You might be missing the bigger picture here. Consider the variables that affect your BP:

1. Preload (volume present in the ventricles prior to systole - think of it as the
amount of volume available for the heart to push out)
2. Afterload (resistance the left ventricle has to overcome to pump blood to the body)
3. Contractility (the strength of ventricular contraction - stronger squeeze = better cardiac output)

Look at these three areas for an answer. Since your patient had a screw placed in the femur, I am assuming a femur fracture was present. How much bleeding was there before surgery? What was the EBL intraop? How much fluid resuscitation was given post-op? You may be dealing with a pre-load issue here. Elderly patients who are hypovolemic will sometimes develop A-fib due to the decreased volume (less ability to deliver oxygen to the body, including the heart). If she has chronic A-fib, than this is probably less of an issue. The presence of beta blockers can further complicate your situation by reducing myocardial contractility, reducing her cardiac output. Cardiac output is calculated by multiplying the stroke volume (amount of blood ejected from the left ventricle with each beat) x the heart rate. If your patient has decreased preload and therefore a lower stroke volume, the heart attempts to compensate by increasing the heart rate. This will increase the cardiac output. This situation may explain why your patient's BP improved as the HR went up. Not knowing anything else about your patient and judging by the history presented, I would venture to say she needed more volume. This would increase preload for the heart and also optimize Starling's law with her left ventricle. Some fluid boluses would have probably helped out and improved the BP. One thing you did not include in this scenario was her urine output. That would also be another indicator of how well your patient was resuscitated post-op. Of course, all these numbers mean nothing compared to how your patient tolerates the low BP. Was she A&O x 3 or was she disoriented? Did she have clear lung sounds or were there crackles in the bases? Did your patient have warm skin or was she cold and clammy? Those assessments will let you know if that BP is an emergency or being tolerated. It's the classic "treat the patient, not the monitor" situation.
As for the situation with calcium channel blockers, remember that there are three separate sub-classes of these drugs (benzothiazepenes, phenylalkylamines, and dihydropyridines). Cardizem belongs to the benzothiazepines, which causes vasodilation and also has cardiac depressent effects similar to beta-blockers. I would say that your desire to hold the metoprolol in the face of hypotension and the patient being on a Cardizem drip was a good one. Further reduction or myocardial contractility in the presence of possible hypovolemia and an existing EF of 40% would not be optimal for this patient. I hope this helps you get closer to the answers you are looking for. Cheers!

Pt had scant crackles in bases, but sats fine (97 to 99 percent), and no SOB. Lung assessment hadn't really changed since being there, and she had been on her back for a few days.

EBL- can't remember the number, but it was hardly worth mentioning.

As far as CHF, no echo had been done currently in our facility while I had her. I believe she had a previous EF of 60 percent.

Pt was warm and dry.

I am guessing that she was volume depleted, her urine output was OKAY, but for someone on NS 100/hr, I wasn't impressed with the output. Which reminds me, one of the reasons why I was concerned about killing her blood pressure is because I wasn't wanting to kill her kidney perfussion. I don't recall her labs exciting me much either. I believe her Cr was up a wee bit.

It's hard to convey everything without the chart in front of me ;0), but I did solicit for some food for thought.

I did not call the physician (I'm not afraid to, but I'm a night shifter and like to call only when I really need to).

FST6 and others, thanks for your thoughts.

I'm not a huge fan of Dilt. I haven't been in the ICU for a long time but I have yet to see it actually do it's job. I prefer Amiodarone, just personal preferance I guess. We follow MAP's, (Mean arterial pressures) more than actual BP's for the most part. Anything > 60, even with a sbp 80-90, if the map is > 60 organs are still being perfused. I def. would have held the lopressor, I just had a very similar situation my pt.s bp dropping but she was having a great time with her PCA. Was you pt getting pain meds? They can significantly decrease bp.

Dilt is BETTER than Amio for rate control. I'm a huge fan of amio, but if the pt has chronic a-fib, Dilt is probably better because you're looking for rate control rather than conversion. Hypotension is also an issue with IV amio, so it doesnt necessarily make it favorable to Dilt when worrying about rate control in any hypotensive patient...

I've seen trauma patients drop their H/H 1-1.5 grams 48 hours after fracturing a long bone. It was a dramatic drop from one AM lab to the the next. Don't forget you were fluid resusitating her, so there would be some hemodilution there too.

I would have suggested decreasing and
changing her lopressor to IV q 4 hours for better control. In my experience, cardizem doesn't affect BP as much as lopressor.

Many doctors will write to hold for a pressure <90 and others <100. I personally would not have held the Lopressor. I would have hoped that he would have converted too SR and his B/P would have increased with the slower heart rate and atrial kick. It sounded like the pt was well hydrated too.
Was he in pain? Just another thing to thing about being post op. I would also think about fat emboli if he had those symptoms PLUS SOB.

To be honest with you, I think I would have looked to treat the cause of the rate- despite the AFib, the pt had a lot of other potential reasons to be tachycardic and hypotensive. Was it anesthesia effect causing the low bp? Pain or fever causing the increased HR? At the beginning of your shift, when her pressure was in the 80's, I probably would have shut the cardizem off to see what happened. It doesn't sound like it was helping much anyway, and then maybe she would have been able to tolerate the beta blocker. When it comes to the lopressor- with a BP in the 80's I definitely would have held it- but if she sustained in the mid 90's I would have given it. It depends on other things- what were her lungs like? Was she in some CHF because of the NS at 100 for 2 days, plus the Afib on top of it? Maybe she needed lasix. Was she dry from being in the OR and needed MORE fluid? How was her urine output? o2 sats? I would need all of this info before I could make my decision. I think you have a lot of factors at play here and can't make a prudent decision based on BP and HR alone.

That said, if her lungs sounded ok and her sat was good and she was making good urine, was pain free and afebrile, I really would have liked to have gotten that lopressor into her. Good job, though, it's never a black and white decision.

Ill be honest, I dont work in CCU, but I do have some tele experience. One thing that is an issue is fear of doctors at night. Its our patients lives that are in our hands and if you have a clinical question like... do I hold this medication without peremiters in the face of this.... and you act on your medical interpretation of the reason why you would hold said medication, you are practicing medicine and not nursing.

I would of called the MD. Reason is this...

If something had of happened to this patient and it went to court, a lawyer would of asked... Why did you hold the metoprolol? Did you have guidlines set to hold that medication?

If you held it, and the answer was you had no guidlines... then his next question would be what md school did you graduate from to dictate medical decisions without perimiters.

An answer of, I didnt want to wake the doctor because I was scared... will not cut it.

You do ask a good question, but honestly the bigger picture is that you work at a facility where you feel fearful to call a doctor about witholding a cardiac medication on an icu floor.

I would of called the doctor, asked if he wanted an additional bolus of fluid, and asked if he wanted me to hold the metoprolol. Then again I dont know if this blood pressure is her baseline and when her last pain medication was.

ah sorry just read that wrong that you werent scared. my bad

In my opinion, I would've given the Metop despite the Soft BP in the mid-90's, Metop in my experience contains more of a rate controlling beta effect than a BP changer. Don't get me wrong, Metop can drop a pressure, but no too terribly low. Remember, it's always a PIA looking at past scenirios and having them audited by others.

I currently work in a CCU, mainly with severe HF patients and pre-transplant work-ups. Some Cardiologist prefer a nice pressure in the low 80's (SBP), decreased afterload, blah blah blah...that's another issue.

Of course you have so many variables, but before holding any med, I would be sure to consult with the physician. There is always a method to their madness, generally speaking. Have a great holiday!