Noninvasive Cardiac Monitoring

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

Noyac

Full Member
15+ Year Member
Joined
Jun 20, 2005
Messages
8,022
Reaction score
2,815
Looking at some noninvasive monitors. What's the consensus on them? Which are the better products? Where does the Edwards Clear Sight EV 1000 stand?

Members don't see this ad.
 
Looking at some noninvasive monitors. What's the consensus on them? Which are the better products? Where does the Edwards Clear Sight EV 1000 stand?

We use the edwards clear sight at my program. We have some staff that absolutely dont believe it while others think its equivalent to invasive.

When ive used the clear sight, its been very handy, but i also feel it can be a bit fincky at times. The device you attach is also very bulky.
 
monitor.png
 
Members don't see this ad :)
I've used the Clear Sight. It's ok. It seems pretty accurate most of the time, but occasionally the readings don't make sense or agree with the cuff pressures. I find the setup cumbersome and bulky. The machine I've used can hookup to both the noninvasive and invasive (a-line) monitor. It's good for those borderline cases where you want a little more information, but an a-line seems like overkill.
 
  • Like
Reactions: 1 user
So the rep hooked this system up to me today.
According to this fancy device, I am the healthiest person alive.
While I am pretty damn healthy, I sort of doubt the numbers it put up.
Makes me wonder how accurate it really is.
 
  • Like
Reactions: 1 user
So the rep hooked this system up to me today.
According to this fancy device, I am the healthiest person alive ...

congrats - go celebrate with a scotch and a cigar
 
  • Like
Reactions: 1 user
This isht is all smoke and mirrors. It's all bloody bollocks. ICU nurses absolutely love it. Pretty pictures are great and all. But take care of the patient, not the monitor!

The Edwards Flotrac technology is not even close to accure WRT cardiac output if your patient is on pressors. Most of the people in whom I give a isht about measuring cardiac output are on pressors.

I have had two personal incidents where I had tamponading patients and the Edwards monitor said the CI was 2.5. The nurses assumed everything was fine and patient almost died. There are case reports of people getting CPR and the Flotrac says all is well.

It's fine if not on pressors and volume is indicated, but you don't need a bazillion dollar monitor to tell you that.

Yeah it gives you SVV, but you can see stroke volume variation on your monitor without it.

I used to use this stuff. One day a light went on and I realized it was all unnecessary.

/Rant
 
  • Like
Reactions: 12 users
Use both the clear sight and flo track on same patient and then try to figure out what number is accurate...you quickly stop paying attention bc they are often very different especially in pts where you are titrating Meds for hemodynamics.
 
  • Like
Reactions: 1 user
I agree with HB. The CT surgeons here ask that we use the Flotrac on hearts, in addition to PAC and TEE (because they want to still see CI after they d/c the Swan on POD1), and I used to be a proponent of the device, as I had a good number of patients in whom the three sets of values correlated decently enough. However, I since had a long stretch where the Flotrac would be way off (SV 60-70mL by PA or TEE, but 100mL by Flotrac), despite a totally normal arterial waveform waveform, no pressors, 8mL/kg ideal TV, etc. With the inability to guess when it would and would not be accurate without something better to compare, I abandoned it.
 
  • Like
Reactions: 1 user
But the nursing rep told me "it's been benchmarked and it is NASA technology". I tried this thing once and realized it wasn't what was billed and when the rep is a nurse who is trying to teach me about physiology (and clearly didn't understand it herself), I say BS.

Additionally, each finger probe is $300. I have seen many of these monitors fall by the wayside because they just are not accurate enough or don't work well enough. If you need an a-line, put in an a-line.
 
  • Like
Reactions: 1 user
I've seen people in my program use the ClearSight in patients that are borderline art line candidates for hemodynamics without the need for blood draws especially if they look like difficult art line sticks. If you look at the finger cuff on the thing, it is only really designed to work on patients with normal sized hands. Anyone with sausage finger type hands (those you might actually use it on) the readings are questionable at best. Maybe there is an appropriate niche for it, but I don't know what it is. There will likely always be devices trying to be as accurate as invasive monitors, but they simply aren't as good. Stick with the gold standard.
 
  • Like
Reactions: 1 user
This isht is all smoke and mirrors. It's all bloody bollocks. ICU nurses absolutely love it. Pretty pictures are great and all. But take care of the patient, not the monitor!

The Edwards Flotrac technology is not even close to accure WRT cardiac output if your patient is on pressors. Most of the people in whom I give a isht about measuring cardiac output are on pressors.

I have had two personal incidents where I had tamponading patients and the Edwards monitor said the CI was 2.5. The nurses assumed everything was fine and patient almost died. There are case reports of people getting CPR and the Flotrac says all is well.

