ABG's on during a code?

[DrStevo]

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Is there a reason that doing ABG's during a code is stupid?

 

[ChildNeuro]

Is there a reason that doing ABG's during a code is stupid?

Heres from http://www.americanheart.org/presenter.jhtml?identifier=3026300, I found this on a google search and read it in about 30 seconds total:

While a blood gas upon initiation on CPR and resuscitation efforts may give a direction as to the source of the arrest, the most vital aspect appears to be the ph value, which can be obtained from venous blood. In an acidotic environment, resuscitation medications do not work. The effectiveness of resuscitation efforts is directly related to the ability of medications to be effective. Most medications do not work in environments less than 7.00, and work most effectively in ph values greater than 7.20 ish. When we removed the use of sodium bicarbonate from algorithms, we deemphasized the need for a normal blood ph value. In emergency situations, the ability to normalize ph values by oxygenation alone takes too much time.

I have only incedental evidence in many actual resuscitation efforts. We generally sent a stat lab which include a blood gas and potassium, ionized calcium, glucose and hemoglobin levels, preferably an arterial sample. This test, called a critical care panel, includes many of the most correctable sources of arrests and comes back in sufficient time to make a difference in resuscitation efforts.

I would love to see studies performed to verify or refute my observations.

COI: I am a critical care nurse at a university hospital, University of Illinois, and teach ACLS and BLS through the hospital and through the ACES company based in Illinois. I have seventeen years of ICU/ER experience and respond to resuscitation efforts throughout the hospital on a rotating basis as well as ICU efforts. I also teach crash cart review courses within the hospital. I am currently enrolled at University of Illinois college of nursing in a master's program in critical care nursing but have no current research in progress, nor am I involved in the research of others. My emphasis of study is in staff development.

 

[jdh71]

Is there a reason that doing ABG's during a code is stupid?

Stupid? It's not a such a horrible idea in the abstract, but highly impractical. Truth is most codes don't end well for the patient, and if you are really worried about a pH less than 7 just give them the biacarb and hope for the best. Patients that code because they are so acidotic are likely "gonners" anyway - what are you going to do get them hooked up to dialysis during the code? The ABG will merely confirm what should already be a clinical suspicion and is really little help.

 

[DrStevo]

To explain..during a code I was the first doctor to arrive at the scene and while thinking of possible causes I asked for a ABG..and one of the nurses just snickered at me, which made me think I did something stupid..and my mind was all racing because it was my first code by myself. Thanks for the replies

 

[jdh71]

To explain..during a code I was the first doctor to arrive at the scene and while thinking of possible causes I asked for a ABG..and one of the nurses just snickered at me, which made me think I did something stupid..and my mind was all racing because it was my first code by myself. Thanks for the replies

First guy there . . . first code - perfectly understable, and nurses can be such a-holes to new residents, huh? I say just run the "by the book" ACLS if you're the only guy there until the cavalry shows up and you can confer and bounce ideas. Hell, if in doubt, give 'em some sugar, give em some bicarb, give em some naloxone 😀 Bu always follow the protocol and no one will really fault you

When in doubt . . . epi 👍

 

[ChildNeuro]

To explain..during a code I was the first doctor to arrive at the scene and while thinking of possible causes I asked for a ABG..and one of the nurses just snickered at me, which made me think I did something stupid..and my mind was all racing because it was my first code by myself. Thanks for the replies

Usually people are very serious during a code, that is weird that a nurse would snicker, remember that nurse's, while trained to do their job well don't have the same training as doctors. We are forced to analyze a clinical situation by habit and decide upon lab tests and treatments and as doctors can come up with a tailored treatment for a patient you won't find in any textbook. We must think throught the pathophysiology from the molecules up, some nurses are excellent at this, but other focus on solely symptomatology and standard treatment. I.e. a nurse practicioner can treat asthma exacerbation, etc. . . but may lack the indepth knowledge of pulmonary disease, due no fault of their own, just they don't learn that in med school, and would miss alot of rare pulmonary diseases that a pulmonologist knows by heart. In my limited experience, when a nurse in an ED or elsewhere was looking over my shoulder and said that patient doesn't need this or that examined or whatever lab test, usually I would go ahead and do it, because my training told me it was important, but the nurse didn't know why and thought to myself, "No, I really need to do this test or examine this because that is what a med student/doctor/resident would do." Nurses always criticize when you break protocol or what they believe to be standard treatment for a given disease, but the evaluation step between disease and treatment is what we focus on, and unfortunately, nurses may not get alot of this training and sort of have to connect A to C without knowing about B. They snickered at you because all they see is someone breaking protocol and in their eyes wasting time, when in actuallity it was a good learning experience for you, may be useful, and there is a pathophysiologic reason for doing it, i.e. it would be good to know ABG before bicarb admin as alkalosis is generally more dangerous than acidosis.

