What do you use to guage CPR adequacy?

[Jwade]

In the age of practicing Evidence Based Medicine, I am curious how everyone guages if CPR is being performed effectively? I would also like you to document your answers with evidence and NOT anecdotal stories.

For example, Do you check Femoral Pulse? Do you use EtCo2? Do you use an Art Line? Do you just make sure proper rate and depth are being performed?

I will start the discussion with saying my practice is to use Proper Rate and Depth along with Waveform EtCo2. Femoral Pulse Checks are useless and should not be done. I have the studies to back this up, and will post them when we get some responses.

Thanks in advance.

JW

[ERDoc]

Why don't you post the studies so that we can have a discussion and people can add their opinions as we go.

[scubanurse]

Everywhere I have run a code has used EKG waveform during CPR and the presence of a femoral pulse...

I know I'm new and blond, but how does ETCO2 tell you CPR is being performed adequately? I thought that was used to determine if ventilation were adequate? And yes, ventilation is one part of CPR... is there another use for it?

I am curious to see these studies about the femoral pulse checks in CPR... I would think that if a femoral pulse is present, adequate perfusion to the brain was occurring?

[HERBIE1]

Prehospital, the sign that CPR is being properly performed is indeed a palpable pulse- if you feel a femoral pulse, then clearly you are doing effective CPR. Oxygenation-o2 sats, ETCO2, color improvement, EKG changes to a viable or shockable rhythm vs an agonal rhythm, pupils constricting(before Atropine administration), etc- all indicate how things are going. As for checking the femoral pulse, in a prehospital setting, some things are also easier said than done, based on the scene, the patient's size, are you in a moving rig, the level of training and experience of the person monitoring that pulse, etc. I've had first responders and EMTB's tell me they feel a return of a pulse when a person is clearly in a confirmed asystole.

If the patient "looks" better, then clearly you are doing things correctly. All the gadgets in the world are great but I think you also need to correlate them with the clinical picture.

If we cannot get a ROSC, then our job is to keep the patient as viable as possible until the ER can pick up care and possibly provide an intervention or medication that we cannot.

Obviously with CPR, ensuring proper compression rate and depth is useless unless the patient is being adequately oxygenated, so I guess the more ways you have to measure a patient's condition, the better idea you have of how effective your efforts are and what, if any adjustments need to be made.

[Jwade]

Herbie,

First, Please don't regurgitate a bunch of anecdotal stories you have been taught your whole life. If one knew anything about anatomy and physiology one would understand that trying to feel a femoral pulse during the presence of CPR ( when cardiac output is at most 20% or normal) is nothing more than RETROGRADE BLOODFLOW! Again, one has to have a good understanding of what NORMAL anatomy is all about.

For your reading pleasure.

(Circulation. 2005;112:IV-78 – IV-83.)

© 2005 American Heart Association, Inc.

2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

8. Connick M, Berg RA. Femoral venous pulsations during open-chest cardiac massage. Ann Emerg Med. 1994; 24: 1176–1179.

Assessment During CPR

At present there are no reliable clinical criteria that clinicians can use to assess the efficacy of CPR. Although end-tidal CO2 serves as an indicator of cardiac output produced by chest compressions and may indicate return of spontaneous circulation (ROSC),1,2 there is little other technology available to provide real-time feedback on the effectiveness of CPR.

Assessment of Hemodynamics

Coronary Perfusion Pressure

Coronary perfusion pressure (CPP = aortic relaxation [diastolic] pressure minus right atrial relaxation phase blood pressure) during CPR correlates with both myocardial blood flow and ROSC (LOE 3).3,4 A CPP of 15 mm Hg is predictive of ROSC. Increased CPP correlates with improved 24-hour survival rates in animal studies (LOE 6)5 and is associated with improved myocardial blood flow and ROSC in animal studies of epinephrine, vasopressin, and angiotensin II (LOE 6).5–7

When intra-arterial monitoring is in place during the resuscitative effort (eg, in an intensive care setting), the clinician should try to maximize arterial diastolic pressures to achieve an optimal CPP. Assuming a right atrial diastolic pressure of 10 mm Hg means that the aortic diastolic pressure should ideally be at least 30 mm Hg to maintain a CPP of 20 mm Hg during CPR. Unfortunately such monitoring is rarely available outside the intensive care environment.

