Confused....

if the HGB is low, but the RBC are normal, they may have iron deficiency anemia,

someone with low blood pressure often has increased rr and hr. it could be that they have a decreased fluid volume so the heart is beating extra fast to get the low amount of blood (and oxygen) circulating.

Low oxygen levels aren't mainly related to HgB. It can be. Someone's B/P is low from hypovolemia ( from low HgB count.) And yes, the blood loss can relate to hypoxia but there are other things like COPD, asthma, airway obstruction, etc. The best thing to remember is that respiration is a compensating mechanism. Respirations increase to bring more oxygen to vital organs, however, they start to lose carbon dioxide, which is a baroreceptor. Pulse increases to help move the oxygenated blood throughout the body, but increased pulse rate does not raise your bP, it can actually make the BP go down. When heart is pumping very fast, there is not a good "sqeeze" = lower cardiac output..so the B/P goes down. Instead the nice pump, pump, pump, it quick squeeze, squeeze, squeeze. The resp. try to stay up b/c they are trying to fill the lungs with 02. But if someone has a low HgB, there is not enough volume, and so the BP will low. But some people can low HgB and be fine. Many anemic patients as Ashley stated, do just fine. They have been porbably been living at that level for months, even years. So their bodies have compensated for it, but if they have large volume loss...well then you have replace the volume (hopefully blood trasfusion)...then the pulse will go down b/c it doesn't need to work so hard and the blood pressure will rise b/c there is more pressure and stretch in the vascular system :) Hope that helps

if the HGB is low, but the RBC are normal, they may have iron deficiency anemia,

someone with low blood pressure often has increased rr and hr. it could be that they have a decreased fluid volume so the heart is beating extra fast to get the low amount of blood (and oxygen) circulating.

Sorry I am completley lost here....

I thought that when one had low oxygen (Im assuming low O2 because of the low Hemoglobin) that their BP would be high, which is why when we put one on Oxygen the BP drops.

However this patient (case study) has her hemoglobin drop more post op (95 preop down to 69 post op-RBC are still within normal value), BP further decrease (from 100/60 to 90/60) and Respirations and Pulse are still quite high.

Would the patient have hypertension? And why wouldnt the BP increase as she becomes more O2 deficit? The O2 has decreased as well (fallen from 94% to 92%)...maybe Im overthinking things?

Low oxygen levels aren't mainly related to HgB. It can be. Someone's B/P is low from hypovolemia ( from low HgB count.) And yes, the blood loss can relate to hypoxia but there are other things like COPD, asthma, airway obstruction, etc. The best thing to remember is that respiration is a compensating mechanism. Respirations increase to bring more oxygen to vital organs, however, they start to lose carbon dioxide, which is a baroreceptor. Pulse increases to help move the oxygenated blood throughout the body, but increased pulse rate does not raise your bP, it can actually make the BP go down. When heart is pumping very fast, there is not a good "sqeeze" = lower cardiac output..so the B/P goes down. Instead the nice pump, pump, pump, it quick squeeze, squeeze, squeeze. The resp. try to stay up b/c they are trying to fill the lungs with 02. But if someone has a low HgB, there is not enough volume, and so the BP will low. But some people can low HgB and be fine. Many anemic patients as Ashley stated, do just fine. They have been porbably been living at that level for months, even years. So their bodies have compensated for it, but if they have large volume loss...well then you have replace the volume (hopefully blood trasfusion)...then the pulse will go down b/c it doesn't need to work so hard and the blood pressure will rise b/c there is more pressure and stretch in the vascular system :) Hope that helps

Thanks...reading this and starting to put things together...:)

Well...You have think in terms of compensation, not one thing goes up while the other goes down. If you give oxygen to someone who has a low BP and it goes up, that is b/c of severe hypoxia. Like in a code...Lets say someone becomes bradycardic... 50s, 40s, then 30s...bp is dropping and you are trying to intubate. Once you intubate and re-oxygenate, then the HR and BP will return to normal b/c the O2 is getting back in. But that is for hypoxia. In a normal setting, if someone's BP in low, giving them oxygen isn't gonna do anything unless it's strictly related to hypoxia. Actually, carbon dioxide is more vasoactive than O2. Giving O2 doesn't really do anything for BP (unless they are hypoxic) but CO2 is very potent when elevated. If someone's CO2 level is down, Resp decrease to raise it. If the CO2 level is up, Resp. increase to blow it off. CO2 is the main predictor of how fast or slows someone Resp will be. The O2 doesn't really affect it (unless severely hypoxic.) The body has baroreceptors that react to CO2. CO2 causes vasodilation. If you hyperventilate an intubated patient with elevated intracranial pressures (ICP), then ICP will drop momentarily. If you are in surgery try and get in on a craniotomy. The anesthesiologist will hyperventilate and brain will shrink down right in front of you, which is pretty sweet!

In the example you gave...I'm confused with the 69-95 RBC. Do you mean that's the oxygen saturation? If it was O2 sat, then giving them oxygen will correct it. Plus, in this case, many post-op pts have some volume loss (bleeding). Any volume loss makes the BP decrease and having high HR and Resp is expected. If someone's BP is down, the body compensates by increasing heart rate and resp to bring oxygen to the body and flush out CO2. Like when somone works out...you're running, using up more oxygen, so the HR and Resp increases. Or when someone is severely dehydrated...their HR is elevated... so you give them fluids which makes the HR go back to normal b/c the volume is returning.

Now, i understand the thinking that the BP would increase when the O2 drops to compensate. Maybe, maybe in early stage but as the O2 drops further, the organs start becoming staved and everything starts shutting down. Plus, if you are becoming hypoxic and everything starts vasoconstricing (which means the body is working harder to compensate and using more blood reserve) what's gonna happen to the O2? It's gonna go down further b/c more demand = more O2 consumption. But this pt was post-op (which would include probable volume loss) and giving O2 doesn't make up for volume loss, especially someone who is already anemic. But lets say someone is anemic in everyday life, out in the world, no surgery. Yeah, they could have HTN b/c the body has compensated for the anemia. Maybe their body has held on to sodium or the kidneys has slowed down urine output to compensate for the normal anemic levels (lower volume). But with post-op, the issue of hypoxia and volume loss is different than someone with chronic anemia at home.

So.. does anemia cause low BP? And if so, why?? because of decreased fluid volume? (low HGB)