I've also got in touch with an old friend who's working in a path lab, and she's let me know of some further insights into how blood taking methodology can alter results, and, more importantly, how to reduce those alterations! Doctors take these results as gospel truth - but it's important to note - alterations can happen and results can and do vary depending on how it's collected.
THE NEXIVA CANNULA.
What makes it the best cannula to use is its basic function. The needle in this cannula is inserted the same way as a regular cannula - with your forefinger placed on the soft tab in the middle (the wings supported by middle finger and thumb). As you withdraw the needle itself though, you need not pinch the vein down proximal to injection site as blood enters the tube meaning you will not come into contact with the blood or have any blood spurting everywhere.
After you insert you see initial flashback, followed by a second flash which is where you stop threading it.
The amazing thing about this is the needle itself. When you remove it, simple pull back on the tab at the end and it pulls out with a cap on the tip - so needle sticks are COMPLETELY eliminated making it MUCH SAFER for the injector.
Preparing the Patient:
If a heat pack isn't available, fill a glove with hot water and place it on desired spot or run a towel under hot water. I picked up this little trick once in the ward where they didn't have a heat pack so there will always be a way to do this =]
7. Although smaller needles are nicer for the patient - they can alter blood results (very fast flow through the needle can cause haemolysis too!) slightly, and slow down the drawing of blood, making it more likely veins can collapse. Too large though, and it'll not only be more painful, but also more easy to miss. Getting the right balance is key!
Choosing/readying your site:
The cubital fossa is more susceptible to kinks and having the cannula tissue/extravasate, as patients move around at the elbow a lot, . People underestimate the pointiness of the actual plastic cannula and don't realise that it can penetrate the vein from inside if it moves around too much! Unfortunately, in emergency wards, they often attack this vein unnecessarily for cannulation because it's easier to get. In my eyes - it shouldn't happen if a patient is being sent up to a ward or observed - only reserved for "get the cannula in or die" situations.
Going In - keeping the patient calm and getting it right:
With kids in particular, this is vitally important. You cannot lie to them about the pain, as it may lead to involuntary jerks or movement as you inject, but getting their mind off it will definitely help. Again, the trusty glove can be blown up and have a smiley face drawn on it to make it look like a spiky-haired friend. Definitely will cheer up the kids =]
Palpate around the needle to see where the vein is and where you should go if you need to adjust it further. Though painful, in my experience, and from what nurses and doctors have told me, "digging around" for the vein after you've missed is less torturous than having the needle reinserted elsewhere.
13. TAKE THE TORNIQUET OFF AS SOON AS BLOOD IS BEING DRAWN! It's OK to leave it on prior to a patients' blood being taken, but too long can alter results slightly. Ideally, it should be removed/loosened as soon as blood starts being drawn.
Removing the needle:
https://www.facebook.com/musingsofamedstudentpatient <-- If you or a loved one needs help or if you enjoy my blogs or if you're interested in medicine, like my page on facebook =]
Nexiva cannula - more info/reference and details on if they're in your hospital: