How Bleeding Causes Rigidity?

[AnthonyM83]

I've come upon two opposing views on this....so I'll ask The City:

How does abdominal bleeding lead to rigidity? Through what process, exactly?

[Bieber]

I've always assumed it's due to the fact that you have a large volume of fluid in a tight, restrictive compartment. Similar to if you squeeze one end of an IV bag and the fluid moves to the opposing end and causes it to become rigid.

[Paramagic]

Irritation of the peritoneum by free hemoglobin. Rigidity will not necessarily be present depending on the level of free hemoglobin following hemorrhage.

[JPINFV]

Yep... irritation and inflammation. A rigid abdomen is caused by either of those and can be found in conditions other than a bleed. Massive amounts of fluid (e.g. ascities) would be more like a really filled up water balloon where you can induce a fluid wave over the abdomen.

[Bieber]

Good to know! I hadn't ever heard that. I'll have to do some more reading later today.

Thanks, Paramagic and JPINFV.

[zippyRN]

Yep... irritation and inflammation. A rigid abdomen is caused by either of those and can be found in conditions other than a bleed. Massive amounts of fluid (e.g. ascities) would be more like a really filled up water balloon where you can induce a fluid wave over the abdomen.

and someone with bad constipation / bordering on impaction often has a hyper-resonant abdo due to gas trapped in the bowels ...

[AnthonyM83]

Alright, all that's been said sounds good to me.

Another EMS provider (who is usually knowledgeable) was saying that blood was not a chemical irritant to abdominal muscles and did not lead to the peritonitis.

I'm trying to figure out where he was going with that...Didn't have time to clarify with him...

[Dustdevil]

Another factor to consider is what exactly is becoming rigid. Organs? Skin? Fluid? When you break a femur, what happens? Muscle spasm. You strain your back, and what happens? Muscle spasm. Sensing the irritation within the abdominal cavity, the abd musculature would logically tighten up in a protective reflex. If you have bled enough into your abdominal cavity for the sheer volume to cause rigidity, you are probably already dead.

[Paramagic]

Alright, all that's been said sounds good to me.

Another EMS provider (who is usually knowledgeable) was saying that blood was not a chemical irritant to abdominal muscles and did not lead to the peritonitis.

I'm trying to figure out where he was going with that...Didn't have time to clarify with him...

Interesting. It certainly is an irritant when it gets into places where it shouldn't be (like the brain for instance, think of subarachnoid hemorrhage and the fever that often develops)

What did this medic think caused the rigidity?

EDIT: Missed Dustdevil posting, but agree. If volume alone is causing rigidity 1) it won't be true rigidity like we are discussing and 2) that's your entire blood volume plus, well, a hell of a lot. Consider the massive amounts of fluid that can be tapped off someone who has ascites.

Edited April 17, 2011 by Paramagic

[AnthonyM83]

I'll ask him next time I see him. Just trying to arm myself with some info before that