EMCrit Podcast 20 – The Crashing Atrial Fibrillation Patient

Your patient is pale and diaphoretic. Blood pressure is 70/50. Heart rate is 178. EKG shows atrial fibrillation… What are you going to do???

Yeah, yeah the Pavlovian ACLS response–You cardiovert. Wonderful, except it didn’t change a thing. Now what?

In this episode, I discuss the crashing atrial fibrillation patient.

Shock

If the patient is chronically in atrial fib, the shock rarely works. Your patient is unstable, so you decide to give it a shot. You might as well give yourself the best chance of success, so go right for 360 J on monophasic, or equivalently high on your biphasic. This will not cause more injury than lower joules (Heart 1998, 80:3 and Resuscitation 1998;36:193). PA is probably better than AA if you have pads. Make sure the synch is on.

You need to give your patient something to disguise the fact that you are electrocuting them. Yet you don’t want to drop their pressure. Ketamine is ok in disassociative dosing, but then your patient is loopy and you lose your mental status exam. Consider 5-7 mg of etomidate along with a pain dose of ketamine, 10-15 mg.

Screen for WPW

If you have a. fib with a wide QRS and a rate > 250-300, be scared, very scared. This is WPW and these patients just love to ruin your day by going into v. fib. Shock early, shock often, light them up.

Get the BP Up

So you made sure it’s not WPW and the cardioversion has failed, as it so often does in chronic a. fib. Now you need to raise the BP before anything else. Use push-dose phenylephrine. 50-200 mcg every minute or so until you get the blood pressure above a diastolic of 60; this will temporize the situation and make the patient’s heart more likely to slow down.

Though things look better, you have not really fixed the problem, you have just temporized.

Slow them them down

Give either amiodarone 150 mg bolus and then the drip (may repeat the bolus x 1)

Or

Use diltiazem, but not as a push. Drip it in at 2.5 mg/minute until HR < 100 or you get to 50 mg. (Resuscitation 52:167, 2002) See here for more.

Still not working?

  • Consider magnesium
  • Consider reshocking
  • Consider cardiology consult
  • Consider something else is going on
  • Consider signing out to one of your colleagues and running away
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Podcast 10 – Cardiogenic Shock

heart small Mohamed, a listener from Sudan, emailed asking about the treatment of acute pulmonary edema in patients with low blood pressure. This is in distinction to SCAPE patients (see podcast 1).

If the patients have pulmonary edema and low BP from a cardiac cause, then they are in cardiogenic shock.

First, consider the etiology:

  • Rate-related
  • Valve Disorder
  • Ischemic (Right sided infarct, STEMI, NSTEMI)
  • Cardiomyopathy
  • Toxicologic

At the same time, you are treating the patient with:

  • Inotropes (dobutamine, milrinone, calcium)
  • Pressors to achieve a MAP > 65 (allows coronary perfusion)
  • Oxygenation support, most likely with intubation
  • Optimize O2 carrying capacity (Hb>10)
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EMCrit Podcast 6 – Push-Dose Pressors

Finally a non-intubation topic!

Bolus dose pressors and inotropes have been used by the anesthesiologists for decades, but they have not penetrated into standard emergency medicine practice. I don’t know why. They are the perfect solution to short-lived hypotension, e.g. post-intubation or during sedation.

They also can act as a bridge to drip pressors while they are being mixed or while a central line is being placed.

Click Here for printable sheet with mixing instructions

Epinephrine

Do not give cardiac arrest doses (1 mg) to patients with a pulse

Has alpha and beta-1/2 effects so it is an inopressor

Onset-1 minute

Duration-5-10 minutes

Mixing Instructions:

Take a 10 ml syringe with 9 ml of normal saline

Into this syringe, draw up 1 ml of epinephrine from the cardiac amp (amp contains Epinephrine 100 mcg/ml)

Now you have 10 mls of Epinephrine 10 mcg/ml

Dose:

0.5-2 ml every 1-5 minutes (5-20  mcg)

No extravasation worries!

Mixing Video:

Phenylephrine

Phenyl as a bolus dose is clean, quick, and never causes trouble. But…

It is pure alpha, so no intrinsic inotropy; it may increase coronary perfusion which can improve cardiac output. I only use this in tachycardic patients.

Onset-1 minute

Duration- 5-10 minutes (usually 5)

Mixing Instructions:

Take a syringe and draw up 1 ml of phenylephrine from the vial (vial concentration must be 10 mg/ml)

Inject this into a 100 ml bag of NS

Now you have 100 mls of phenylephrine 100 mcg/ml

Draw up some into a syringe; each ml in the syringe is 100 mcg

Dose:

0.5-2 ml every 1-5 minutes (50-200 mcg)

No extravasation worries!

Mixing Video:

Ephedrine

I don’t use this one, listen to the podcast to hear why. I put it here solely for the anesthesiologists on the blog.

Onset-Near Instant

Duration-1 hour

Mixing Instructions:

Take a 10 ml syringe with 9 ml of normal saline

Into this syringe, draw up 1 ml of ephedrine from the vial (vial contains Ephedrine 50 mg/ml)

Now you have 10 mls of Ephedrine 5 mg/ml

Dose:

1-2 ml every 2-5 minutes (5-10 mg)

No extravasation worries!

Additional Video of a Real Patient

By Larry Mellick’s Crew

Update:

This study compares push-dose phenylephrine to continuous infusion–no difference between the two (Anesthesia Analgesia 21012;115(6):1343)

Now on to the Podcast…

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