Orthostatic Vital Signs
This discussion at Girlvet's reminded me of how I used to explain the interpretation of orthostatic vital signs to my medical students and residents.
Why do we obtain orthostatic vital signs? In a dizzy patient, we want to see if their current hemodynamic status accounts for their dizziness. In elderly patients or other patients we suspect of having neurogenic orthostasis, the evaluation of orthostatic vital signs allows us to measure their hemodynamic response to standing. In dehydrated patients, we want to see if they have been adequately rehydrated. Of course, many medications may blunt the orthostatic changes in vital signs, but important information can still be gathered by their measurement.
Classically, we were taught that a drop in systolic BP by more than 20 points and/or an increase in pulse rate of more than 20 beats per minute after a change from supine to standing suggested an abnormal hemodynamic status. If there is only a pulse increase but no drop in blood pressure, the test is less significant. If there is a drop in blood pressure without an increase in pulse, one should consider whether medications might be contributing to this pattern.
In the elderly patient, abnormal orthostatic VS in the absence of dehydration may not be affected much by the administration of fluids due to underlying disturbances in blood pressure regulation, and alternate therapies may be more appropriate if the patient is symptomatic.
In the dehydrated patient, the presence of orthostasis, particularly when symptomatic, suggests inadequate rehydration. Orthostasis can also be an important early sign of occult GI bleeding.
If an abnormality in orthostatic vital signs is discovered, the significance must be placed into context. The greater the change in orthostatic vital signs, the more likely there is a problem that needs to be addressed.
Despite modern medicine's overreliance upon blood tests or radiographic imaging studies for the diagnosis of various maladies, the measurement of orthostatic vital signs is quick, cheap, easy, and still valuable after all these years.
posted by scalpel at 4:39 PM
21 Comments:
Oh no! I must disagree! My contrary view:
The sensitivity and specificity of postural vital signs are terrible -- I'm too tired to look it up, but they approximate 75% each, lower in the elderly. Which means that (absent postural symptoms) PVS give you no useful information, either positive or negative.
Further, they take about five to ten minutes of valuable nursing time, and pose some risk to patients. In our ER, I can recall two episodes of patients falling during PVS (one broke a hip). Sure, it's a small risk, but it is real and measurable.
So why on earth would you perform a test that does not give you useful information, wastes your staff's time, and exposes a patient to risk?
Interesting. I'd never had problems with any of that until a med onc put me on an insanely high dose of Ifosfamide. Then, no matter how careful I ws getting up, I'd still pass out.
Do you know anything about orthostatic bps in...anorexics? They were always *obsessed* with my ortho bp in treatment; and, yeah, I was usually orthostatic. (Passed out a couple of times whilst standing up.)
My "normal" bp runs normal on the systolic but low on dystolic. And I'm chronically tachy. So it averages around 100/40 with an average heart rate of around 120 bpm.
I think that in selected cases, the information is useful whether positive or negative. The procedure doesn't have to take any extra time if you multitask properly.
During your history, just press the automatic BP button...the machine will automatically record the pulse and BP. While you are getting the truly insensitive and nonspecific family history or waiting for the family member to dig out the medications from the bottom of the purse, have the patient stand up and press the button again while you listen to his lungs. Done.
It doesn't have to be done by a nurse; a tech can check orthostatics just as well. And you don't just have to stand there in a trance wasting time while you wait. You can be giving discharge instructions or explaining some of the test results at the same time.
And just because some people occasionally do it wrong and let the patient fall down doesn't mean that it's risky to perform.
You can be a successful ER doc without ever doing orthostatics, just like I know several successful ER docs who never review the old medical records (a task that is also time-consuming and often fruitless). But a superior physician uses all the arrows in his quiver.
Sorry Scalpel, I gotta side with Shadowfax on this one. It's an unhelpful, time-consuming test. I do my best to differentiate orthostasis from other forms of dizziness by history and exam, and proceed from there. To me, not an arrow even worth carrying around.
That's PART of the exam for dizziness, and if you aren't doing it, you're just cutting corners. At the very least, you need to get a dizzy patient out of bed and see how they walk. It doesn't have to add any time to check their VS a minute or so after they stand up.
No biggie, we cut corners all the time. It just depends where you choose to cut them.
Do you test for reflexes? Sensory exam (with hot/cold, two point discrimination, etc.)? Do you actually do the Kernig's and Brudinski tests (or however it's spelled)? I do reflexes sometimes, but it never ever changes my management.
You can be a successful ER doc without ever doing orthostatics, just like I know several successful ER docs who never review the old medical records (a task that is also time-consuming and often fruitless). But a superior physician uses all the arrows in his quiver.
Good point about multi-tasking. They key here is symptoms, though. If they have no symptoms when they stand up (which I usually make them do for a neuro exam anyway), then the numbers don't make a difference. OTOH, positional symptoms are in fact highly valuable.
As for docs who don't look at old records, they are just dumb. 5 minutes with the old chart is worth 30 minutes with the patient. It may be dangerous, but it's lazy AND counter-productive to not check the old records.
I appreciate your points, and I even agree with you to some degree. I was just trying to point out that many of the things we do have low sensitivity, specificity, and usefulness.
If you have a middle-aged patient with anginal chest pain, and you dig through the old chart and find that they had a stress test 6 months ago that was normal, is it really going to change your management? Maybe, maybe not.
I do it anyway, because I want to have the data. The more data points I collect, the more likely I am to be able to make the correct disposition.
