Cardiac vs Pulmonary Dyspnea - New tool to assess COPD/CHF

[Buddy]

We've all had the same call numerous times. A patient with mixed COPD and CHF/Cardiac history complaining of shortness of breath. Their lungs sound like garbage and the family may or may not know if any distal edema present is new, or increased from baseline. There is a tool available now that is being used in many emergency rooms, including the Cleveland Clinic, to assist clinicians in differentiating cardiac versus pulmonary causes of dyspnea. It is called Impedance Cardiography. The service I work for is in the process of developing a pilot project to see how paramedics respond to the technology and whether or not it would be practical to use in the field. Should the pilot work out, they may purchase some impedance cardiography devices for use in the field.

Impedance Cardiography involves a device called the BioZ Monitor (Z is the symbol used to denote impedance) that utilizes impedance signals to track aortic blood flow. It is simlar to an EKG, but instead of electrical function/ryhthm, it gives readouts on the mechanical function of the heart such as cardiac output, stroke volume, vascular resistance and thoracic fluid levels, along with a number of other hemodynamic parameters (even some dealing with contractility). Studies have demonstrated that ICG has resulted in a significant change in ER physician diagnosis as to the cause of dyspnea, and a resulting significant change in course of therapy.

It would seem there is a place for this technology in EMS. The value in determining cardiac vs pulmonary causes of dyspnea would certainly help avoid a patient in acute heart failure being treated with beta agonist bronchodilators that can increase heart rate and myocardial oxygen demand.

I just wanted to put this out there to see what response there might be from other EMS professionals. If the pilot project is successful, and there is a demand, the company who produces the equipment might be persuaded to produce a device specific to the needs of EMS workers in the field.

Here is a link to some articles on Impedance Cardiography used in dyspnea:

http://www.cdic.com/cdclin30.html#Dyspnea

Two that are of high relevance found at this link are:

Impedance Cardiography Changes Therapy in Dyspneic Patients: Results from the ED-IMPACT Trial. (Peacock et al.)

and

Utility of Impedance Cardiography to Determine Cardiac vs. Noncardiac Cause of Dyspnea in the Emergency Department. (Springfield et al.)

There are other clinical studies listed on the link above, just scroll up and down. There are plenty on Critical Care, ER, Dyspnea and Heart Failure.

An article that describes all the hemodynamic parameters and what they mean can be found at:

http://www.impedancecardiography.com/icgprog10.html

It is the one called:

"A Clinical Guide to Interpreting ICG Hemodynamic Status Report"

If you have an interest in participating in or any questions about the pilot project, please feel free to contact me. My e-mail is mbseak@verizon.net. I can also be reached via pager at 716-459-9566. I truly believe that this technology can help save lives in the hands of paramedics.

[Ridryder 911]

Sorry, I cn not get the links to open. Is this the same as external prediction of C.O. and SV as well predicatble EJF index ?... I have seen these in use and thought they are a great tool, and we have one in the CCU where I occcasionaly work. But, the costs of $25K is too prohibitive at this time for it. (If this is the same device)

Thanks for the info...

Ridryder 911

[Buddy]

Hello- If you copy and paste the links into your browser, you should be able to view them. They are PDF files, so you may need to get the free Adobe Acrobat reader at www.adobe.com. It is likely the same device. Yes, it is a non-invasive hemodynamic monitor. The trade name is BioZ. Yes, the cost is high, but in our pilot project, we are going to place one unit on a supervisor vehicle, and they will respond to all shortness of breath indicators for patients over a certain age, or where there is known cardiac and/or COPD history.

One of the parameters, Systolic Time Ratio does have a general correlation to ejection fraction, but there is no direct conversion chart for STR to EF. Basically, if the STR is high, or has increased significantly in a patient, the likelihood is they have experienced a decrease in left cardiac function.

If the results of the pilot project are favorable, the company who makes the monitor may be persuaded to develop an EMS specific product-- either a module to plug into a monitor/defib, a stand alone monitor/defib with ICG capability or maybe a small hand held device that would report only on the two parameters necessary to help differentiate cardiac vs pulmonary dyspnea.

[Ace844]

Sorry, I cn not get the links to open. Is this the same as external prediction of C.O. and SV as well predicatble EJF index ?... I have seen these in use and thought they are a great tool, and we have one in the CCU where I occcasionaly work. But, the costs of $25K is too prohibitive at this time for it. (If this is the same device)

Thanks for the info...

