The Benefits of Oral Rehydration on Orthostatic Intolerance in Children with Postural Tachycardia Syndrome (2019) Marvin S Medow, et al

[ahimsa]

The Benefits of Oral Rehydration on Orthostatic Intolerance in Children with Postural Tachycardia Syndrome

Marvin S. Medow, PhD, Kenneth Guber, BSm Shilpan Chokshi, BS, Courtney Terilli, BSN, Paul Visintainer, PhD, Julian M. Stewart, MD, PhD

https://www.jpeds.com/action/showFullTextImages?pii=S0022-3476(19)30893-5

Objective
To evaluate whether equal volumes of oral rehydration solution (ORS) or intravenous (IV) saline provide similar improvements in cardiovascular status during controlled orthostatic challenge when administered to subjects with postural tachycardia syndrome (POTS) with orthostatic intolerance.

Study design
We studied the neurovascular response to fluid loading during orthostatic stress using lower body negative pressure (LBNP) in 10 subjects with POTS with orthostatic intolerance and 15 controls, and on subsequent days before and 1 hour after IV saline infusion or ingestion of ORS.

Results
Subjects with POTS exhibited reduced tolerance to LBNP (P < .0001) compared with controls (Orthostatic Index of 35 715 ± 3469 vs 93 980 ± 7977, respectively). In POTS, following ORS but not saline infusion, cerebral blood flow velocity (CBFv) was significantly higher than that with no treatment, at −45 mm Hg (P < .0005). Although fluid loading did not confer any advantage in controls, subjects with POTS experienced a significant improvement in orthostatic tolerance following both saline infusion (100 ± 9.7 vs 134.5 ± 17.4; P < .05) and ORS (100 ± 9.7 vs 155.6 ± 15.7; P < .001) when evaluated by normalized orthostatic index (P < .001, compared with untreated baseline).

 

[ahimsa]

Study is behind a paywall but I think this blog post is about either this study or a similar one.

https://zebrapit.com/2019/10/30/dysautonomia-study-ors/

But it's confusing since the overview for the study that I posted does not mention ME/CFS at all, and this blog post does, so I could have things completely mixed up. Easy for me to do!

Dr Medow tested a total of 35 people with OI and ME/CFS between the ages of 15 to 29. A portion were given placebo, while others received either a litre of saline intravenously, or an oral dose of ORS. After administration, the patients were placed in a lying position, with the lower half of their bodies covered in an airtight chamber,also known as an LBNP tank. The patients were then subjected to varying negative pressure. The pressure was gradually increased until each patient reached particular levels of OI. The testing was grueling: Most of the patients passed out at some point. My heart goes out to these patients and their bravery, but it seems their hard work has paid off. Not only did they prove both IV and oral rehydration salts to be quite effective in treating OI, but they figured out that one is actually more effective than the other:

“Changes in normalized orthostatic index (% of that measured without treatment in control (black bars) and subjects with POTS with orthostatic intolerance (gray bars) measured following no treatment (Untreated), after infusion of IV saline, and after ingestion of ORS. Neither saline nor ORS increased orthostatic tolerance in untreated controls (P = .46; n = 15), whereas both IV saline and ORS significantly improved orthostatic tolerance (*P < .05 and **P < .001, respectively; n = 10) in subjects with POTS.” Dr. Medow, et al.

I'd love to hear folks thoughts on this. I seem to get a lot of benefit from ORS (eg, Pedialyte type of solutions).

PS. I hope I created this thread correctly!

 

[Lisa108]

Study is behind a paywall

Here is a sci-hub link.

If this one doesn't work in your country, insert the doi number (for this study it is: 10.1016/j.jpeds.2019.07.041) here.

Edited: spelling

 

[Lisa108]

But it's confusing since the overview for the study that I posted does not mention ME/CFS at all,

I think the blogger got something mixed up while interpretating the study.
This sentence

Dr Medow tested a total of 35 people with OI and ME/CFS between the ages of 15 to 29.

is clearly wrong.
Citing from the study, "We enrolled 15 healthy control subjects and 10 with a history of orthostatic intolerance and POTS."

 

[ahimsa]

I think the blogger got something mixed up while interpretating the study.
This sentence is clearly wrong.
Citing from the study, "We enrolled 15 healthy control subjects and 10 with a history of orthostatic intolerance and POTS."

I agree.

My guess is that the blogger is conflating two studies: this study, which was done on patients with OI & POTS, and an NIH study which includes ME/CFS patients.

See https://www.clinicaltrials.gov/ct2/show/record/NCT02854683

Inclusion Criteria:

• Both female and male participants are being studies
• Ages 15-29
• All subjects must fulfill criteria for Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) and include 15 with Neurally Mediated Syncope (NMS) and 15 with Postural Tachycardia Syndrome (POTS).
• ME/CFS patients with NMS will be cases with episodic symptoms of Orthostatic Intolerance (OI) associated with 3 or more episodes of abrupt loss of consciousness and postural tone within the last year (simple faint)
• ME/CFS patients with POTS will have chronic day to day symptoms of OI for at least 3 months. POTS will be confirmed by duplication of these symptoms per tilt table test
• Healthy volunteers will be included and free from any disease

But I don't think there are any results posted from that study yet? Unless the blogger has inside info.

