The Futility of Orthostatic Measurements

Are you still doing othostatic measurements (i.e. lying and standing blood pressures or heart rate changes) for assessing volume status and acute volume loss?

Maybe you’ll stop after hearing Anand (@EMSwami) Swaminathan’s investigation into the (lack of) evidence for this widely accepted pseudoaxiomatic urban legend:

Assess for orthostatic symptoms, not BP changes.

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  1. Lauren Stiles, Esq. says

    As a patient who was misdiagnosed for nine months because no doctor bothered to do orthostatic vitals on me, I would have to respectfully disagree with EMSwami’s recommendation to stop doing orthostatic vitals in the ER. It may not be the best way to determine volume status, but it has other clinical utility.

    I presented to my local ER here in NY numerous times over a nine month period after unexplained fainting episodes and sometimes just severe lightheadedness. Each time, my vitals would be taken in the supine position in the hospital bed, and my vitals were “perfect” so I was dismissed as just being anxious or attention seeking. I followed up with my primary, who also took my vitals supine and told me everything was fine.

    Nine months after my near daily fainting episodes began, a neurologist at Cornell finally bothered to check my vitals in the upright position. My BP dropped like a hot potato and my pulse jumped from 75 to 175 just from standing still for a minute. He diagnosed me Postural Tachycardia Syndrome (POTS) caused by autonomic neuropathy, and a year later Cleveland Clinic determined that my POTS/autonomic neuropathy was caused by Sjogren’s Syndrome. We are aggressively treating my Sjogren’s and my autonomic dysfunction has greatly improved.

    I was lucky to get diagnosed within the first nine months. The average young woman with POTS takes years to get diagnosed, in large part because when they present at the ER immediately after a syncopal episode, or with acute lightheadedness, no one is bothering to check their vitals in the upright position.

    All patients presenting in an ER for lightheadedness and syncope should have their orthostatic vitals documented, and should be referred to a cardio or EP for appropriate follow up.

    Sincerely,

    Lauren Stiles
    President & Co-Founder, Dysautonomia International
    http://www.dysautonomiainternational.org

    PS -- Persistent hypovolemia is common in the majority of POTS patients. One theory is that it is due to a partial sympathetic dennervation of the kidney. Read more in Circulation: http://circ.ahajournals.org/content/111/13/1574.full

  2. says

    I’m happy to hear that you were diagnosed and that you are doing well.

    I think there is some confusion as to what we are discussing here. My talk specifically addresses the utility of orthostatic measurements to diagnose patients with moderate blood or volume loss. Autonomic dysfunction does not have to do with volume loss. The major point here is that roughly 50% of people will be orthostatic by measurements when they are asymptomatic and have no volume loss and that many patients with moderate volume loss will not be orthostatic by measurements in spite of being symptomatic. The key is that we should not rely on numbers but rather on patient symptoms.

    If a patient presents with recurrent syncope, a full workup (inpatient or outpatient) should be performed and neurologic causes would be important to consider. However, neurologic cause of syncope is not an Emergency Department diagnosis. It should be made be a primary doctor (or a neurologist) after extensive workup to exclude immediately life-threatening conditions including dysrhythmias. Additionally, these conditions are quite rare and should not drive Emergency Department workups.

    The summary here is that over-reliance on orthostatic measurements to determine volume status is useless. The patient’s symptoms are what should be attended to.

    • Lauren Stiles, Esq. says

      Dear Dr. Swaminathan,

      In understand your point that orthostatic vitals are not a useful measure of volume status and that symptoms are more important than numbers.

      I also understand that the ER is not the place to go for a diagnosis, but I still think it should be standard practice to record orthostatic vitals on patients presenting with complaints of syncope or pre-syncope.

      Very often syncope and autonomic dysfunction patients do end up in ER when they have a syncopal or near-syncopal episode. In my own experience, and in the experience of many others our non-profit has surveyed, these patients are usually sent home being told nothing is wrong if no one bothered to do orthostatic vitals on them. Unless you are referring all syncope or pre-syncope patients for a subsequent full work up when they show up in the ER (and kudos to you if you are!), it is likely that they will not get referred for that work up for a very long time; delaying their diagnosis resulting in wasted medical resources, increased costs, and needless suffering. Most of your ER peers are not referring syncope or pre-syncope patients for a work up. They are taking BP in the supine position and telling them nothing it wrong. In younger syncope patients and female syncope patients whose vitals are normal in the supine position, they are more likely to referred for a psych consult than a cardio/EP work up.