Pulses

Clinicians frequently try to palpate arterial pulses during chest compressions to assess the effectiveness of compressions. No studies have shown the validity or clinical utility of checking pulses during ongoing CPR. Because there are no valves in the inferior vena cava, retrograde blood flow into the venous system produce femoral vein pulsations.8 Thus palpation of a pulse in the femoral triangle may indicate venous rather than arterial blood flow. Carotid pulsations during CPR do not indicate the efficacy of coronary blood flow or myocardial or cerebral perfusion during CPR.

Assessment of Respiratory Gases

Arterial Blood Gases

Arterial blood gas monitoring during cardiac arrest is not a reliable indicator of the severity of tissue hypoxemia, hypercarbia (and therefore the adequacy of ventilation during CPR), or tissue acidosis. This conclusion is supported by 1 case series (LOE 5)9 and 10 case reports10–19 that showed that arterial blood gas values are an inaccurate indicator of the magnitude of tissue acidosis during cardiac arrest and CPR both in and out of hospital.

Oximetry

During cardiac arrest, pulse oximetry will not function because pulsatile blood flow is inadequate in peripheral tissue beds. But pulse oximetry is commonly used in emergency departments and critical care units for monitoring patients who are not in arrest because it provides a simple, continuous method of tracking oxyhemoglobin saturation. Normal pulse oximetry saturation, however, does not ensure adequate systemic oxygen delivery because it does not calculate the total oxygen content (O2 bound to hemoglobin + dissolved O2) and adequacy of blood flow (cardiac output).

Tissue oxygen tension is not commonly evaluated during CPR, but it may provide a mechanism to assess tissue perfusion because transconjunctival oxygen tension falls rapidly with cardiac arrest and returns to baseline when spontaneous circulation is restored.20,21

End-Tidal CO2 Monitoring

End-tidal CO2 monitoring is a safe and effective noninvasive indicator of cardiac output during CPR and may be an early indicator of ROSC in intubated patients. During cardiac arrest CO2 continues to be generated throughout the body. The major determinant of CO2 excretion is its rate of delivery from the peripheral production sites to the lungs. In the low-flow state during CPR, ventilation is relatively high compared with blood flow, so that the end-tidal CO2 concentration is low. If ventilation is reasonably constant, then changes in end-tidal CO2 concentration reflect changes in cardiac output.

Eight case series have shown that patients who were successfully resuscitated from cardiac arrest had significantly higher end-tidal CO2 levels than patients who could not be resuscitated (LOE 5).2,22–28 Capnometry can also be used as an early indicator of ROSC (LOE 529,30; LOE 631).

In case series totaling 744 intubated adults in cardiac arrest receiving CPR who had a maximum end-tidal CO2 of <10 mm Hg, the prognosis was poor even if CPR was optimized (LOE 5).1,2,24,25,32,33 But this prognostic indicator was unreliable immediately after starting CPR in 4 studies (LOE 5)1,2,32,33 that showed no difference in rates of ROSC and survival in those with an initial end-tidal CO2 of <10 mm Hg compared with higher end-tidal CO2. Five patients achieved ROSC (one survived to discharge) despite an initial end-tidal CO2 of <10 mm Hg.

In summary, end-tidal CO2 monitoring during cardiac arrest can be useful as a noninvasive indicator of cardiac output generated during CPR (Class IIa). Further research is needed to define the capability of end-tidal CO2 monitoring to guide more aggressive interventions or a decision to abandon resuscitative efforts.

In the patient with ROSC, continuous or intermittent monitoring of end-tidal CO2 provides assurance that the endotracheal tube is maintained in the trachea. End-tidal CO2 can guide ventilation, especially when correlated with the PaCO2 from an arterial blood gas measurement.

Cheers.

John Wade MBA, FP-C

Everywhere I have run a code has used EKG waveform during CPR and the presence of a femoral pulse...

I know I'm new and blond, but how does ETCO2 tell you CPR is being performed adequately? I thought that was used to determine if ventilation were adequate? And yes, ventilation is one part of CPR... is there another use for it?

