Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Cardiac Arrest

The trial was just published today in the NEJM and authored by the Resuscitation Outcomes Consortium Investigators (including our own chair Dr. Ornato).

In short there was no difference in survival or neurologically intact outcome between amiodarone, lidocaine, and placebo for refractory ventricular fibrillation or pulseless ventricular tachycardia.

However, this may not argue against antiarrhythmics in cardiac arrest as there was no increase in adverse events in the experimental groups either and there was an increase in ROSC in the antiarrhythmic groups.

Ondansetron and QTc Prolongation

You may recognize an author on this study just published in Academic Emergency Medicine on New Year’s Eve.

They recorded serial EKGs on 22 ED patients who received 4 mg of ondansetron. There was a small measurable prolongation of the QTc interval (20 ms, 95% CI = 14 to 26 ms) with a maximum QTc of 415 ms. The authors concluded that while the sample size was small, the clinical impact would likely be minimal.

New AHA 2015 CPR/ECC Guidelines

The AHA just released the new 2015 guidelines. Click here for a summary or visit the full website.

A quick list of some changes I noticed:

Methodology

  • Changed recommendation system to GRADE

BLS

  • CPR compression rate should be at least 100 and not greater that 120/min.

ACLS

  • Mechanical CPR devices may be considered, but manual CPR is still standard of care.
  • ECMO is being studied, but no RCTs to demonstrate effect on survival. May be considered in refractory arrest with a suspected reversible cause.
  • Vasopressin removed from cardiac arrest algorithm to streamline approach
  • The steroids, vasopressin, and epinephrine bundle may be considered but cannot be recommended at this time.
  • Lipid emulsion therapy may be considered for cardiac arrest due to drug toxicity.

ACS

  • Recommend use of two troponins and risk stratification tool to identify patients at low risk of MACE at 30 days.

Ultrasound in cardiac arrest

What is the predictive value of bedside transthoracic echo in predicting survival in cardiac arrest?

A 2012 systematic review by Blyth published in Academic Emergency Medicine reviewed 8 studies with the following pooled results:

Echo ROSC No ROSC
Cardiac contractility seen on echo 98 92
No cardiac contractility seen on echo 9 369

This gave a pooled -LR of absence of cardiac activity on echo to predict lack of ROSC of 0.17 and a +LR of presence of cardiac activity to predict ROSC of 4.26.

As not every study measured the same outcomes, this review could not provide an analysis of echo predicting survival to discharge.

As 2.4% of patients without cardiac activity achieved ROSC, echo alone should not be used to cease resuscitative efforts.

There is an ongoing multicenter trial which will hopefully provide more data to clarify the utility of echo in cardiac arrest.