Ridryder 911

I had the same issue as "rid," even the copy paste thing didn't work....

out here,

Ace844

[Just Plain Ruff]

This post content might change as soon as I can read the pdf files that were linked to the post but until then from the information presented here is my take:

forgive me for ignorance but who is going to truly benefit from these devices. From a purely financial statement how will the services recoup the cost of one of these devices? I mean, if one costs even a fraction of the quoted price of 25K such as something in the area of 5K and these are used only a fraction of the time then how much will the patient be charged.

Also how much is insurance going to cover?

I know it is probably too early to talk cost but that has to be a significant factor in determining the need for these devices.

Are they going to tell a medic in the field anything new or more important. I for one know that I care very little what the patients ejection fraction is. You can rest assured that if the patient fits into the criteria for putting one of these on them then they probably have a crappy EF anyway so will this information be of any real calculable use for medics in the field when a large percentage of transport times are 30 mins or less.

This is a good idea but I don't really see the efficacy of putting something like this machine on every ambulance. Maybe helicopters or rigs that have a routinely long and I mean greater than 1 hour transport time.

[Buddy]

Ruffems- Sorry about the problem with the links, when I roll the mouse over them on the website, the URL address that showed up on the bottom bar of my browser is what I put in. To access the articles I referred to, go to:

http://www.cdic.com/cdclin30.html#Dyspnea

The two I cited were:

Impedance Cardiography Changes Therapy in Dyspneic Patients: Results from the ED-IMPACT Trial. (Peacock et al.)

and

Utility of Impedance Cardiography to Determine Cardiac vs. Noncardiac Cause of Dyspnea in the Emergency Department. (Springfield et al.)

There are other clinical studies listed on the link above, just scroll up and down. There are plenty on Critical Care, ER, Dyspnea and Heart Failure.

The article that describes al the hemodynamic parameters and what they mean can be found at:

http://www.impedancecardiography.com/icgprog10.html

It is the one called:

"A Clinical Guide to Interpreting ICG Hemodynamic Status Report"

As far as giving medics new, useful information-- Absolutely! In the Springfield article, they concluded that 2 parameters were key indicators as to whether or not dyspnea was cardiac or pulmonary in nature. If the cardiac index (the patient's cardiac output indexed to their body surface area-- CO/BSA in meters squared) was less than 2.4, or if the Systolic Time Ratio was greater than .55 with a cardiac index of less than 3.0, it was highly indicitive of a cardiac cause for the dyspnea. Systolic Time Ratio is a ratio between the Pre Ejection Period and the Left Ventricular Ejection Time. PEP is the time from the electrical stimulation of the ventricles to the opening of the aortic valve. LVET is the time from the opening of the aortic valve to the closing of the aortic valve. As a heart begins to fail, the PEP time lengthens, because it takes more time for the heart to generate enough pressure to open the aortic valve. LVET decreases, because the heart cannot maintain enough pressure to keep the aortic valve open for a long period of time. The result is a higher number (PEP) divided by a smaller number (LVET) in a failing heart and a resulting higher STR.

This is valuable information for paramedics to know in the field, and it is not available through other means. If a paramedic chooses the wrong protocol to treat a dyspneic patient, say treating a CHF patient with albuterol as they would a COPD'er, the results can be disasterous. We all know albuterol is not terribly selective, having beta 1 and beta 2 effects. The beta 1 effects can increase myocardial oxygen demand and worsen an acute CHF event. Anything that can help medics in the field differentiate cardiac from pulmonary causes of dyspnea is a good thing. Also, changes in stroke volume/index are seen before you see a change in cardiac output/index and any clinical signs of failure. If you see stroke volume tanking, it may not be long before CO tanks and also the patient.

This will not tell ejection fraction, but the device will help determine with a higher level of certainty if dyspnea is cardiac in nature.

I believe in the future, ICG will be an invaluable tool in EMS. A lot of people were reticent about pulse oximetry, and now it is considered the 5th vital sign. I wish I could find the exact quote, but when the blood pressure cuff first came out, a well noted physician at the time commented on how awkward and time consuming the sphygmomanometer was and how in a busy physician office there was hardly time for such nonsense. Can you imagine not having blood pressure today?

As for cost, billing and practicality, that is why we are doing the pilot project. In the ER, they bill it under APC code 0099, and I think the amount is around $26. Physicians in the ER can bill an interpretation fee, which I think is about $10. In a physician office, the amount averages $45-55 per test, CPT code 93701. Rather than a stand alone unit, it may make more sense to incorporate ICG monitoring into an existing monitor/defib design.

If you are interested, perhaps your service can participate as part of the pilot. Call me at 716-459-9566, or e-mail mbseak@verizon.net.

