Cite this post as:
Scott Weingart, MD FCCM. Podcast 64 – Fluid Responsiveness with Dr. Paul Marik. EMCrit Blog. Published on January 8, 2012. Accessed on May 29th 2023. Available at [https://emcrit.org/emcrit/fluid-responsiveness-with-dr-paul-marik/ ].
Dr. Scott Weingart, Course Director, reports no relevant financial relationships with ineligible companies.
This episode’s speaker(s), (listed above), report no relevant financial relationships with ineligible companies.
Original Release: January 8, 2012
Date of Most Recent Review: Jan 1, 2022
Termination Date: Jan 1, 2025
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I noticed the technology used in the NICOM product runs a small current through the patient at radio frequencies (not sure if it is low-frequency or high-frequency). Does this interfere with the surface ECGs or do the standard monitor-mode filters work fine?
Never noticed a whit of interference thus far
Thanks Scott and Dr Marik
Profound stuff! Keep it up. My service looked into one of these non invasive CO monitors using doppler USS. a few years ago and nothing ever came of it as the evidence at the time was not so convincing. It seems things have matured. prehospital CO measurement…now thats an exciting concept!will chase this up again with my retrieval colleagues!
Going back to transport medicine and going to work in fixe wing and with clinic with low budget and not much technology, what will be my best approach to assess my patient? Been a nurse I may not have access to arterial line unless someone can place them.
Hand-held ultrasound is how I would go for transport.
Hi Scott. Sounds like there has been a lot of movement in this area in just the last 12 months or so. I have been trialling the arterial line based SVV CO monitor and found it has limitations as discussed in the talk with Dr Marik Probably the single biggest limitation is the reliance on the staff to run the machine / calibrate, interpret and “trust” the numbers. There is a lot of fiddle and training required for the device we are using at the moment – and it does rely on a patient being ventilated – so only the… Read more »
Hi Casey, What monitors do you guys run? The Phillips MP line does PPV (aka SVV) out of the box (at least the MP50, 70 and 90’s I play with, not sure about the MP30), so if you have a medium sick patient who you don’t feel like putting a Vigeleo on (I assume it’s a Vigeleo), you can set it up and it spits out a number at you, no fiddling with another machine or otherwise interrupting your workflow; enable it, wait ~30 seconds, and get a number. I use PiCCO and Vigeleo a fair bit, but it can… Read more »
Got a bit worried when he started talking noninvasive! We trialled a bioimpedance device about 7-8 years ago and were way less than impressed. I’ve often wondered why more people don’t use the simplest tests, 500cc bolus or passive leg raise. Dr. Marik shows remarkable common sense.
Scott, thank you for this amazing blog. Besides tons of useful information it’s a great source of inspiration.
Just want to ask what you think of dr Lichtenstein’s protocol where you give fluid till you get the “wet” pattern on lung ultrasound (predominant B-lines)? It’s extremely simple so nice in the ED/non-ICU ward, and you get to see what actually happens in the organ most sensitive to fluid overload. Even SV must be a surrogate parameter in a sense?
in performing the passive leg raise—how long do you wait before rechecking the blood pressure? what are you using as your stroke volume surrogate?–systolic, diastolic, or MAP? I assume we are looking at a greater than 10% increase as being indicative of “fluid responsive”. This seems imprecise without an A-line but you say simple non-invasive BP measurement can work?
Intermittent blood pressure will not work. For an a-line I think a 10% increase in MAP or SBP is a reasonable positive. But if negative, it doesn’t mean the patient is not fluid responsive.
If the result is negative durante the PLR.. should that repeated.. or give the patients medication (inotropics, etc)?
If negative, use pressors or inotropes; recheck for fluid responsiveness in a bit.
Scott – I appreciate the perspective of Dr. Marik, and it was an interesting discussion. It was somewhat frustrating to hear, though, to hear the empiric data for septic shock dismissed out of hand. I would tend to agree about the accuracy of CVP as an isolated measurement of fluid responsiveness, no argument there. However, whatever the limitations of the Rivers trial, it gave us actual outcomes, an NNT for mortality. You can’t ignore the fact that it did so, in part, by using the CVP to guide therapy. Sure, there may have been some clinicians who applied the results… Read more »
Brooks, Thanks for the comment. I can’t say I agree with you. One thing the EGDT trial did not show at all is any value to CVP per se. Both groups got CVP monitoring and both groups had the same CVP goal.
I believe Dr. Marik’s comment re: empiric fluid admin was less a commentary on Rivers’ trial than the ongoing PROCESS trial in which empiric fluid admin without a marker is considered a good idea.