      It’s easy to say, well their primary care doctor should handle this. I agree, but for the most part, they are not taking orthostatic vitals either. And sometimes a patient’s orthostatic vitals will be normal when they are not symptomatic. They end up in the ER when they are symptomatic. Waiting for a week for a primary care appointment means that you may not be symptomatic when you finally get to see your primary. This is why I am urging you to have someone do orthostatic vitals on your syncope or pre-syncope patients.

      I would like to clarify that primary and secondary autonomic disorders, as a whole, are not rare. The most common primary autonomic disorder is POTS. Mayo Clinic’s Chief of Pediatric & Adolescent Medicine, Dr. Philip Fisher, estimates that 1 out of 100 teens develops POTS before adulthood. This is about 500,000 teens in the US (and these teens are heavy users of ER departments before they are accurately diagnosed). If you add the adult onset POTS patients, the estimates of the US POTS population range between 500,000 and 1,000,000 individuals. There are many peer reviewed publications noting this.

      Add to this individuals with disabling forms of neurocardiogenic syncope (not your typical one time fainter, but someone who is fainting often enough to impact their quality-of-life), individuals with with neurogenic orthostatic hypotension secondary to Multiple System Atrophy and Parkinson’s, the 20-25% of diabetics with diabetic autonomic neuropathy, and individuals with non-diabetic autonomic neuropathy secondary to lupus, Sjogren’s, RA and other assorted causes of autonomic neuropathy. Clinically significant autonomic disorders are not rare at all. I think the belief that autonomic disorders are rare persists because, for the most part, most doctors are not looking for them.

      You state “[a]utonomic dysfunction does not have to do with volume loss.” A person who has lost blood due to an injury does not necessarily have an autonomic disorder. However, some autonomic disorders DO result in hypovolemia. Please read the article I cited in my PS above. These patients will end up in your ER, and if you only do standard blood tests looking for dehydration, you won’t see their hypovolemia, because it’s usually a deficit in plasma and RBCs. Bedside orthostatic vitals can confirm a POTS diagnosis, and can let you know that it’s OK to give saline even when their bloodwork doesn’t evidence dehydration.

      You cite one of Dr. Julian Stewart’s articles in your lecture to prove your point. I would encourage you to be in touch with him about this. He’s a very nice guy who runs the Center for Hypotension at New York Medical College. He has some differing views on this than you do and he can probably explain what I’m trying to say much more eloquently than I can.

      Kind regards,
      Lauren

  3. says

    Lauren -- thank you again for your interest in the topic. Further discussion is both important and always welcome.

    In terms of patients with recurrent syncope, multiple medical issues etc, these patients are rarely discharged after a syncopal episode without either an inpatient workup or plans for an outpatient workup (agreed upon with a primary). I don’t think these patients are relevant to the discussion.

    Performing orthostatics on all patients with syncope would likely lead to far more false positives than true positives. What would be the recommendation? Should all patients that have positive orthostatics be admitted for workups? The strain on the hospital system would be phenomenal and unnecessary. If the recommendation is that these patients should be followed up in an outpatient setting, I would argue that orthostatics don’t change this since all patients should be followed up in the clinic or outpatient setting.

    Should all young patients with a single syncopal episode have a complete syncope workup? I don’t think so. Again, the strain on our health care system would be enormous. Recurrent syncope in a young person? Completely agree that an appropriate work up should be performed. Asking the Emergency Department to do this (along with establishing advanced directives in all older patients, performing HIV testing, Blood pressure screening and other non-Emergent issues) is not the way to go. It’s not simply that we want to do less. We want to turn out attention to the interventions that make a difference now. I would rather spend 5 minutes talking to the patient with chest pain to make sure we aren’t missing a subtle presentation of aortic dissection or pulmonary embolism. I’d rather spend an extra 5 minutes making sure that abscess is completely washed out of pus. I’d rather spend an extra 5 minutes determining the barrier to care for the patient with DKA for the 5th time this month. There are areas that are limited time and resources should be directed.

  4. Abdul says

    This is another argument suggesting the futility of commonly used practices to not only help in diagnosis but also save valuable taxpayers money.

    As a counter argument one could say that the sensitivities reported in your references actually encourage one to use this inexpensive treatment modality. How much does it cost to do an orthostatic vital sign versus the cost involved to do an invasive cardiac monitoring to determine the fluid status?

