Venipuncture STEM content
Anatomy
Physiology
Physiology
Understanding vein wall anatomy, and anatomical structural limits, will define and determine the instructions for venipuncture - locating a vein, dilating a vein, grading a vein, and inserting a needle into that vein. Sir Henry Gray laid this anatomy foundation back in 1894.
ALL structures have structural limits. (ENGINEERING)
Q. What can disturb this structure? A. A forced over distention.
Q. What forces an over distention of this structure?
A. The Tourniquet.
The vein wall consists of three layers of tissue: intima, media and adventitia.
The middle layer, the media, is ALL muscle - smooth muscle - innervated smooth muscle.
Over stretching of this innervated muscle causes:
- Pain
- And can tear the muscle
Physiology
Physiology
Physiology
Back in 1896, Ernest Starling laid the foundation for venous physiology. That science tells us that there is a 'normal' venous pressure for any segment of vein; exceed that 'normal' and Starling's Equilibrium is disturbed.
This results in - leakage / extravasation / INFILTRATION.
Infiltration is a real problem in IVs of fluids and meds and a real problem in the injection of contrast in x-ray procedures.
And INFILTRATION results in HEMOCONCENTRATION in the blood draw - falsely elevated lab results.
What disturbs the venous pressure? An over distention /over filling of the vein.
What causes an over distention / over filling of the vein? The Tourniquet!
We now have 'Starling's disEquilibrium" and all of the CCIF(s) that go with it.
Chemistry
Physiology
Chemistry
There is a new PALPATION technique for locating, dilating, and grading veins that utilizes the chemical 70% Isopropyl Alcohol.
Palpate WET with 70% IPA.
- 70% IPA prevents FRICTION,
- enhancing the sense of touch,
- locating a 'healthy' vein 100% of the time.
This reduces the multiple stick to less than 1% and vein rupture upon venipuncture to less than 2%.
The vein finder tools and the ultrasound machines that hope to visually help locate a vein - still result in a 50% failure rate to locate and access veins.
Locating a Healthy Vein - is ALL about the sense of touch, not sight.
Locate, Dilate, and Grade A Vein by Touch the 21cVA Palpation Technique using 70% Isopropyl Alcohol.
Physics
Engineering
Chemistry
#1 We just learned about preventing FRICTION (grab and drag) when palpating wet with 70% IPA.
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#2 The needle insertion FRICTION grab and drag can also be reduced by changing the angle of needle entry to 45 degrees.
The current 15-30 degree low angle of needle entry creates GRAB and DRAG, requiring, then, a GRIP and SHOVE of the needle to overcome the FRICTION.
By changing that needle angle of entry to 45 degrees, insertion friction is minimized, the needle glides in, and when the wall of the vein is penetrated there is a 'frictionless give' that signals that the needle has penetrated the vein wall and the bevel of the needle is centered in the lumen of the vein (given that the correct gauge needle was selected).
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#3 Using PHYSICS again, we can adjust grip strength on the needle when inserting that needle into the vein. The lighter the grip, the less the patient feels. The lightest grip, the patient feels NOTHING of the insertion. The heaviest grip, the patients feels every 'ounce' or torr of the insertion.
Just ask any serious and skilled golfer about 'gripping the club and the affects on the direction of that golf ball'!
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#4 What does Isaac Newton's GRAVTY have to do with point-of-care (POC) Finger Stick and Infant Heel Stick blood collection?
Where does GRAVITY take EVERYTHING? DOWN. So, why are healthcare workers always pointing the finger or holding the heel UP for these sticks?
By pointing UP, the blood travels DOWN, away from the site. Now it won't bleed. So, the worker has to SQUEEEEZZZEE.
Squeezing causes hemolysis, hemodilution, and a crush injury and, because it doesn't want to bleed, there is usually an insufficient quantity of blood (NSQ). These are some of the CCIF(s).
Result: A compromised sample of blood and a compromised (injured) patient. Not good.
How can Isaac Newton's Gravity be used in our favor? Point the finger or heel DOWN! [The site should face the floor!]
Gravity will take blood to the site. No squeezing necessary.
Result: A non-compromised sample of blood and a non-injured patient.
Engineering
Engineering
Engineering
Where Tools, Technique,
and Science Meet!
Understanding how tools are made and the intended scientific purpose for those tools defines how the tools should be used.
Unfortunately, the scientist who designed the tools are NOT the ones teaching the workers how use the tools. Major disconnect!
Example: Wrong Tool/Wrong Use-The Tourniquet: The tourniquet was DESIGNED to prevent bleeding to death. It never was designed to 'dilate a vein'.
- Bleeding to death occurred from the 5th-19th c bloodletting with a razor or scalpel - that cut a wide swath, sure to hit a vein (and an artery and other things). The tourniquet was correctly used here.
- But in 1853, when the needle was invented, replacing the razor and the scalpel, bleeding to death was no longer a threat. The tourniquet should have been put away. [No Bleeding to death from a needle stick.]
