hemorrhage vitals signs

[ashleyann0207]

during a hemorrhage, what exactly are the basic vital sign changes? i know that bp drops, pulse and respirations increase, but what exactly does temperature do? does it decrease also due to decrease in blood flow?

[Kuriin, BSN, RN]

What do you think will happen to your WBC and H&H?

[HouTx, BSN, MSN, EdD]

Hmm - let's steer into some critical thinking.

As intra-vascular volume drops, peripheral vessels squeeze down, shunting blood to central/larger vessels in an effort to preserve vital functions (brain, heart, lungs). The heart rate increase is triggered by 1) baro-receptors that sense a decrease in pressure and 2) chemo-receptors that sense changes in oxygenation. Increased respiration triggered by pH changes (decreased peripheral circulation) and decreased Oxygen.

When those peripheral vessels close down (increased peripheral vascular resistance), what effect does this have on to the extremities & skin surface?

So - how would this be reflected in each of the different places that you could measure temperature? If a patient is breathing very rapidly, how would this affect oral temperature readings?

So, IF all the changes were triggered by blood loss and you could measure the actual temperature of the core of the body - why would it be any different?

[nurseprnRN, BSN, RN]

What do you think will happen to your WBC and H&H?

Trick question. The answer is: Exactly nothing...unless/until the missing blood is replaced by fluids that don't have blood cells in them.

Hematocrit is a %age measure of how much of the blood volume is RBCs. You can bleed out half of your blood volume on the street and when they carry you into the ER and check your Hct it will be exactly the same as it was before you got stabbed and you lost all that blood, though your BP will be low and your pulse high. After they replace your missing volume with a few liters of NS, then it will be lower (though your pulse and BP should be a lot better), because your remaining RBCs will be floating in NS ("dilutional").

The important thing to remember about this is that since RBCs carry oxygen, you could have identical SpO2s in two people, but the one with a Hct of 40 is carrying twice the volume of oxygen to his cells than the one with a Hct of 20.

Dehydration, saline loss, will make you hypotensive and tachycardic, but your Hct will be elevated.

[nurseprnRN, BSN, RN]

Hmm - let's steer into some critical thinking.

As intra-vascular volume drops, peripheral vessels squeeze down, shunting blood to central/larger vessels in an effort to preserve vital functions (brain, heart, lungs). The heart rate increase is triggered by 1) baro-receptors that sense a decrease in pressure and 2) chemo-receptors that sense changes in oxygenation. Increased respiration triggered by pH changes (decreased peripheral circulation) and decreased Oxygen.

When those peripheral vessels close down (increased peripheral vascular resistance), what effect does this have on to the extremities & skin surface?

So - how would this be reflected in each of the different places that you could measure temperature? If a patient is breathing very rapidly, how would this affect oral temperature readings?

So, IF all the changes were triggered by blood loss and you could measure the actual temperature of the core of the body - why would it be any different?

Oooh! I actually did my thesis on that, the comparison between pulmonary artery blood temp and oral/axillary/rectal temps, and about every five years or so I get to apply it somehow!

Short answer is that rapid ventilation (whether from hypercarbia, hypoxia per se, or cellular anoxia > lactic acid production) will, in fact, cool your PA temps some from evaporation especially if the pt is breathing cold dry gases (like air-conditioned air or O2 right out of the wall), but probably not clinically significant due to the central shunting HouTx describes so well.

And if you are worried about evaporative cooling in the mouth giving you an artificially low oral temp, if you can have the patient keep his mouth shut and you have that electronic (fast-reading) probe deeply under his tongue where that big artery that just left his heart lives, the difference will not be clinically significant. Studies have shown that drinking hot or cold liquids and smoking do not significantly change oral temp if you give it a minute to equilibrate and have the mouth closed when you put the probe in.

Whee!