PS. None of the scihub links worked for me. I got what looks like a captcha screen but in Russian?

 

[Badpack]

Ppl need to drink water to live, who would have known without a study.

 

[ahimsa]

Ppl need to drink water to live, who would have known without a study.

It's not water. It's oral rehydration solution (ORS) - water mixed with salts (sodium, potassium).

Also, notice how patients with POTS respond to ORS vs. healthy controls (no response):

"Neither saline nor ORS increased orthostatic tolerance in untreated controls (P = .46; n = 15), whereas both IV saline and ORS significantly improved orthostatic tolerance (*P < .05 and **P < .001, respectively; n = 10) in subjects with POTS.”

 

[Seven]

This is simplistic, those of us who struggle w tummy, the oral solution is contra productive BecuAse gives you diarreah and then you loose more than you take in,”.
For me I do better on IV, feel like normal person. Oral depending on tummy day can make me worse than better. Not the same!!!!

 

[rvallee]

It's not water. It's oral rehydration solution (ORS) - water mixed with salts (sodium, potassium).

Also, notice how patients with POTS respond to ORS vs. healthy controls (no response):

"Neither saline nor ORS increased orthostatic tolerance in untreated controls (P = .46; n = 15), whereas both IV saline and ORS significantly improved orthostatic tolerance (*P < .05 and **P < .001, respectively; n = 10) in subjects with POTS.”

View attachment 9271

So it looks like the simple advice of rehydration formula would be a useful clinical practice but since most physicians reject the very notion, often using scare quotes whenever they talk about "orthostatic intolerance", then that advice is not making its way to patients, out of sheer stubbornness and sunk cost of having denied the thing for so long it would be embarrassing to give that advice without acknowledging how and why such a thing is still being denied.

Although are there side-effects to taking it? Those are always downplayed.

Splendid, though. Medicine truly progresses one funeral at a time, which isn't especially smart and definitely unwise.

 

[Lisa108]

I got what looks like a captcha screen but in Russian?

Yes, it's a captcha.

 

[Jonathan Edwards]

So it looks like the simple advice of rehydration formula would be a useful clinical practice

I didn't see a dummy control though?
There ought to be a double blind arm where there was only dummy fluid replacement, or probably better a dose response curve.

 

[ahimsa]

I didn't see a dummy control though?
There ought to be a double blind arm where there was only dummy fluid replacement, or probably better a dose response curve

Thanks, I was hoping you'd look at this thread!

Would it be possible to create a dummy fluid that would look and taste very similar to ORS? That seems hard. I'm assuming it would be easier to make a dummy IV solution.

But even aside from lack of a double blind arm, I thought it was interesting that according to the graph the ORS, on average, was more effective than IV saline. You'd think patients would expect an IV to work better.

Also, the graph shows LBNP testing (lower body negative pressure). Doesn't that mean the data comparing the healthy controls and patients is from some kind of measurements taken during this LBNP testing? Or is it still from questionnaires about how the patients felt during the LBNP testing?

I thought the "orthostatic index" in the graph was some combination of measurements taken during the testing, not from a questionnaire, but I don't know anything about LBNP.

One link I found:

https://www.ncbi.nlm.nih.gov/pubmed/26205572

Lower body negative pressure (LBNP) is a technique that redistributes blood from the upper body to the dependent regions of the pelvis and legs, thus reducing central venous pressure and venous return. The subject is placed in a cylindrical air-tight metal tank, which is sealed at the level of the iliac crests, and subatmospheric pressure is produced using a vacuum pump. This article reviews the historical background, physiological effects, research findings, and clinical applications of LBNP. LBNP is found in both the basic science and clinical literature, encompassing its diverse investigational and clinical applications. The first references to LBNP were in 1952 describing its effectiveness in inducing hypotensive anesthesia. Major interest in LBNP began in the mid 1960s when it was used to characterize the cardiovascular responses to hemorrhage and orthostatic stress, especially that associated with the weightlessness of space flight; these studies have continued to the present day. Advantages of LBNP for such experimental studies include the following: (1) The degree of central hypovolemia is easily controlled and has a rapid onset and reversal. (2) The technique is repeatable, reproducible, and noninvasive. (3) No exogenous pharmacologic agent is required to produce venous pooling. (4) The findings are independent of gravity. In recent years, a few institutions have applied LBNP clinically to diagnose abnormalities in cardiovascular autonomic function and, when combined with echocardiography, to uncover changes in cardiac performance through analysis of Starling curves.

