bp in heart failure

[samjoe]

Hi...was just wandering why a lower bp is prefered in heart failure?

[psu_213, BSN, RN]

Think of it this way....in most cases of heart failure what is the problem vis-a-vis the heart as a pump? Also, what is BP--how does it relate to the workload of the heart? If the BP is made lower, what does this mean for the amount of work that the heart is required to do? How is this advantageous for a heart that isn't working so well?

(Hope that didn't confuse you. Share your thoughts and we can go from there.)

[blucrna]

I like that psu is trying to make you think. Simply put, lower bp (but not hypotension) is desirable because the heart doesn't have to work as hard to drive bp. This in turn decreases cardiac oxygen requirements. The lower o2 requirement helps combat angina as well.

Adding to the pursuit of knowledge, what class of medications is usually prescribed to block the maladaptive compensatory mechanism seen in heart failure?

[samjoe]

Thanks for the help :) how would you assess whether a patient in heart failure needed dobutamine? Would this be looking at bp and blood results? For example renal function?

[samjoe]

Im finding it very confusing on deciding whether to give a patient IV diuretics and ace inhibitors when there bp is lower...im used to worrying when a pt bp was below a 100 systolic but this is quite normal in a heart failure patient...getting used to different observation parameters is proving to be challenging. At what systolic reading would you start to worry in heart failure ( what would you class as hypotensive)

[HouTx, BSN, MSN, EdD]

It's not that simple. When it comes to your cardiac failure patient, there's no one-size-fits-all, you have to take your clues from how he's functioning. Limbs all nice and warm? Nailbeds pink? Mentation good? Urine output OK? Lungs w/o rales? Then cardiac output is OK for him, even if systolic is 90. You may have another patient that is looking 'shocky' with a systolic of 110... because there's too much fluid on board. That's why your assessment skills have to be top notch. Just remember, ALL cardiac patients are really multi-system patients because of all the interrelated physiology.

If you ever have a question about which parameter(s) are most important for your patient, discuss it and clarify with the cardiologist - but be prepared for a potentially looooooonnnnnggggg lecture (with badly drawn pictures). They love to teach when they realize that you're trying to learn and improve your own competency.

[KBICU]

Im finding it very confusing on deciding whether to give a patient IV diuretics and ace inhibitors when there bp is lower...im used to worrying when a pt bp was below a 100 systolic but this is quite normal in a heart failure patient...getting used to different observation parameters is proving to be challenging. At what systolic reading would you start to worry in heart failure ( what would you class as hypotensive)

What is confusing you specifically? If a patient is fluid overloaded, diuretics are prescribed to help rid the body of excess fluid. Aces work with the kidneys to control BP. Looking at a patients BNP (or ProBNP, although falsely elevated w kidney disease) clues you in to how much fluid they have on board. If I had a SBP of 95-100 or less (depending on how the pts BP normally runs) id question ACE and diuretic administration. Some parameters say hold med for SBP 90. Obvious side effects are the heart working a bit harder, but monitoring parameters are tight with these inotropes. By removing fluid from the body the heart doesnt have as much "stuff" to pump allowing it to pump more effectively. Dopamine enhances this pump, although if their EF is 15%, you could be just beating a dead horse.

[Esme12, ASN, BSN, RN]

Im finding it very confusing on deciding whether to give a patient IV diuretics and ace inhibitors when there bp is lower...im used to worrying when a pt bp was below a 100 systolic but this is quite normal in a heart failure patient...getting used to different observation parameters is proving to be challenging. At what systolic reading would you start to worry in heart failure ( what would you class as hypotensive)

It depends on the patient.......some patients failure is so severe that even in the presence of hypotension they need the diuresis and the ACE inhibitor, and other drugs, for pre-load/after load reduction. ON a transplant unit I worked the PA pressure were always higher than the systemic B/P...we gave the meds for they needed them to stay failure maintained.....if they didn't get the Lisinopril or Capoten ....the would deteriorate quickly. This will be a patient by patient basis.....check with he MD's and your charge/preceptor.

Do you have a preceptor? I don't know if I have given this to you in the past......You will find this helpful......icufaqs.org

[surferbettycrocker]

ACEs and ARBs arent necessarily simply to control 'blood pressure' for HF patients per se sure the pills can reduce afterload but that's not primarily what these medications are 'good for'in HF. I would think a SBP of 90-100 is pretty good depending on how advanced the HF is. Another good question is it new hf? diastolic HF? systolic? sometimes with HF diuresing with low SBP leads to improved bp by getting rid of extra fluid. As another poster said it is very individualized.

the question about blood pressure-this depends if it is a long time really low EF % patient i would look twice a bp in the low 80's depending on what the baseline is. but i would start to concern myself with a blood pressure in the 70's systolic really. then we get into MAP's and issues with perfusion although....i have seen people 'who live in the high 70's from time to time...likely not for long with maps in the terlet but i digress. long story short--ask opinions of others on your floor who have been at this a long time. then confirm with the 'doctor' what to do about diuretics and ace's.