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 atropine and all of its effects, including indications, precautions and contraindications, and adult dosages. At the end of this lesson, we provide a Word about the various routes of access for drug administration.
Atropine sulfate is an anticholinergic or anti-parasympathetic, sometimes referred to as a parasympatholytic drug. A parasympatholytic agent is any substance or activity that has the effect of reducing the activity of the parasympathetic nervous system.
Pro Tip #1: An anticholinergic agent is a substance that blocks the action of the neurotransmitter acetylcholine at synapses in the central and the peripheral nervous system. These agents inhibit parasympathetic nerve impulses by selectively blocking the binding of the neurotransmitter acetylcholine to its receptor in nerve cells.
The parasympathetic nervous system is often described as the rest and digest part of the autonomic nervous system. Atropine works by blocking this action.
The autonomic nervous system is a control system that acts mostly unconsciously as it regulates bodily functions, such as the heart rate, respiratory rate, pupillary response, digestion, urination, and arousal.
Atropine Indications
Now let's take a look at some indications for atropine.
Atropine should be your first choice of treatment of symptomatic sinus bradycardia, including 1st degree and 2nd degree type II AV nodal blocks.
Pro Tip #2: In heart transplant recipients, the vagus nerve is not surgically reattached to the donor heart. Because atropine increases heart rate by blocking vagal (parasympathetic) input to the heart, it is unlikely to be effective in these patients.
Atropine Precautions and Contraindications
There are a couple of precautions and contraindications when it comes to administering atropine.
It is well known that atropine use during pulseless electrical activity (PEA) and asystole usually has no therapeutic benefit. Also important to remember, is that atropine most likely will not affect type 2, 2nd degree or 3rd degree AV blocks or blocks in non-modal tissue.
Adult Dosage of Atropine
Let's take a closer look at the adult dose of atropine.
For bradycardia with or without acute coronary syndrome (ACS), administer 1 mg of atropine IV every 3 to 5 minutes or as needed. And make sure not to exceed a total dose of 0.04 mg/kg or a total of 3 mg.
Pro Tip #3: It's recommended to use a shorter dosing interval, such as every 3 minutes, and higher doses in severe clinical conditions.
For organophosphate poisoning, you may need to use 2 – 4 mg of atropine or higher to reverse the life-threatening symptoms of such a poisoning.
The good news, as it relates to administering atropine, is that giving the drug via the intraosseous (IO) route has been found to be just as effective as intravenous (IV) infusion for rapid delivery of the drug.
Pro Tip #4: Because large amounts of atropine may be required in patients with organophosphate poisoning, reconstitution of powdered atropine may be a viable option, especially when there is a mass casualty setting.
Warning: It's also important to remember to utilize your personal protective equipment when treating patients with organophosphate toxicity to reduce and prevent the risk of cross-contamination with other rescuers.
A Word About the Routes of Access for Drugs
In this Word, we'll look at the priorities of access routes along with some specifics concerning the intravenous route. In the following Word section in the dopamine lesson, we'll finish up by looking at both the intraosseous route and the endotracheal route, along with a little information on fluid administration.
Prioritizing Drug Access Routes
The obvious priorities during cardiac arrest are high-quality CPR and early defibrillation. While the insertion of an advanced airway and drug administration are of secondary importance.
While medications given during cardiac arrest — such as epinephrine and antiarrhythmics — can improve the likelihood of achieving ROSC and in some cases survival to hospital admission or discharge, no drug has been consistently shown to improve long-term neurologic outcomes after cardiac arrest. This is why high-quality CPR and early defibrillation remain the cornerstones of cardiac arrest management.
Historically in ACLS, healthcare providers have administered medications via the endotracheal route. However, endotracheal absorption of medications is poor and unpredictable which makes optimal drug dosing problematic. Because of this, endotracheal is not recommended.
Intravenous (IV) and Intraosseous Routes
A peripheral IV/IO will be preferred for medication and fluid administration unless central line access is already available. However, central line access isn't necessary during most resuscitation attempts.
Central line access could cause interruptions in CPR and complications during insertion, including vascular laceration, hematomas, and bleeding. Also, insertion of a central line in a non-compressible vessel is a relative, but not absolute, contraindication to fibrinolytic therapy in patients with acute coronary syndrome.
Establishing a peripheral line, by contrast, does not require an interruption of CPR. Medications take between 30 and 60 seconds to start working.
If a medication is administered via the peripheral venous route, administer it as follows:
- Administer the medication by bolus injection unless otherwise specified
- Follow the drug with a 20 mL bolus of IV fluid
- Elevate the extremity for about 10 to 20 seconds to facilitate the delivery of the medication into the central circulation
