Note: Your progress in watching these videos WILL NOT be tracked. These training videos are the same videos you will experience when you take the full ProACLS Recertification program. You may begin the training for free at any time to start officially tracking your progress toward your certificate of completion.
In this lesson, we'll go over the medication epinephrine and all of its effects, including indications, precautions and contraindications, and adult dosages.
Epinephrine, also commonly referred to as epi, is a chemical that narrows the blood vessels and opens the airways in the lungs. And it's also commonly known as adrenaline.
Adrenaline is a hormone that is secreted mainly by the medulla of the adrenal glands and functions primarily to increase cardiac output and to raise blood glucose levels.
Epinephrine is typically released during periods of acute stress and its effects are a built-in defense mechanism and what prepares an individual for either a fight or flight response. For this reason, it's also a primary medication for non-perfusing cardiac arrest in pediatric patients.
One common effect of epinephrine is reversing low blood pressure.
Epinephrine is a sympathomimetic drug. Sympathomimetic drugs mimic the effects of the sympathetic nervous system and are thus used to increase the heart rate and blood pressure. Drugs in this category are usually the synthetically produced equivalent to what is endogenous (naturally occurring) in the human body.
Epinephrine is also a naturally occurring catecholamine. It possesses positive alpha- and beta-adrenergic effects. Its alpha effects result in vasoconstriction, thus increasing the blood pressure. Its selective beta1 effects result in increased heart rate (positive chronotropy) and increased myocardial contractility (positive inotropy). While its selective beta2 effects cause a relaxation of bronchial smooth muscle (bronchodilation).
Now let's take a look at epinephrine indications.
Epinephrine is used in cardiac arrest arrhythmias such as V-Fib, pulseless V-tach, asystole, and pulseless electrical activity (PEA). Epinephrine can also be used in symptomatic bradycardia and for the treatment of severe hypotension.
Epinephrine can be administered after atropine as an alternative to infusing dopamine. It has also been established that epinephrine can be administered when external pacing and atropine fail and when bradycardia causes hypotension.
It's safe to administer epinephrine with phosphodiesterase enzyme inhibitors, and it's also an effective treatment for anaphylaxis.
Pro Tip #1: It's recommended that epinephrine be combined with large volumes of fluids, corticosteroids, and antihistamines.
Epinephrine has a few precautions and contraindications that we should note.
Care should especially be taken when administering epinephrine in cases where raising the patient's blood pressure and increasing their heart rate might cause myocardial ischemia, angina, and increase the demand for myocardial oxygen.
Pro Tip #2: It should be noted that high doses of epinephrine do not improve neurological outcomes or survival rates and may actually contribute to post-resuscitation complications like myocardial dysfunction.
In healthcare settings, we commonly see high doses of epinephrine treatment with poisoning and drug-induced shock.
Now let's look at the adult dosage of epinephrine.
Warning: Epinephrine is available in two concentrations and it's important to know when to use each, and to pay extra attention to which concentration you're actually using when administering epinephrine to patients.
The two available concentrations are 1:1000 and 1:10,000. And for cardiac arrest in adult patients, you should deliver via IV or IO at 1 mg or 10 ml of 1:10,000 every 3 to 5 minutes during resuscitation.
Follow each dose of epinephrine with 20 ml of normal saline as a flush. And elevate the patient's arm in which the medication was delivered for 10 to 20 seconds after the dose has been administered.
If you encounter a situation where there is no IV or IO access, epinephrine may be delivered via the endotracheal route at 2 to 2.5 mg diluted in 10 ml of normal saline.
Pro Tip #3: Higher doses of epinephrine – up to 0.2 mg per kg of body weight may be used for specific indications like beta-blocker or calcium channel blocker overdose.
If you're administering epinephrine as a continuous infusion, the initial rate is 0.1 to 0.5 mcg per kg per minute. An example of this would be if you're giving epinephrine to a patient weighing 90 kg, you'd give the patient between 9 and 45 mcg per minute and titrated to a positive patient response.
In cases of profound bradycardia or hypotension, deliver 2 to 10mcg per minute of epinephrine titrated to a patient response delivering a drip via an IV infusion. And add 1mg of epinephrine (or 1ml of 1:1000 solution) to a 250ml or 500ml of normal saline.
For treatment of anaphylactic shock, an epinephrine concentration of 1:1000 should be given at .01mg per kg of body weight via intermuscular delivery.