    I am an internist and was once called to evaluate a patient with an episode of syncope. An ER doc and a neurologist had already ordered imaging studies including CTA of head and neck, MRI of brain and a plain CT of head. After asking a couple of questions patient revealed a history of recent diarrhea and not enough hydration at home. His orthostatic was positive. I took liberty in cancelling all the studies. Gave him a couple liter fluids and discharged him from the ER.

    Obviously this is not a generalization and there are many aspects of our management. I also have great respect for what our ED physicians do for the patients in timely diagnosing and triaging. I completely disagree with labeling an inexpensive test which can some times add valuable information to the diagnosis as futile.

    How sensitive is interpretation of EKG by a non cardiologist physician? How sensitive is auscultation in picking up consolidation? How sensitive is auscultation of heart in picking up mumurs? I’m sure the sensitivity is quite low but we don’t abandon those things just because how inexpensive they are and if picked up then how much specific they can become.

    Regards,

    Abdul

  5. says

    Abdul -- thanks for your feedback. Advanced imaging clearly is not indicated for simple syncope and this has extensively been discussed in the past. The difficulty with orthostatics is not only the sensitivity but the specificity. 50% of those with orthostasis by numbers are not volume depleted. They key is not with the numbers but with the symptoms. If they feel lightheaded when the stand or sit from lying down, they are volume depleted. I just advocate not relying on numbers. The patient’s symptoms always trump the numbers

  6. steve stein says

    The problem that Ms. Stiles is missing is that there are many people with orthostatic changes in BP. The more important test would be just to note in the history that you pass out every time you stand up. Every time you do a test it can result in dangerous, expensive, and wasteful scary work ups. Do we do a complete renal workup for every instance of hypertension -- even if it just transient? Look at what we are learning about mammograms and the fear and expense that screening is potentially causing. PSA screening, cholesterol, the list goes on. It is too simple to just do tests -- even clinical tests -- that are not very specific and start workups. In the Stiles case there was daily syncope -- presumably with standing -- I would guess after “nine months of nearly daily fainting episodes” and literally 100s of syncopal episodes (as is inferred by the story) that orthostatic vital signs would commonly have been done -- and indicated.

  7. says

    From a purely pathophysiological point of view it seems arbitrary to determine a fixed value for HR and BP change in relationship to a allegedly quantifiable volume loss.

    a) In most studies quoted, true volume deficit would have been fairly hard to define
    b) Each patient will vary significantly in their ability to compensate to this circulatory challenge. The elderly patient who is beta blocked, on nitrate patches with autonomic neuropathy is not going to tolerate fluid depletion less than a young patient
    c) Orthostatics only measures changes in systemic arterial pressure. It doesn’t factor in that cerebral autoregulation will also influence whether the patient feels pre-syncopal (again probably a function of age, disease and medications)

    The important thing is that orthostatics does tell you is not the blood volume depletion but whether the presumed insult (small or large) has reached the ability of the patient’s ability to compensate. This is probably the greater value of the evaluation.

  8. says

    Nor should we see the value of postural drop as a dichotomous outcome. As with any physiological value that gauges circulatory function e.g. BP or LVOT VTi, the magnitude, trend and response to therapy is important (taken always in conjunction with other information).

    We must be wary of a creating a straw man argument. In any single variable analysis, whether it is fever in appendicitis or hypoxia in PE, is that invariably you are going to demonstrate poor specificity or sensitivity. The totality of data is what is important.

  9. says

    We dont do it to assess volume status! There are so many other factors at play. Eg the old guy on an alpha blocker and multiple antihypertensives who couldnt hold his BP and gets dizzy and is prone to falls. Having documented in the notes that his blood pressure holds up when he stands, and having a physio or care coordinator to walk him around confidently (with no symptoms) is reassuring for discharge planning.

    • says

      I don’t fully agree here. First off, most of the time, orthostatics are being done to check for volume status and this is the indication that these measures were initially created for.
      The point of my video is that the symptoms of orthostatic hypotension trump the numbers you get. All you need to do is stand them up. If they feel lightheaded, they’re orthostatic. All the numbers do is confuse things.

      • says

        Methinks how someone decides to use postural BP changes is up to them. Your presentation just says that a 20mmHg change (an arbitrary cut-off) is not associated with moderate volume depletion (which you don’t actually define).

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