I am curious to see these studies about the femoral pulse checks in CPR... I would think that if a femoral pulse is present, adequate perfusion to the brain was occurring?

Kate,

There is nothing wrong with being new and certainly not blonde. :-)

It only means you have limited experience, and probably no critical care experience. Again, nothing wrong..

Your BLOOD PRESSURE is going to be the only reliable means of brain perfusion. Remember NORMAL CPP ( cerebral perfusion pressure is 70 for an adult.

We can calculate CPP by taking your MAP - ICP = CPP Mean arterial pressure - Intercranial pressure = Cerebral Perfusion Pressure

SO, For example, if you have someone with a ROSC, and a BP of 60 / 40. What is your CPP?

Calculate MAP is Systolic + 2* Diastolic / 3

60+80 = 140 / 3 = MAP 46.6

Obviously we cannot calculate ICP without a bolt sticking out of the head, but a reliable estimate in a NON-Head Injured patient is 10% of your MAP. So a Map of 46 gives you 4.6

MAP - 46.6

ICP - 4.6

= CPP = 42 SO, we know that NORMAL adequate perfusion of CPP is 70, with the above BP you are at 42. It goes without saying, you are not doing a whole lot for his brain perfusion with a CPP of 42.......

As far as ETC02 is concerned, THERE is a TON that WaveForm ETCo2 can tell someone. Again, this is far above your average 911 paramedic level training, but once you learn it and how to apply it in critical care settings, you will always want it......:-)

Let me know if you have any questions.

Respectfully,

John Wade MBA, FP-C

[mobey]

In the age of practicing Evidence Based Medicine, I am curious how everyone guages if CPR is being performed effectively? I would also like you to document your answers with evidence and NOT anecdotal stories.

For example, Do you check Femoral Pulse? Do you use EtCo2? Do you use an Art Line? Do you just make sure proper rate and depth are being performed?

I will start the discussion with saying my practice is to use Proper Rate and Depth along with Waveform EtCo2. Femoral Pulse Checks are useless and should not be done. I have the studies to back this up, and will post them when we get some responses.

Thanks in advance.

JW

Please read your question

At present there are no reliable clinical criteria that clinicians can use to assess the efficacy of CPR

Now this quote is one of the first lines in RED you posted.

Seems like you posted this to stroke your own ego.

You specifically asked how WE assess proper CPR, then after the very 1st post, you slam the guy stating there is NO proper assessment backed up by evidence.

Duhhh......

[scubanurse]

Please read your question

Now this quote is one of the first lines in RED you posted.

Seems like you posted this to stroke your own ego.

You specifically asked how WE assess proper CPR, then after the very 1st post, you slam the guy stating there is NO proper assessment backed up by evidence.

Duhhh......

I second that Mobey...

Anywaysss moving on from that delightful review session and the assumption we don't know anything about anatomy and physiology...

[HERBIE1]

I second that Mobey...

Anywaysss moving on from that delightful review session and the assumption we don't know anything about anatomy and physiology...

Pretty interesting- and arrogant- assumption, isn't it? Based on the responses here, it would seem that many folks have training far beyond the "average 911 paramedic" provider.

Problem is, unless I'm wrong, the original poster seemed to be asking what we can do PREHOSPITAL to assess the efficacy of CPR.

Quantitatively we are limited in our measurements and methods, but there are also qualitative methods to gauge how the patient is responding.

Things like ABG's, arterial pressures, and ICP's are nice, but I seem to have misplaced the triple lumen kits in the rig...

[ERDoc]

Herbie, I think you need a bigger rig. I will admit that I have not reviewed the original article or the sources cited in it. Lack of evidence is not the same thing as evidence against. If you don't have an ideal test you have to accept the next best thing. I agree with Mobey, maybe the OP had good intent by bringing up this thread but the way it was carried out was very condescending.

[EMT Martin]

We have one of those neat, confangled auto-pulses. I've watched the EKG's when the medic shows up, and it's got a very consistant compression set down. Every spike shows up neatly as the last. But we tend to use a combination of EKG, femoral pulses, 12 leads, SpO2, and the old saying "if you're not breaking ribs, you're not doing it right."

...should be noted I haven't been on very many codes, though. Three.