Dr. Weingart, I want to congratulate you for this podcast, it is excelent, for me, the best of the best. I work in Laredo, Tx Doctors Hospital ER and I use a lot of your concepts to take care of my patients. Again congratulations and I hope you
keep on with this cast.
Carlos F Crespo, MD
Much thanks for the feedback, Carlos
Fantastic podcast! I’ve been waiting a while for this one. I have a couple of quick questions though. First, is there any data out there on whether sonographic parameters like IVC collapse or LV diastolic function (like the ultrasound podcast guys suggest) correlate w/ fluid responsiveness vs just static measures like CVP OR PAOP?
Second, and this is just a random thought I had, but what about using a continuous ScVO2 monitor in lieu of the SV monitor in the algorithm above to see if DO2 is increased w/ the fluid challenge?
IVC with mech vent has shown fluid responsiveness; spont resp–nope.
ScvO2 and SvO2 has been used for this purpose (and to decide who needs blood transfusions as well). It is a bit downstream though, and doesn’t measure regional improvements in perfusion.
Does anyone have any experience with the NICOM in the pediatric population? Are there any studies supporting the use of this monitor in pediatrics?
haven’t seen any peds stuff yet
Hi Scott, Loved this podcast. Totally agree with the best measure being actually giving a volume challenge via fluid or passive leg raise and evaluating the results. However, given the infrequency of CO monitoring in my ICU – I do also find myself using a gross assessment of PPV or Systolic pressure variation and IVC distensibility as well as the chart etc in my assessment of whether a patient will be fluid responsive. My question is: Given that we have established that there is poor correlation between CVP and fluid responsiveness, what is the physiological rationale behind why IVC distensibility… Read more »
Assume we are talking about tubed pts on mech vent. In this case, IVC is really resp-dynamic CVP which nobody has looked at and probably would be quite good as opposed to static CVP. What we can say is that we have a bunch of studies on IVC in thsi group and it seems to towk nicely.
How can the CVP be a the devil and the IVC be wonderful. They are looking at the same vessels! I know CVP is pressure and IVC is volume. Is it possible to have a high CVP with a full collapse and possitve IVC exam? Please explain!
Paul, In this case, I assume we are talking spont vent pts. Static CVP may be the devil for fluid responsiveness, but not tolerance. Dynamic CVP may be that much better. IVC in the way I advocate is dynamic and used for tolerance; for this it is pretty good.
Is there a pocket sized US machine that is a reasonable cost? It would be great to see an adapter for a phone of tablet device to allow one to reasonably assess fluid responsiveness ASAP especially in HEMS. Or even better perform a FAST in the field to discover what you don’t know yet but will discover as VS decrease.
I was not yet impressed with the ones I have found. Write the ultrasoundpodcast.com guys on their site as they have access to the cutting edge devices.
Study done at a hospital I worked out employing non-invasive monitoring: Dunham CM, Chirichella TJ, Gruber BS, et al. Emergency department noninvasive (NICOM) cardiac outputs are associated with trauma activation, patient injury severity and host conditions and mortality. J Trauma Acute Care Surg. 2012; 73(2): 479-485 BACKGROUND: Anoninvasive cardiac output (CO) monitor (NICOM), using Bioreactance technology, has been validated in several nontrauma patient studies. We hypothesized that NICOM CO would have more significant associations with clinical conditions than would systolic blood pressure (sBP). METHODS: This is a prospective observational study of consecutive trauma activation patients during the first 10 to… Read more »
Review article by Dr Marik is now published:
fantastic–thanks for the heads up
hey scott, you mention the NICOM is inexpensive. Can you give me a rough ball park figure re cost? I know that it will vary between countries/hospitals etc but just a ball park would be great.
Hi Scott. Just referenced this podcast with Sepsis Alliance for Trinity Health Care. Thanks so much
Hey Scott, Our shop has been using the NICOM’s now for about 1 year. I have had mixed feelings about them. I am actually going to be giving an informal lecture to residents and looked at a lot of the data. Although it all looks great on paper, in my experience I have issue with the CO/CI readings. I feel can be quite inaccurate. I have actually had cardiologists come and calculate CO and it was way off. This is usually in those with severe HF (which correlates to some of the literature) but I feel its these patients where… Read more »
only utility of these monitors, if there is a utility is in the trend. changes of SVi with fluids, interventions etc. I too trust none of the absolutes in any altered pathophysiology
scott what would bp rise be by nibp for use as tool in prehospital related to sv ?
Please note that Dr. Marik has received money for lectures from Cheetah.
I think this should be noted in the COI and in the interpretation of his reviews and thinking.
HI I too was wondering about this. Typically an objective source would not recommend a modality. Do you have any examples of $ for lectures, he says he has no conflict of interests.