It's fine if not on pressors and volume is indicated, but you don't need a bazillion dollar monitor to tell you that.

Yeah it gives you SVV, but you can see stroke volume variation on your monitor without it.

I used to use this stuff. One day a light went on and I realized it was all unnecessary.

/Rant

Hey man, we agree the flo-trac is helpful if the patient is NOT on any pressors or inotropic agents. We have covered this before over the years. Assuming there isn't significant AI the use of these devices can be helpful for many cases; I understand that you sit your own cases vs my practice where I have a midlevel provider doing the case. You dismiss the technology without seeing its full value in the ACT model.

http://www.omicsonline.org/failure-...ardiac-surgical-patient-2155-6148.1000234.pdf


I prefer the "invasive" version where an arterial line is placed over the non invasive one as the numbers seem more valid IMHO.

http://ccforum.biomedcentral.com/articles/10.1186/cc11846
 
Last edited:
Members don't see this ad :)
The author's also found a ‘bias’ and concluded that the Nexfin device is not interchangeable with invasive monitoring and may be used to detect variations in blood pressure. The two articles in the journal truly show us that the Nexfin device is not perfected as yet and anaesthesia providers should refrain from using the non-invasive device. In patients with stable haemodynamic parameters, an upper arm BP cuff is still the way to go. For decades, non-invasive blood pressure cuffs have been used in most patients and invasive arterial catheters in high-risk patients. These are the ‘gold standards’ in anaesthesiology practice.

http://bja.oxfordjournals.org/content/115/1/130.1.full
 
Consequently, the clinical reliability of continuous NIBP systems such as Nexfin or CNAP is arguably determined by the ability of the clinician to appreciate the quality of the pressure waveform. We would therefore advise any clinician who has access to a continuous NIBP monitoring system to use it several times in patients along with invasive and NIBP monitoring in order to learn to appreciate the quality of the signal and the additional information obtained by the non-invasive technology. We expect they will observe the same results as we demonstrated in our report, namely, sometimes a considerable bias with the IBP, to a degree unacceptable in many patients, but with a bias that is considerably smaller than conventional intermittent NIBP.

http://bja.oxfordjournals.org/content/115/1/130.2.full
 
For decades, non-invasive blood pressure cuffs have been used in most patients and invasive arterial catheters in high-risk patients. These are the ‘gold standards’ in anaesthesiology practice.

Yeah, I think in the right setting (including postop!) the FloTrac software that attaches to the a-line can be very helpful and readily reproducible. It's not an absolute requirement for a good anesthetic, but with trained personnel who know how to properly use it...

We have ClearSight here, and for now it feels almost like a gimmick - it appears to work well but often shorts out/has problems or doesn't correlate with the cuff. Maybe it's not quite ready for prime time? Plus you can't draw blood from it...
 
Edwards/Flotrac purchased the Nexfin technology for their latest and greatest flotrac device.

Low risk= Cuff

High Risk= Arterial Line

Moderate risk= ?? is this the right indication for the Nexfin? Nexfin plus traditional cuff BP readings for moderate risk patients
 
Blade, the problem I have with your argument [that it helps you oversee and manage the care of midlevels] is this: these devices can tell you that things are going well when in fact they are not.

If they underestimated cardiac output, and as such forced users to prove to themselves that things were in fact fine, I'd be OK

But again, I have witnessed myself, on more than one occasion, cases in which nurses saw normal values on the noninvasive monitor and then discounted other data that should have alerted them that things were in fact going very badly.
 
  • Like
Reactions: 1 users
Blade, the problem I have with your argument [that it helps you oversee and manage the care of midlevels] is this: these devices can tell you that things are going well when in fact they are not.

If they underestimated cardiac output, and as such forced users to prove to themselves that things were in fact fine, I'd be OK

But again, I have witnessed myself, on more than one occasion, cases in which nurses saw normal values on the noninvasive monitor and then discounted other data that should have alerted them that things were in fact going very badly.

I find these devices helpful at the start of a case to estimate SVV and SV. I take the C.I. With a grain of salt. Once any inotropes or vasoporessors are started the flotrac becomes a very inaccurate device. Like anything else it has its limitations but I use the device several times per week with good results.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3547212/
Flotrac is best used to estimate SVV:
https://www.ncbi.nlm.nih.gov/pubmed/19151280

https://www.ncbi.nlm.nih.gov/pubmed/21892779
 
Last edited:
I find these devices helpful at the start of a case to estimate SVV and SV. I take the C.I. With a grain of salt. Once any inotropes or vasoporessors are started the flotrac becomes a very inaccurate device. Like anything else it has its limitations but I use the device several times per week with good results.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3547212/
Flotrac is best used to estimate SVV:
https://www.ncbi.nlm.nih.gov/pubmed/19151280

https://www.ncbi.nlm.nih.gov/pubmed/21892779

The pulse ox may be good enough for detecting variability when it is significant.
 
