Pins and needles?

After sleeping on one's hand for example, numbness sets in - followed by intense pins and needles as the cells can't get the oxygen they need: How long can it stay without flowing blood before the hand will be paralysed? I've heard that even a few seconds without oxygen (flowing blood) will cause the cells die, but surely it's got to be more like several hours (or even days)?
Answer:
In surgery the general rule is the arm can go without oxygen for 60 minutes and the leg without for 90 minutes to avoid permanent damage. If more time than that is needed, the tourniquet is released for 15 minutes before it is applied again.

In my own experience with foot surgery, it will become very painful for the patient around 45-60 minutes, creating problems for the anesthesiologist. (for most simple foot surgery (where you don't use the leg bones or re-route tendons) many surgeons and anesthesiologists will only have the patient heavily sedated only long enough to do give local anesthesia, then provide only light or no anesthesia after that.)

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I know that the misuse of a tourniquet can cause immediate permanent damage up to and including loss of an appendage or limb. I think it is probably pretty quick if the blood is completely blocked. Needles and pins is only an indication of reduced blood flow and oxygenation. I think complete deprivation is severe pain until the cells die. But what do I know? Not much, really.

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As soon as you lose all sensation in your hand, that is when you will find that it is paralysed.

I would say that this will occur in about 10 minutes after siesation of blood flow.

However, if you were to cut off the blood supply for long enough, it would become paralysed for much longer after blood flow returns, maybe perminantly.

This is why you should always to try to sleep in a good position.

You are at risk of developing DVT (Deep vien thrombosis) because the blood will become stagnant and will stick together. It can block arties, including your heart arteries and blood vessels going towards the brain, leading to death.;
It is a common problems in low cost airlines because people stay cramped for so long,

You should try to move around if you can.

Although pins and needles is unlikily to kill you, it has the potensial to.

CREED

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actually the feeling of intense pins and needles is due to the collapse and refill and it's created by nerve endings along the circulatory system. As far as how long, well some orthopedic cases require the help of a tourniquet up to 30 minutes. prolonged stop of flow will lead to severe ischemia followed by necrosis or cellular death.

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