Chronic Venous Insufficiency: Definition and Etiology (Nursing)

00:01 Hi, I'm Professor Lawes. In this portion of our video series is going to be on Chronic Venous Insufficiency.

00:08 So we're just going to do another quick review of what those vessels look like.

00:12 Now look at these veins. We'll show you the layers there, right, you have the endothelium. Then you have the basal membrane.

00:20 Next, you have the media, and finally the adventitia.

00:24 Now, keep in mind, we're looking at the layers of this vessel in this series is on veins.

00:32 Take a look at the images we have up for you there.

00:34 One is a normal vein. The other not so much.

00:38 That's a varicose vein. So you can see the differences between the normal vein and the varicose vein.

00:44 The normal vein has a shape that allows blood to flow in an organized way and with little friction.

00:50 Varicose veins on the other hand, one of their main characteristics is that they have this more twisted or called torturous and enlarged shape.

01:00 You can see why from the image.

01:02 Now, because of this twisted and weird shape, this makes the blood flow in adequate with more friction so it's not draining as well.

01:11 So varicose veins are ineffective and draining the blood that reaches for example, your feet.

01:18 And this is what causes people who suffer from this condition after a long day of work to present with lower limb edema.

01:27 So what's the definition of chronic venous insufficiency? Well, chronic venous insufficiency is the name given to this whole group of disorders that is basically characterized by this one thing.

01:39 It's characterized by venous dilation and some abnormalities with the function in the lower extremities.

01:47 So chronic venous insufficiency, it's got venous dilation and/or some abnormal vein function in the lower extremities.

01:58 Now, this happens more often in females than it does in males.

02:03 Yea, us lifetime incidence about 40% of women will develop these up to 17% of men.

02:10 And of course this is something that increases with the client's age.

02:15 Now, regarding etiology, the main cause of chronic venous insufficiency is chronic venous hypertension.

02:22 This chronic venous hypertension can be caused by the DVT, reflux, or valvular insufficiency.

02:30 Okay, so think of those three things.

02:32 Deep vein thrombosis, reflux or retrograde venous blood flow, valvular insufficiency.

02:40 So, you break that into other categories, you think about causes of venous hypertension, what causes the pressure inside those veins to be higher, because remember, we're measuring pressure in the vessels.

02:52 It's the pressure of that fluid, that volume.

02:55 pushing against the walls of the vein.

02:58 So, if you have an obstruction, like a DVT, first group, if you have an obstruction, that pressure is going to be higher.

03:06 The next one's a little harder to keep in mind, but stick with me you'll get this.

03:11 Reflux or Retrograde. That's when blood flow is not going in the direction it's supposed to.

03:16 Usually, this is because of valvular insufficiency.

03:19 So, if you're going to be thinking, what are the main ways that someone can develop chronic venous insufficiency? they've either got some type of blockage in the veins in their leg, or the blood is not going in the right direction.

03:35 And the most common cause of that is going to be valves.

03:38 Remember valves, whether they're in your heart, your veins, your arteries are meant to keep flowing, the blood flowing in one direction. It should be a one way ride.

03:50 In chronic venous insufficiency, there's both primary disease and secondary disease.

03:56 Now, think back to the potential causes and these definitions will make sense.

04:01 So, primary disease means there's the symptoms are present but there wasn't any particular event or precipitating event that happened.

04:09 This is what you see in about 70% of the cases.

04:12 Secondary disease mean it develops after some type of obstruction, most likely something like a DVT.

04:19 And that's in about a third of the cases.