treat blood loss? Let's see.
So this is a very complicated topic, but for now, I'll try to make it like simple and classy. So acute blood loss: when you have more than twenty percent blood volume loss, think ABC: airway, breathing, circulation. You have to make sure they are okay. You give oxygen, of course, IV fluids, and you may need blood. We should expect the hematocrit to rise to thirty or more; that's fine. How about chronic blood loss? Treat the underlying cause. If you have cancer or peptic ulcer disease, no matter what you do, you still have a disease. Try to treat the underlying condition first. You can give iron, of course, because there's iron deficiency anemia. That was it: blood loss and its relation to anemia. In the next video, we'll continue discussing the different causes and conditions of normocytic anemia. I'll see you then. Take care.