Before doctors on TV inject someone they flick the needle is this nessesery and if so why . Does it actually happen in real life
In: Biology
To remove the air. Because an air bubble in your bloodstream can clog small vessel. (As far as I know. Im not in the medical field)
Yes, it happens in real-life, and it is to remove air.
However, it’s a poor way of doing so, and the reason isn’t to prevent death from the air, but to ensure that the drug dose is accurate.
Small bubbles such as those you’d get in a syringe wouldn’t cause harm.
Fun fact: the amount of air (injected directly into the bloodstream and not fat or muscle) it would require to kill you is around 50-75 cc’s depending on your size, because this is about the volume of your left ventricle. If the LV receives nothing but air it will spasm and you’ll go into an abnormal cardiac rhythm like VF and die.
Also, flicking the syringe is really inefficient. If you draw something up quickly and there are a lot of small bubbles in it you should suck in a bit more of an air bubble and rock the needle up and down slowly so that the large bubble collects all the small ones, and then you simply expel the large bubble and you’re all airtight and ready to go.
They’re trying to remove as much air as possible. Flicking the syringe, while upright, forces bubbles to rise to the needle, where they can be easily forced out.
I’m of the old generation of nurses who used to actually sterilize and reuse metal needles and glass syringes. Keep in mind, after washing the articles by hand we then use to sterilizing them in an approved alcohol based disinfectant (much like Barbasol used by barbers to sterilize combs and brushes.) We’d rinse with sterile water and then draw up some air to help flush out any accumulated liquid left behind by the the sterilizing agent. We used to then draw up the medication and pray the glass was dry and didn’t mix with any sterilizing agent still lingering on the inner glass or internal needle at the metal hub. IF it burned when going in, we knew we’d fucked up, but it never killed anybody. I was grateful for the switch to disposable needles.
Removing air bubble before injection remains a quality control method for modern disposable syringes and IV’s. Air bubbles can kill if injected into arteries or veins. It only takes a single bubble to cause a stroke or MI, but in most cases one would have to shoot at least 10- 10 cc of air into an average human body to kill a person. (information per trials I was involved with at a military goat lab back in the 70’s while in training for my degree.) I’ve always wondered why death by lethal injection isn’t done by using plain old room air or chlorine gas (might as well use the principle of air bubbles to save money on lethal injections.
Sign me, very old time nurse.
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