So tomorrow is trash day I’m cutting up the unbroken boxes from our renters to make room for all of our recyclables. I work in retail and use a box cutter all the time so I’m generally careful (read: extremely careful) with these things. The rule is, “Never pull the blade in a direction you don’t want it to cut.” Well, maybe not extremely careful anymore.
So I goof up and nick myself on my left arm right across one of those 1/8" veins that run along ones forearm. “Nick” is maybe an understatement: 11 mm long by 4mm deep (I measured), straight across one of my vital pipes!
I start applying pressure and paper towels to the wound and, though it bleeds, it all seems to calm down in about fifteen minutes, or so.
Is venous pressure not that life threatening to poke a hole in one? Or was I lucky that the vein was distal and of small diameter?
For what it’s worth the wound is washed up and cleanly dressed.
No doctor here but it’s my understanding that the artery has high pressure, vein much lower pressure and smaller diameter so the vein clots more easily with less blood loss. IIRC the artery is protected by the tendons or something when you hyperextend the wrist.
IANAD (yet, here’s hoping) but generally venous pressure is pretty low. Your body actually needs a couple ‘tricks’ to get all that deoxygenated blood back to the heart - both your skeletal muscles and breathing action serve to force the blue stuff through the interconnected series of tubes. Even then, our bodies use one-way valves to prevent backflow.
I can’t vouch much for the severity of venous injury, although you’ll probably have a killer bruise. Remember also that the veins you can see aren’t necessarily your ‘vital’ pipes as the limbs tend to pair them up - a superficial, visible vessel and deeper ones beneath; they’re used to help temperature regulation.
Thanks all, I am going to call my brother (at work at Disneyland right now), who’s an MD, and pester him. Those veins look like such giant pipes but, eh, maybe aren’t after all.
With normal physiology and no clotting problems, bleeding from a superficial vein is almost always easily controlled with direct pressure and elevation. Venous pressure is low for veins that can be elevated above the level of the heart. Cut a big one down by your ankle and it will bleed nicely if you don’t elevate the foot. Despite the venous valves, which are not particularly robust, the pressure is markedly elevated by the column of blood above (also the reason varicose veins are more common in dependent areas).
Unlike arteries, veins are almost never critical, so if they do bleed you (well, your caregiver, anyway) can just tie 'em off and the blood will reroute just fine. If they stop bleeding and clot up with pressure and a gentle dressing, it’s unusual for further intervention to be required.
Quick question. If you sever one of the visible veins completely and you stop the bleeding with pressure (no suture) will the vein eventually repair itself or will both ends just close up and that particular blood route becomes non-existent from then on. ?
I once asked the person drawing yet another sample the probable consequences if he hit the red tube (artery) instead of the blue one in my elbow: “you could bleed out right here”
which gfets us to:
Just what is “120/80” in PSI? Why don’t we use a common unit of pressure for blood?
It’s in mmHg. I guess if you WANTED to take the PSI, you could just divide the numbers by 51.71… So “normal BP” would be 2.0794PSI/1.5471 PSI :dubious:
But… that’s a pain in the ass. And the measuring devices are already in mmHg…
Plus you want to detect changes as small as several mmHg, which is alot easier to see from a change of 120 to 140 (possibly at risk for Heart issues with certain factors- the first one that popped into my head) than whatever 2.0794 would go to @140mmHg (ETA: Apparently 2.7074 PSI)
As for what the numbers MEAN- I suck at explaining so here’s a link to the definitions:
120 is the Systolic pressure, 80 is the Diastolic Pressure. Basically the maximum pressure during contraction of the heart, and the minimum pressuring relaxation of the heart.
I’m not sure on this one, so I hope someone more qualified than me comes along to answer this, but my guess: if you take a vein and sever it completely (so the two ends are NOT touching even, and you just use pressure to stop the blood flow… I’m gonna go with yeah, that’s not going to just regenerate and find it’s other end so easily.
If you kept the two ends together, but didn’t suture, even then I want to say it’s not going to work, but I’m waaay less sure on that one. But in order for it to regenerate, it’s going to need nutrients and flow, and if that vein is severed completely there’s no blood flow there (since presumably you’re clamping it. So I’d think that the route would just die and HOPEFULLY clot up, and it’s going to be non-existent. But you also added Visible Veins. Which makes me wonder… which vein… because you severe a Jugular and you don’t suture it back together… You’ve got big problems there. Most of the visible larger veins in the arm- sure if you nick it, do the apply pressure thing, and on bigger ones get it looked at and sutured. But if you take one of your bigger upper arm veins and just cut it completely… I think it’s not going to fix itself so easily.
I will gladly defer to someone who knows more than me though on the matter. IANAD.
