Capillary Tubes: Blood Sample Too Thick?

[JimChicago]

Just a question regarding people's experience with capillary tubes.

This morning when I tried to get a sample to test - the blood drop would not flow into the capilllary tube. So I took another strip out of the fridge - waited an hour and a half and retested and the same thing happened the blood appeared to be too thick or whatever to go into the tube - but this time I was able to drop the sample directly from my finger onto the test strip - the test worked and the result was a 2.8 INR which is about where I've been for a month.

Just wondered if anyone has any idea why the blood seemed too thick to go into the capillary tube - it's a little chilly but probably around 70 in my house so it wasn't frozen. I wondered if I should squeeze the bulb then touch it to the blood sample - let go of the bulb - and thereby try to suck the sample up with a vacuum action instead of just a capillary action?

 

[Guest]

The only one that I know about is CoaguChek. The hematocrit is the percentage of red blood cells in your blood. If your crit gets above 50% the blood will not run up the strip of the CoaguChek. The two main ways that your crit gets too high are:
1. Polycythemia vera - a disease where your body makes too many red blood cells.
2. People who have severe asthma or aare chronic heavy smokers. These people are literally gasping for air. Their tissues are crying for more oxygen so the body keeps making red blood cells to try to provide it. The problem however, is not the red cells, it is that the damaged lungs are not able to provide oxygen.

These are two conditions where the blood is literally too thick. One other possibility for thick blood is severe dehydration.

Aside from those ways, it would be an extreme rarity to have the blood be too thick.

My guess would be something to do with surface tension keeping the blood from going into the tube. I don't use capillary tubes but about once in every 50 tests or so the person's blood will just not go down into the CoaguChek strip. It runs around the hole but will not go down in it. Since the blood is red I think of the Alabama Crimson Tide
Around the bowl
And down the hole
Roll Tide Roll

 

[Ross]

The tube is vented is it not? If your blocking that hole, it's not going to work.

 

[JimChicago]

Thanks Al and Ross -
I almost wonder if it might be that I tested in the morning before I drank hardly any fluids so I might have been leaning toward the dehydrated side like one of the possibilities Al mentioned. Like Ross says it's also possible I squeezed the bulb when collecting the sample and that's why it didn't work.

On my next text I'll wait til evening, drink a couple of glasses of water in advance, and get my capillary tube technique in gear - I hate wasting those test strips.

I have been been not so concerned about dehydration as I had been told to restrict my fluid intake to avoid getting fluid retention/chf again.

Here's one anecdotal comment on thick blood on the interent -

From:
http://www.cbass.com/Water.htm
>>>>
It?s especially important to drink some water at bedtime because, according to Dr. Kensey, heart attacks often occur in the morning when we are dehydrated and our blood is thicker than during the day.
>>>>

 

[azpam]

to get a good sample, always drink a glass of water half hour or so before hand. run hand over warm water,and keep arm/hand dangling down. if you do all that, you should not have to "pump" your finger before sticking it.the blood should be there already.

 

[JimChicago]

Thanks for the advice Azpam - I'll fill 'er up with a glass of water first as you suggest from now on.

 

[JimChicago]

I found an interesting article on the water hydration issue - which suggests being adequately hydrated helps to avoid heart attacks also -

From:
http://www.llu.edu/news/scope/spr02/water.html
>>>>
Coffee, soda, milk, and caffeinated sodas did not show any statistically significant heart benefits. Most other fluids are considered high energy drinks. The initial effect of these types of fluids is actually to draw water from the blood because they cannot be digested until their concentration is reduced to be similar to that of blood. This causes at least a temporary increase in blood viscosity, thus increasing the risk of blood clots.

Water, however, is absorbed immediately, thus hydrating the blood system. Drinking high amounts of water then thins the blood, reducing the risk of blood clotting, which could lead to heart attacks.

?People need to be made aware that there is a difference, at least for heart health, whether they get their fluids from plain water or from sodas,? says Dr. Chan.

Though more research is needed to confirm the findings, Drs. Chan and Knutsen have already adjusted the figures to account for other potential factors in heart disease fatalities such as age, smoking, calorie intake, exercise, blood pressure, and socioeconomic status.
>>>>

I guess the trick is finding the optimun amount of water intake - not so high as to require lasix but not so low as to be dehydrated.

 

[Marty]

I think Ross is on the right track. The rubber bulb on the end of the tube must have a hole in it and the hole must be open or their will be be no draw.