[Ace844]

"Buddy",

Out of curiosity, do you work in the Field" at all? Do you work for this company? What level of funding/support did this corporation provide for these studies..? I have a few more ?'s, but I'll hold them until after you answer...Thanks in advance,

Ace844

[Ridryder 911]

Personally, I hope they do become popular.. I bought stock in this company 5 yrs ago...haven't seen a return yet...

Be safe,

Ridryder 911

[Buddy]

ACE844- Yes, I do work in the field as a Paramedic one to two 12 hour shifts per week and I am also a preceptor and field training officer for new paramedics and paramedic students for an ambulance service in the Buffalo, NY area. I am also a certified ACLS and PALS instructor.

I did take a position with CardioDynamics last month. One of the main reasons I sought them out was because I truly believe in this technology and that it is has amazing potential for the future of EMS. I actually had a very secure full time job in pharmaceutical sales prior to joining CardioDynamics, but I gave it up because I believe in this comapny and the benefits that this technology has to offer patients. I have not undertaken this EMS pilot project for financial gain-- my bread and butter right now with this device is in physician offices. If anything, it is additional work I have taken on with little hope of much return in the very near future, if ever. My idea with the pilot project is to first see how paramedics and EMS medical directors respond to the technology and if it is practical out in the field. We will also be exploring issues of billing and reimbursement for ambulance services for this procedure. We will be gathering data points similar to those found in the ED-IMPACT study. I have edited the links I provided in the original post so that people can find the relevant articles/studies on this technology, but here they are again:

http://www.cdic.com/cdclin30.html#Dyspnea

Two that are of high relevance found at this link are:

Impedance Cardiography Changes Therapy in Dyspneic Patients: Results from the ED-IMPACT Trial. (Peacock et al.)

and

Utility of Impedance Cardiography to Determine Cardiac vs. Noncardiac Cause of Dyspnea in the Emergency Department. (Springfield et al.)

Some studies were funded by the coporation, some were funded by other interests. The Mayo Clinic ran a study on hypertension on their own to try and "debunk" the technology and wound up determining that our device allowed for 70% better control of hypertension than specialist care alone!

An article that describes all the hemodynamic parameters measured by the device and what they mean can be found at:

http://www.impedancecardiography.com/icgprog10.html

It is the one called:

"A Clinical Guide to Interpreting ICG Hemodynamic Status Report"

I personally think it would be fantastic if a version of this product could be developed for EMS that made it practical (i.e. size wise, or something where ICG was integrated into an existing monitor/defib platform). It would be great even if all it could do was help medics differentiate cardiac vs pulmonary dyspnea, but it can do so much more. The prospect of having live time readings on cardiac output, stroke volume, vascular resistance and thoracic fluid levels just boggles my mind. I know I would have use for it personally, the question is does EMS in general? That is where this pilot project comes in. Maybe it will be determined that it is not practical, or that EMS just isn't ready for this technology yet, but at least I will have tried, and I can live with that.

Just so you understand the passion I have for EMS, I'll tell you the reason I became a paramedic. I was an 18 year old freshman in college. On April 19, 1990, at approximately 7:00pm, a class mate of mine collapsed in our Tae Kwon Do class. I was CPR trained from having been a lifeguard, so I initiated CPR and another trained classmate joined me and we performed CPR until the student and then vilage rescue squads arrived. Our classmate did not make it. All I can remember is the doctor at the hospital coming out to the waiting room to tell all of us. All I could do is stare at the floor through a flood of tears while everyone gathered around to tell me I did all I could. The village ambulance service where I went to college did not have defib capability at the time, who knows if it would have helped, it turned out he had a congenital heart defect. From that day on, I had a burning passion for EMS, especially in the area of defib access. I took that passion and my instructor group ran a pilot project to upgrade Certified First Responders to defib capability. We ran over 900 Buffalo Firefighters through our program in under 2 years.

I now have the same passion for this technology. I have seen what it can do in hospitals and doctors offices, and I truly believe it is lifesaving technology. I have had physicians who have it tell me they would not dream of practicing without it now that it is available.

Now I hope you can see where I am coming from.

Feel free to contact me at 716-459-9566 or e-mail mbseak@verizon.net

[AZCEP]

I am all for using new technology to help with patient care, but I share the concern for cost and utility. This sounds very exciting, but carries the same issues of all the other exciting technology that has hit the prehospital arena of late.

I work in an area that has been historically hesitant to invest in new technology that has not shown a definite benefit in changing the ways that a patient will be cared for. As examples, some of the local agencies have balked at buying TCP capable cardiac monitors, 12-lead capable cardiac monitors, waveform capnography, even pulse oximeters met resistance.

So while I am sure that this new monitoring tool will prove it's utility to a specific group of patients, how will it improve on a thorough history and physical exam?