Become familiar with these new cardiac drugs
There are many changes in pharmacology of resuscitation outlined in new guidelines from the Dallas-based American Heart Association (AHA), says Rebecca L. Stark-Johnson, CRNA, APNP, anesthesia manager at Fort Atkinson (WI) Memorial Health Services, and a regional faculty instructor for the AHA’s Advanced Cardiac Life Support (ACLS) program.
Here are several drugs and the changes in recommended indications and dosages, according to the guidelines:
• Intravenous amiodarone.
The guidelines add amiodarone as an alternative to lidocaine for persistent ventricular fibrillation, says John M. Field, MD, FACC, FACEP, associate professor of medicine and surgery at Pennsylvania State University College of Medicine in Hershey, and ACLS science editor at the AHA.
Amiodarone has been added to the list of recommendations for the initial treatment of stable wide-complex tachycardia, reports Darlene Bradley, RN, MSN, MAOM, CCRN, CEN, director of emergency/ trauma services at UCI Medical Center at University of California-Irvine.
Use caution in selection the correct drug, says Bradley. "Amrinone or adenosine might be mistakenly selected."
Here are the uses and dosages of the three drugs:
— Adenosine is used to terminate rapid supraventricular rhythms, and the dose is in 6-mg increments and doubled in two minutes of the rhythm persists.
— Amrinone is given for congestive heart failure, and the dosage is 0.75 mg/kg over 10-15 minutes.
— Amiodarone is used to treat rapid atrial and ventricular arrhythmias. The drug is used for rate control. It is given in 300 mg doses for arrest, and smaller doses for arrhythmias.
All three drugs are given intravenously, but they will not be given together, Bradley notes. "Because they all begin with the letter A,’ you should be careful in selecting the correct drug," she urges. "Taking the written order to the medication room may prevent errors in drug selection from occurring."
Amiodarone and procainamide are recommended as alternatives to lidocaine for the initial treatment of hemodynamically stable wide-complex tachycardia, especially in patients with compromised cardiac function, notes Stark-Johnson.
Practitioners are urged to try one drug, stresses Mary Fran Hazinski, RN, MSN, FAAN, senior science editor for the American Heart Association’s (AHA’s) emergency cardiovascular care programs and clinical specialist in the division of trauma in the departments of surgery and pediatrics at Vanderbilt University Medical Center in Nashville, TN.
"Use of a combination of several antiarrhythmics would be pro-arrythmic in the presence of decreased myocardial infarction," she warns.
• Lidocaine.
This drug has undergone a change in view, says Stark-Johnson. "Lidocaine remains acceptable as an antiarrhythmic for use in the treatment of shock refractory ventricular fibrillation and pulseless ventricular tachycardia, but the evidence supporting its efficacy is poor," she explains.
Lidocaine remains in the guidelines as an indeterminate recommendation, says Bradley. "This indicates that there is evidence to support the practice, but that current research is insufficient to support a class recommendation."
• High-dose epinephrine.
The recommendations have changed for the vasoconstrictor epinephrine. High-dose epinephrine has not been shown to be effective as previously thought, says Bradley. "Post-resuscitation complications have been found to be present when escalating doses of the drug have been given," she adds.
High-dose epinephrine has not been beneficial, Field notes. "When incremental [1-3-5 mg] doses or cumulative high doses are given, neurologic outcome may be worse," he warns.
A single high dose of epinephrine has not been shown to be either beneficial or harmful, says Field. "There is no change in the recommendation of the standard 1-mg dose," he says. "A high single dose can be given at the discretion of the provider when the standard dose fails. However, incremental or cumulative high doses are not recommended."
The research has not yet shown that routine use of initial and repeated or escalating doses of epinephrine can improve survival in cardiac arrest, says Stark-Johnson. "There is some troublesome evidence that patients that receive high dose epinephrine have more post-resuscitation complications than survivors that received the standard dose," she notes.
• Vasopressin.
The new guidelines add vasopressin as an alternative to the first dose of epinephrine in the pulseless ventricular tachycardia/ventricular fibrillation algorithm, says Field. "Vasopressin appears promising."
You may now consider vasopressin for promoting spontaneous circulation in full arrest victims, says Bradley. "It can now be substituted for epinephrine," she says.
Vasopressin, the natural substance antidiuretic hormone, becomes a powerful vasoconstrictor
when used at much higher doses than normally present in the body, says Stark-Johnson. "It possesses positive effects that duplicate the positive effects
of epinephrine, but does not duplicate the adverse effects," she says.
Vasopressin may be an equivalent agent to epinephrine for promoting return of spontaneous circulation in cardiac arrest, notes Stark-Johnson. "Vasopressin 40 U IV not repeated may be substituted for epinephrine as an alternative class IIB agent [which indicates that it is acceptable to use and has fair-to-good evidence supporting its usage]," she says. "The lower adverse side effects profile may be the major reindication for vasopressin."
• Bretylium.
This drug is no longer included the treatment plan, says Bradley. "Bretylium was used as a third-line drug in the treatment of ventricular fibrillation or pulseless ventricular tachycardia," she notes.
Bretylium became problematic when the supplier was unable to produce the quantities needed, reports Bradley. "There was concern that if the drug was kept within the guidelines, the manufacturer could not meet the demands," she says.
Bretylium remains a class IIB recommendation, but it is no longer recommended in the guidelines, Bradley explains. "Additionally, bretylium has a very high incidence of side effects," she cautions. "Hypotension caused by this drug in the post-resuscitation phase of care is a major concern."
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content