 

[Jonathan Edwards]

But even aside from lack of a double blind arm, I thought it was interesting that according to the graph the ORS, on average, was more effective than IV saline. You'd think patients would expect an IV to work better.

I actually think is needed is a dose response study. In a dose response study patients have no idea whether or not the dose they get is likely to produce a response. So placebo effects get blunted. Also a true physiological response should have a specific dose-response curve. When you see the DR curves you get a good idea as to what is really going on. Patients are unlikely to be able to relate an oral volume to an IV volume in terms of expectations. A bona fide response should show a plausible equivalence between the two.

With respect to what patients expected I think you have to consider the psychological context to this study. Why are they doing it? The main reason I can think of for comparing oral rehydration fluid with IV is that the investigators would rather like to show that oral rehydration fluid is at least as good. The study may have been sponsored by the company that makes the rehydration mix. So patients may have been tipped the wink that the expectation for the oral fluid is high. Patients are very good at 'helping' researchers to get the results they want, particularly if helping means they go on getting regular attention in the clinic by their favourite researcher.

 

[Jonathan Edwards]

But at least at first pass it looks as if oral is as good as IV, which makes sense and would save a lot of wasted time and money.

 

[rvallee]

I didn't see a dummy control though?
There ought to be a double blind arm where there was only dummy fluid replacement, or probably better a dose response curve.

Yeah, should have used better control but the experience of loss of consciousness is one of those things that anyone who has ever experienced appreciates fully is not something will convince themselves of, definitely the exact opposite. Loss of consciousness is about as pleasant as projectile vomiting.

No difference between both arms in the no treatment seems relevant, but to satisfy skeptics it's necessary to almost exaggerate satisfying controlling for effect. But it's hard to bypass the lack of salty flavor in a plain water control, maybe it was judged to be an invalid control given that so might as well skip. Frankly not a bad judgment, improper control is pretty much as useless as no control.

 

[ahimsa]

Patients are very good at 'helping' researchers to get the results they want, particularly if helping means they go on getting regular attention in the clinic by their favourite researcher.

Good point.

I have a question that I hope makes sense. Is the placebo effect possible when it is an involuntary response?

Just as a silly example, if a patient wants to show good reflexes can they make their knee respond to the reflex hammer more quickly? Conversely, can they suppress the response to make it look like their reflexes are really bad? Or is that out of the patient's control and/or very easy to spot when someone is faking it? I ask because I honestly don't know.

I also don't know to what degree autonomic responses can be influenced by a patient, whether consciously or subconsciously. I mean I know I can change my breathing consciously to be faster/slower, and heart rate is affected by anxiety, etc.

But I'm wondering about more general autonomic measurements? Does the lower body negative pressure testing measure things that are not in the patient's control?

It's related to my earlier question about that graph. What is does the y-axis mean when it says, "normalized orthostatic index"?



Is it some combination of autonomic measurements such as blood pressure, heart rate, etc? And if so, how much can a patient influence this index? A lot? A little? Not at all?

Or is it a measure of symptoms reported by patients during lower body negative pressure testing? Obviously when it is symptoms a patient can either minimize or emphasize them.

I don't know the answer.

 

[rvallee]

Why are they doing it? The main reason I can think of for comparing oral rehydration fluid with IV is that the investigators would rather like to show that oral rehydration fluid is at least as good. The study may have been sponsored by the company that makes the rehydration mix.

Always possible but it seems they went as generic as possible on this:

subjects drank 1 L of ORS (World Health Organization formulation containing Na+ = 90 mEq/L and glucose = 111 mmol/L with a total osmolarity of 311)

Though reading more carefully the untreated is a baseline test both arms went through. Looks good on accounting for placebo as the baselines preceded either of the injection or oral intake with the same methodology.

Which all pretty much confirms what the patient community had already figured out. Next step would figuring out whether this is a viable strategy that can affect quality of life and functioning, or simply something that keeps the worst at bay, as pacing is with us.

 

[TiredSam]

To tell us anything at all they should compare it with giving the children beer and crisps.

 

[SallyC]

A follow up looking at a recommended regime would be a good step. Comparing strategies of frequent, regular intake vs larger more separated doses.

As @rvallee said, patients have to figure this out for themselves but if this became official recommended guidance by gp's in my case I would have felt considerably better months earlier. I found info from other patients and tried drinking a decent amount of water in the early morning before I got up and it made a big difference to how I felt. With hindsight I realised how refreshing my breakfast always was (cereal with milk), because my body was desperate for fluids. A severely ill person shouldn't have to be figuring out their own treatments.

 

[Jonathan Edwards]

But it's hard to bypass the lack of salty flavor in a plain water control,

That is why I think a dose response study is the only way. In pharmacological clinical trials you do not get taken seriously unless you have dose response data. This is pretty much a pharmacological trial. It needs to be done professionally. If ME treatment research is to be raised up to credible levels it needs to use the methods everyone else thinks are minimum requirement.