Wednesday, August 13, 2014


Resuscitation drug adrenaline research in cardiac arrest study

A story on the BBC website brings up a lot of good discussion points.

1. Is epinephrine the right thing to give during a cardiac arrest?

This comes up quite a bit in discussions I have with other MDs. It is unknown. There is some evidence that sooner is better, some that less is better than more. We went away from the high doses we gave in the 90's, so it is realistic that we could move away from it altogether. I am not sure what will be the deciding point.Likely it will be a rogue system that decides to do without it and then shows their survival rates.

2. How can you figure these things out with patients who can not consent to participate in research?

To really know what works in cardiac arrest you need many patients. then you need them to consent to be part of the study.

So I ask the reader Knowing what you know, if you arrested, would you want epinephrine or not?

In the environment of patient safety, you need permission from a patient or family to put them in a study. The scene of a cardiac arrest is not optimal for any consent process.
So it falls to the IRB and community to decide if they are going to support doing the research without traditional consent. IRBs are going to approach it very differently and you may have extensive requirements to do it, like have community forums for people to ask questions.

3. Who would pay for it?

All of this comes at a cost, and then think about how many patients you would need to enroll. There is precious little funding for something like all of this. epinephrine is not a new drug that has a strong upside of success driving investors.

I think it is going to come down to someone deciding to go against the AHA guidelines, and current community (herd) practice and stop using it. If they doing everything else in the arrest the same, any change in survival would be a crude representation of the effects of epinephrine.
It would be a leap for any service.


Monday, May 19, 2014

Calcium, Oh Calcium. Why do you come in 2 forms?

( If you are in a hurry, skip to the red sentences.)

We had a recent caller from the north metro request a clarification about calcium, specifically for the magnesium toxicity prooblem you may see when transporting a patient with pre-term labor.

The background is that magnesium relaxes smooth muscle. This is great when the smooth muscles of the uterus are contracting, or, in theory, the smooth muscles of your lungs are tightening during an asthma attack.

It follows that too much magnesium can make other smooth muscles stop working. This would include your diaphragm ( a smooth or involuntary muscle) and the muscles that run your reflexes ( also smooth or involuntary muscles.) So too much magnesium makes your breathing slow down and you reflexes go away, that is how you measure toxicity.

If you decide your patient on a magnesium drip is getting toxic, you should first turn off the magnesium drip. Then you should give calcium as an anti-dote.

And that is where we run into trouble. The ALS trucks carry calcium chloride for the purposes of cardiac arrests and elevated potassium. This is a fine medication for use in magnesium toxicity. Just put the whole ampule (1 gram) in over 10 minutes.

If you happen to get a calcium gluconate from the hospital, use it the same way, the whole ampule in 10 minutes.

Yes, the two have different amounts of elemental calcium in them. If you ask a chemist, they will sat that 1 ampule of calcium chloride has 272 mgs of calcium in it, while 1 ampule of calcium gluconate has 90 mgs of elemental calcium in it.

For medical use, we are only concerned about the clinical effects and 1 ampule of either will have the same effect

The only reason I can figure why gluconate is preferred over chloride when a magnesium drip is the problem is this:

Calcium Chloride will combine with magnesium and form a solid when used in the same IV line.

If you use the Calcium chloride, you have to use another line.

It is not an issue with calcium gluconate.

Wednesday, January 8, 2014

New Study shows the importance of following guidelines in cardiac arrest management

Anyone who works in pre-hospital care has to know that THE hot topic for the past 3-5 years has been cardiac arrest. New science is coming out every month. This is helping us rapidly refine the best practice for managing a cardiac arrest outside of the hospital.

Ahhh, outside of the hospital. What about in-hospital cardiac arrest? A NEJM article published in 2012 puts the survival rate at 22%. That is much better than out-of-hospital rates which are often quoted as below 10%. It seems logical that the survival rate would be better in a hospital, what better place to have and arrest than in the hospital.But, even if you are in a hospital, there may be some room for improvement.

Consider an article published right now in Resuscitation.Title:

The effect of adherence to ACLS protocols on survival of event in the setting of in-hospital cardiac arrest.

The article says that when a person arrests in the hospital, they have a greater chance of ROSC if ACLS guidelines are followed. They make the point that omitting interventions, or adding in your own that are not part of the protocol, leads to ROSC less often.

This is the key. Managing a cardiac arrest is not a free for all. It needs to be done via a plan that everyone knows, agrees to and understands. It is not a time to be unprepared, random and unpredictable.