Last night at two in the morning I woke to find someone had grafted a zombie arm to my left shoulder. I commanded it to move—no response. I jabbed it with my right hand—no response. I threw it against the wall—no response. Would this limb remain forever zombific? Medical literature is conflicted.
The current guidelines for tourniquet use suggest a one-hour maximum for restricted blood flow to upper extremities and a two-hour maximum for lower extremities, but also admit that the onset and degree of tissue death (necrosis) varies according to patient age and physical condition. Past these thresholds, restricted blood flow can result in nerve damage. (The tingling you feel is your nerves’ way of expressing angst—a call to roll over before they get really pissed.)
After four hours without blood flow, wet gangrene and the decomposition of tissue due to stagnant blood trapped in extremities can begin. Generally, your arm will not fall off due to gangrene (as might a finger or a toe); rather, if you allow the infection to progress (the timing of which varies widely), you will be forced to have the arm amputated rather than allowing the infection to become systemic. If not, you will die. Though, this is unlikely to happen to even the soundest sleepers.
The short answer: It’s not good to restrict blood flow for more than about an hour and a half; it’s very, very bad to restrict flow for more than four hours.
I expect comments thanking me for the following illustrative image.
Join me every Monday morning for more grandtastic goodies from The Geeks' Guide to World Domination. Or if you like your geekery delivered fresh, consider subscribing to my rss feed or joining my Facebook Fan Page.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Why Do Spacecraft Like ESA's Schiaperelli Crash On Mars So Easily?
- BPA-Free, With Regrets
- A Dimuon Particle At 30 GeV In ALEPH ??
- New President - Pivot To Moon On Way To Mars? Lunar Spelunking & Science Surprises
- President Obama, Why Humans On Mars Right Now Are Bad For Science
- Biofuels Are A Climate Mistake
- Who Is Trying To Destroy The Internet?
- "For years I've been telling a friend of mine who is diabetic to stop drinking diet soda. He starts..."
- "Instead of the original article - the comments of Chandra Kant Raju are here..."
- "Good points indeed. But I think what the ESA did this time is unusual, so unusual, I don't think..."
- "I agree with most of what you say, but I don't think it's accurate to say that there isn't a statistically..."
- "Oh, you mean things like this?Sunset photo by Tom Hall.That's just the thing I explained above..."
- Pollution Is Many Things - Expensive Is Not One Of Them
- Necrotizing Fasciitis: A Profound Mystery in Medical Microbiology
- Early Math Classes Biased Against Girls, Affecting Career Choices, Study Finds
- Sucralose Study Ripe for Scare-Mongering
- Is Modern Feminism Incompatible with Science?
- When All Else Fails, Bribing Kids to Eat Better