Advanced Cardiovascular Life Support (ACLS) Practice Exam

If emergency medical responders cannot obtain a peripheral IV for a patient in cardiac arrest, what is the most preferred route for drug administration?

1. Intramuscular (IM)

2. Intraosseous (IO)

3. Subcutaneous (SC)

4. Central venous (CV)

The correct answer is: Intraosseous (IO)

In situations where emergency medical responders are unable to establish a peripheral intravenous (IV) line for a patient experiencing cardiac arrest, the intraosseous (IO) route is the preferred method for drug administration. This approach involves inserting a needle into the bone marrow, which provides immediate access to the vascular system. The IO route is particularly valuable during cardiac arrest because it allows for rapid infusion of medications, achieving systemic circulation akin to that of an intravenous line. Utilizing intraosseous access is effective because the bone marrow is highly vascular, permitting swift absorption of medications directly into the bloodstream. This is critical in the urgent context of cardiac arrest, where time is of the essence for delivering lifesaving drugs such as epinephrine or amiodarone. In contrast, intramuscular (IM) administration is slower in terms of absorption and is not ideal for resuscitation scenarios where immediate drug action is required. Subcutaneous (SC) administration also presents a delayed effect and is not suitable for urgent interventions. Central venous (CV) access is more invasive and typically requires specialized training or procedures that may not be feasible in pre-hospital settings, especially during emergencies. Therefore, in the context of cardiac arrest, intraosseous drug administration is preferred for its speed