 

[jdh71]

i.e. it would be good to know ABG before bicarb admin as alkalosis is generally more dangerous than acidosis.

Not really. Your couple amps of bicarb are not going to throw a seriously acidotic patient <7.0 into alkalosis. If you suspect acidosis - give 'em the bicarb, hell with it. I mean, your looking at a PEA or flatline, that chance you are getting them back is somewhere close to the proverbial snowball in hades - it does occasionally happen.

Besides if Stewart's physical chemical derivation for acidosis (do a google) in the human physiological system is correct, and I think it is, bicarb has NOTHING whatsoever to do with physiologic pH. *gasp* But, but, but, we learned in pathophys . . . Read the theory. Acidosis is a product of strong anions in the system - lactate being the biggie in a nonbreathing patient. Best thing you can do in this situation is get an airway and keep the CPR going baby! Oh, yeah, and if you have a mind for it . . . pray . . . it's like the bicarb: why not? 😀

 

[ChildNeuro]

Not really. Your couple amps of bicarb are not going to throw a seriously acidotic patient <7.0 into alkalosis. If you suspect acidosis - give 'em the bicarb, hell with it. I mean, your looking at a PEA or flatline, that chance you are getting them back is somewhere close to the proverbial snowball in hades - it does occasionally happen.

Besides if Stewart's physical chemical derivation for acidosis (do a google) in the human physiological system is correct, and I think it is, bicarb has NOTHING whatsoever to do with physiologic pH. *gasp* But, but, but, we learned in pathophys . . . Read the theory. Acidosis is a product of strong anions in the system - lactate being the biggie in a nonbreathing patient. Best thing you can do in this situation is get an airway and keep the CPR going baby! Oh, yeah, and if you have a mind for it . . . pray . . . it's like the bicarb: why not? 😀

Bicarb may or may not have anything to do with maintenance of physiologic pH, but that is not to say that IV Bicarbonate, which is the cornerstone of treatment of severe acidosis does not increase the pH, obviously it does. You can add bicarbo to any aqueous solution and it will increase the pH by neutralizing acid. Obviously, some amount of bicarb given IV will be toxic and lethal to a patient, i.e. you can kill a patient with bicarb by raising the pH to dangerous levels. If your carbonic anhydrase in type 2 RTA is defective, you have trouble making/retaining bicarb, and you get acidotic. I think it is clear that bicarb is involved in acid/base disorders in that way even if the pathophysiology isn't known, but then again bicarb IV is a medication which does neutralize acid and raise pH . . .

 

[jdh71]

Bicarb may or may not have anything to do with maintenance of physiologic pH, but that is not to say that IV Bicarbonate, which is the cornerstone of treatment of severe acidosis does not increase the pH, obviously it does. You can add bicarbo to any aqueous solution and it will increase the pH by neutralizing acid. Obviously, some amount of bicarb given IV will be toxic and lethal to a patient, i.e. you can kill a patient with bicarb by raising the pH to dangerous levels. If your carbonic anhydrase in type 2 RTA is defective, you have trouble making/retaining bicarb, and you get acidotic. I think it is clear that bicarb is involved in acid/base disorders in that way even if the pathophysiology isn't known, but then again bicarb IV is a medication which does neutralize acid and raise pH . . .

I'm assuming you are pretty green out of basic sciences (just an observation, not an insult) and I would also say you're pretty sharp . . .

You are making a number intuitive jumps, which I'm not really interested in making a pissing contest over, but on what are those connections founded? Add bicarb to a beaker of HCl and we see an increase in pH. Ok. The beaker's a neat closed, simple system. Is the body the body the same?

Did you even explore the theory? Let me repeat . . . following the mathematical derivation as outlined by Stewart (Stewart PA. Modern quantitative acid-base chemistry. Can J Physiol Pharmacol. 1983;61:1441–1461) there is NO physical way the bicarb affects the pH in the body outside of very limited, very local effects - it's the physics that don't allow for it to happen. How is bicarb given? NaHCO3, right? It is the presence of the extra strong cations that actually raise the pH. Same phenomenon with the carbonic anhydrase inhibitors . . . stop the reactions and you will not get the H+/Na+ exchange at the tubule, and therefore no K+/Na+ exchange at the plasma level. Less reabsorbtion of cations the more H+ present in the plasma as a matter of necessity of balancing charge with the anions present and a lower pH.

It's fascinating!

Bicarb has no influence on acid base disorders but it is a useful marker for following them.

If you're really interested, look for anything by Kellum. He's a critical care attending and the phyisical chem acid/base guru out of UPenn or Pittsburg . . . i forget which