So what you are all saying is that I might not be the healthiest person alive?
 
I agree with HB. The CT surgeons here ask that we use the Flotrac on hearts, in addition to PAC and TEE (because they want to still see CI after they d/c the Swan on POD1), and I used to be a proponent of the device, as I had a good number of patients in whom the three sets of values correlated decently enough. However, I since had a long stretch where the Flotrac would be way off (SV 60-70mL by PA or TEE, but 100mL by Flotrac), despite a totally normal arterial waveform waveform, no pressors, 8mL/kg ideal TV, etc. With the inability to guess when it would and would not be accurate without something better to compare, I abandoned it.

Many moons ago the rep brought it into our hospital to trial. Used it once and that was it. Didn't see a reason to have all this numbers on hand whether they were accurate or not. I'm one of those who does a whole case with a TEE and/or a swan and never checks a cardiac output.
 
  • Like
Reactions: 1 users
But the nursing rep told me "it's been benchmarked and it is NASA technology". .

When people say stupid things like that I ask if those NASA they are referring to are the same ones who sent the Challenger (and Columbia I might add) shuttle into space. Then, I give them a look of disapproval.
 
Revisiting...our hospital system is shoving these down our throat for ERAS patients.

Anyone have updates or further insight for the EV 1000?
 
Many moons ago the rep brought it into our hospital to trial. Used it once and that was it. Didn't see a reason to have all this numbers on hand whether they were accurate or not. I'm one of those who does a whole case with a TEE and/or a swan and never checks a cardiac output.

Nice. I thought I was the only one who never presses “start cco”. These machines and the numbers they report are bull****. I love invasive pressures and waveforms but I couldn’t care less about calculated flow. Firstly, the number is incredibly inaccurate regardless of the equipment, second, there are so many factors to consider when deciding if an output is too low or too high that I would rather just blind nurses to the number because they don’t know what to do with it.

Although I do literally always calculate cardiac output with the TEE when I have one.
 
  • Like
Reactions: 1 user
Every one of these that I have ever tested work great in young, healthy, normotensive patients. In the patients who are old, sick, low cardiac output, transplant blah blah blah sick, these are worthless. So they work great when you don't care about what they have to say, and work like ish when you have a patient where the info is helpful.

It's been a few years since I stopped looking at them though. Perhaps they have improved. I doubt it.
 
  • Like
Reactions: 2 users
Revisiting...our hospital system is shoving these down our throat for ERAS patients.

For what it's worth, my hospital's ERAS program is pretty robust (every nonambulatory surgery!) and none of the protocols involve CO monitors, PPV, PVI, esophageal doppler, blah blah blah.

The upshot of goal-directed fluid therapy, really, is avoiding excess fluid, i.e., only giving fluid when there is frank hypovolemia. This is pretty easily done when a) most patients drink a carb drink right before coming in, and b) you actually try as a group to minimize fluid (e.g., minimize fluid "creep," subtly shame the high-fluid-givers).
 
  • Like
Reactions: 1 user
We use Nexfin device to measure blood pressure continuously but there is also ECG module attached. The problem is there is no software installed on the device so we are not able to provide ECG signal.

There is an information in the users guide that ECG software is necessary. Unfortunately our kit does not contain CD nor USB drive with it.

Does someone have ECG software to Nexfin 2.0?
 
Edwards/Flotrac purchased the Nexfin technology for their latest and greatest flotrac device.

Low risk= Cuff

High Risk= Arterial Line

Moderate risk= ?? is this the right indication for the Nexfin? Nexfin plus traditional cuff BP readings for moderate risk patients
this is one of my issues with this technology -- is a arterial line placed by a proficient operator with ultrasound high risk? not even close.

further, the majority of patients who look like good candidates for this stuff are vasculopaths getting shortish procedures done. Unfortunately the fact that they are a vasculopath inherently lowers my confidence in the technology as applied.

I can’t believe I’m saying this but “show me the algorithm”.
 
  • Like
Reactions: 1 user
this is one of my issues with this technology -- is a arterial line placed by a proficient operator with ultrasound high risk? not even close.

further, the majority of patients who look like good candidates for this stuff are vasculopaths getting shortish procedures done. Unfortunately the fact that they are a vasculopath inherently lowers my confidence in the technology as applied.

I can’t believe I’m saying this but “show me the algorithm”.


I think @BLADEMDA means we should use an Aline for high risk patients and procedures, not that an Aline itself is high risk. I agree with this.
 
  • Like
Reactions: 2 users
Trash. Straight in the bin.
 
  • Like
Reactions: 1 user
Top