Strange A. Fib Event HELP!!!!

[sperry1964]

OK Guys I need your help. I am a nursing Student. We have a patient with A. Fib, CVA w/left sided weakness, COPD. Currently on beta blocker and anticoagulation therapy. We ambulated the patient with pulse ox to check exercise tolerance. She started at 95 O2 sat and pulse of 82. We walked 32 feet and suddenly the monitor is beeping and showing O2 sat of 93 but a pulse of 37. We put the patient back in her wheelchair. She was completely asymptomatic aside from the pulse dropping. She recovered to her usual 65 bpm in less than a minute.

Can anyone tell me why this patient's pulse would drop on excertion?

[HollyHobby]

One of the very first things I learned as an ICU nurse is "look at the patient, not the monitor".

So my first response to your question is: are you really sure her pulse dropped? O2 sat monitors are particularly finicky. They can stop sensing properly if the patient moves her hand, or sometimes for no good reason at all. It may look like it's picking up the O2 sat, but the heart rate could be wrong, or vice versa. On my patients, 99.9% (I'm guessing here) of all pulse ox alarms are false readings.

In order to determine if my O2 sat is "real" or "just pretend", I compare the waveform on the sat monitor with the patient's rhythm on her telemetry, or her waveform on her art line, or whatever else I can see at a glance- especially looking at the patient. (If the sat is saying 40% but the patient is pink and talking, or if the sat says 99% but the patient is blue, I'm not going to trust the monitor.) If the sat monitor doesn't have a good waveform, you probably don't have an accurate sat (or heart rate). I'm assuming that the patient you were ambulating didn't have an art line or tele or whatever, so in that case you should compare the sat monitor pulse reading with her actual pulse, as palpated by you.

I'm willing to bet your sat monitor just wasn't reading properly. However, if it was, I'd go back to the "look at the patient, not the monitor" mantra. A fib presents differently in different people. In some patients, their a fib is so regular that you have to really look to be sure it's a fib. Other people have very irregular a fib: it can speed up super fast and then slow down or even have long pauses just a few seconds later. (Of course beta blockers help with this.)

You said your patient's usual rate is 65. Is it always right around 65, or does it speed up and slow down? Maybe (for the sake of argument, assuming her pulse ox was right) she had a couple of slow beats.

You did the right thing: sat her down and assessed her and came to the conclusion that she was asymptomatic. Some people live with rhythms that are downright ugly, and have no symptoms at all. If this is what's going on in her case, then there's no need to panic. She's getting the right meds and the right treatment.

My suggestion would be to investigate the matter further with other forms of monitoring. For example, put her on telemetry and see if her heart rate really does drop when she ambulates or at other times. If nothing else, when you ambulate her, keep your finger on her pulse while she walks.