If you don't think a patient really needs to be admitted, the rest of their exam is unremarkable, and they say they are a little dizzy when they stand up, are you going to admit them for that? If you are going to send them home anyway, it might help to have a set of normal orthostatic VS on the chart. If I'm going to admit them regardless, then I often don't do orthostatics either, but the Medicine admitting doc will probably ask for it.
Just saying.
It is my understanding that the original data on orthostatics were from the 60's and were conducted by phelbotimising some volunteer med students (young people) various amounts of blood. The thing that was most sensitive was the rise in heart rate by 20 points when one went from lying to standing and then waited one minute. It was only useful in those volunteers who had TWO units of blood removed! In those that lost less, it was not reliable. The BP was not very accurate as most people can compromise. It does not apply to the elderly. I usually just hook up my patient to the pulse ox and then stand them up for a minute. I never use the BP.
I love it when you guys fight. ;)
My piddly two cents: Orthostatics can also help diagnose Addison's disease. Well-tanned & fainting when you stand up is not a "good thing".
*popcorn*
Do you really get orthostatics on every dizzy patient? I see plenty of young people with straightforward BPPV. Dix-Hallpike yes, orthostatics no. If that's cutting corners so be it.
I agree that you have to stand most dizzy patients up, but it's their symptoms that direct my management, not the vital signs. I could check cap refill while they're standing too without adding any time, but why bother if it's not going to change anything? Also most of our rooms are non-monitored, so it's not quite as easy to get a BP cuff on them.
I do agree with doing them if your gonna admit and the admitting doc wants them. I order a lot of blood cultures for the same reason.
Do you really get orthostatics on every dizzy patient?
Not necessarily. But incidentally, I never perform the specific Dix-Hallpike test. Everyone has their own style and their own corners they like to cut.
There's more than one way to do this job, obviously.
That is something we can all agree on.
Since orthostatics are so, so important, I think that very highly educated inidividuals are the only ones that can be trusted to do them...and you know who I am talking about - our trusted doctor colleagues...go at it!
As long as you do the enemas, it's all good.
you scoundrel!!
Sorry I missed this thread - I was on vacation...
I'd like to side with Scalpel on this one. It is interesting to read the various commenters dislike for physical exam while not offering an alternative means of evaluation of the patient with syncope - siding with history and chart review as the most valuable evaluation techniques. Hmmm.
While history IS the most helpful, it is also often misleading - particularly in the elderly. Many, many patients do not perceive lightheadedness when orthostatic. Medications today (particularly Hytrin and Flomax) are common causes of easy-to-treat severe orthostatic hypotension that is often not perceived by the patient. But I suppose it's just easier and cheaper to admit the patient.
Or maybe get a CT, EKG, Cardiac enzymes, CBC, chemistry panel, and the like, rather than actuially touching the patient since its sensitivity and specificity is so poor!
Can we name another more cost-effective evaluation than history and physical exam? Unlikely.
And orthostatics as a cause of hip fractures as an excuse for not performing this simple evaluation? Pleaassseee!
We must realize that the main reason people have hip fractures now with orthostatics is because we have abandoned MANUAL BP cuffs for AUTOMATIC ones that can't detect low BP's anyway (yet administrators know better, don't they?). And to think that the diagnosis of pulsus paradoxicus (tamponade) as a cause for syncope without an echo is now a thing of the past. Sad.
So as far as history and physical exam goes, I'd side with Scalpel and say that ALL information is both useful AND inherently exceedingly cost-effective. Too bad we're not paid for the time it takes to do this any longer...
Shadowfax and other nay sayers: The orthostatic test is the simplest way to indicate autonomic dysfunction, undiagnosed - as in those people who keep dropping dead "for no reason," the kids who die after getting overheated or exercising - especially at school - etc. As a parent of a child with autonomic dysfunction, I'm extremely glad that somebody took the time to do this "routine" test - at no extra charge - and referred my child. She carries belladonna now, and when she arrests, we can bring her back. If those other kids [previously displaying NO symptoms] had been evaluated, they might have been diagnosed, and they might be alive today. Death is a greater risk than falling, and reasonable care [prudent?] can prevent a fall.
physicals are great but come to nigeria were we depend only on them and see the problems with diagnosis. . .we sure will do with those your CT and MRI's.
As a nurse on a med/surg unit, I am often ordered( or as I like to say, requested) to do OVS on a lot of my patients whether it makes sense to do them or not! ie. on pt with severe back pain who cannot move! I am on a committee to review our standardized admission orders in regard to the Clinical Value of the orders. There are many times where we do not see the clincal value of these OVS. Certainly dx such as syncope, GI bleed,dehydration all warrant OVS. Can you give me other admitting dx that would warrant OVS as an order? As long as there is true clinical value to doing something, we nurses will be glad to do it! But when the order does not make any sense to do or we see no clinical value....well, we think its just plain stupid and a waste of our time. So if you could, give me a list of dx where OVS would be an appropriate order. Thanks, MB
Only highly educated may perform orthos LOL that's funny I'm a CNA and have watched RN's have pt.'s go from one position to the next with no pause in between, making vs insignificant. After sitting on a panel with Doc's to standerdize certain procedures they verified that proper procedure is 3mins btwn but would be very happy if they could get staff to pause 1.5-2mins. So I did informal survey of the unit asking what most did I had feedback of pause? what pause to ummm 15 mins (yes these are RN's) so this may be why data collected isn't helpful guys. I'm just sayin.....
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