- But because a microscopic point of a needle in search of a vein just got harder, and veins did 'enlarge' with a tourniquet, the 19th-20th century workers continued to use the tourniquet - to 'dilate the vein' - to make it easier to locate the vein. [Side bar: How many multiple stick events still occur with a tourniquet? Obviously, this is not a good method for locating veins!]
When 'treatment bloodletting' became 'diagnostic blood testing' - the tourniquet should have been put away. Starling's Physiology would agree.
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Example: A STEM engineered tool to replace that tourniquet - based upon Starling's Equilibrium -
The veniCuff.
The veniCuff is an inflatable vinyl cuff, with a pressure relief valve, and a BP cuff bulb and tubing - that limits the inflation pressure of the cuff to 20 mm Hg. Per Starling's Equilibrium and calculated antecubital superficial vein pressures, this 20 mm Hg supports the anatomical and physiological vein structure - no over distention.
NO related CCIF(s) with this tool.
Science (STEM) applied. Changes everything.
Math
Engineering
Engineering
Look at the math diagram above comparing angles of entry and area for 15 vs. 45 degrees.
Thinking just plain math - compare the amount of AREA affected by each entry. Clearly there is less area affected by the 45 degree angle of entry.
Now think of a needle entering through a three tissue layer vein wall. Clearly the 45 degree angle minimizes vein wall damage/injury. This will diminish any discomfort, clotting time, and bruising.
And because there is less surface area of the needle dragging on the skin upon insertion, there is less friction grab and drag on the needle, requiring minimal grip strength for the insertion.
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Position of the bevel within the canal: With the low angle entry (15-30 degrees), the bevel of the needle ends up facing UP, facing the anterior internal wall of the vein. When the vacuumed tube starts to suck the blood out, the wall of the vein is sucked into the bevel, corking the flow of blood off - now the worker thinks that the vein has collapsed. It didn't.
With a 45 degree angle of entry, the bevel of the needle is facing the canal of blood, and the vacuumed tube will only suck what the bevel is facing - in this case, blood.
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Another CCIF of low angle needle insertion includes hemolysis.
The bevel of the needle is razor sharp - think of a meat slicer blade. When the bevel is 'flat' (facing up), as the blood is sucked in over that bevel, the RBCs are sliced (cut). This is an hemolysis - splitting of the RBC. This dumps the cells cellular 'guts' out into the serum - falsely elevating serum lab results.
Most blood tests test the serum of the blood. Falsely elevated serum values result in wrong diagnosis. Wrong diagnosis results in wrong treatment.
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Between the serum concentrated blood from the use of the tourniquet and the hemolytic contribution from the low angle needle entry, and the multiple other errors not described here on this webpage - how WRONG are lab serum values?
how many years did bloodletting last?
Make no mistake......
Bloodletting with a Tourniquet, a bowl and a razor/scalpel lasted 1400 years - 5th-19th centuries.
1400 years!!!! The first era of vein access.
Here's why. The first to perform bloodletting were BARBERs. That's where the red and white barber pole came from and what it advertised - bloodletting. [Red for the blood, white for the tourniquet, and the pole was used to squeeze to increase the bleeding.] And, finally, surgeons joined in performing bloodletting, replacing the razor with a scalpel.
Then the 18th Century Scientific Revolution began. And the needle that we use today, invented 1853, replaced the barber's razor and the surgeon's scalpel.
But still, so much of the foundation of bloodletting was brought forward into this next (2nd) era of vein access, like:
- the word 'phlebotomy' which means to surgically cut a vessel with a scalpel, which was true bloodletting;
- the tourniquet - to be used now to 'dilate a vein' to be better able to locate a vein;
- and the 'milking of the hand', like squeezing the pole, to increase bleeding.
Scientists like Sir Henry Gray (Gray's Anatomy - 1858) and Ernest Starling (Starling's Equilibrium 1896) discovered and described their work in Anatomy and Physiology, respectively, but they were in different parts of the world (like Woods and Pravaz with their 1853 needle). Gray and Starling did not have a clue that someone down the road was going to insert that needle into that anatomical vein and disturb that venous system.
And, unfortunately, instead of scientists and highly science educated individuals continuing to research, develop, and perfect this new vein access skill with a needle, this procedure was turned over to the lay person, or the nurse, or the allied health worker, none of whom are surgically trained or STEM educated.
So, this 19th-20th century second era of vein access has continued with wrong tools, wrong techniques, and wrong information - for the last 162 years.
- Recall the CCIF(s) on the home page.
- Recall the number of venipuncture procedures performed each year throughout the USA and the world.
- Recall the statistical occurrence of vein access failure (30-40%).
- Recall the number and types of healthcare workers who have no STEM education and no STEM training on this venipuncture procedure.
And know that these venipuncture / vein access procedures are the technological foundation of Dx (diagnosis) and Tx (treatment) in the Practice of Medicine.
It's time to change.
Bring Phlebotomy Training, IV Training, and Injection of Contrast Training into the 21st century.
IT'S TIME for the.....
3rd Era of Vein Access
21st century
STEM Venipuncture
21cVA Technique
for
ALL
Vein Access
Venipuncture
procedures.