5.5 IV/IO Access and Medication Safety
Key Takeaways
- IV or IO access allows ACLS medications without stopping CPR.
- IO access is appropriate when IV access is not quickly available in an arrest or critical emergency.
- Medication timing should be assigned to a team member and announced clearly.
- Avoid stacking incompatible or duplicate antiarrhythmics without a clear indication.
5.5 IV/IO Access and Medication Safety
Access and medication safety are practical ACLS skills. The code leader must keep drug timing organized while preserving compression quality and avoiding avoidable medication errors.
Current official baseline
The adult advanced life support guidance covers cardiac arrest rhythms, defibrillation, airway decisions, drugs, peri-arrest tachycardia and bradycardia, and termination decisions. Use the official AHA 2025 Adult Advanced Life Support Guidelines page when your course materials or training-center instructions differ from third-party summaries: AHA 2025 Adult Advanced Life Support Guidelines.
What you need to know
| Decision point | What to do |
|---|---|
| Access priority | During arrest, obtain IV or IO access while CPR continues. Do not stop compressions for routine access attempts. |
| IO use | IO access is a fast route when peripheral IV access is delayed or difficult. It is especially useful in arrest scenarios. |
| Closed-loop meds | Medication orders should include drug, dose, route, and timing. The receiver repeats the order and confirms completion. |
| Safety | Track total doses, rhythm indication, and patient response. Avoid mixing stable tachycardia medications with arrest medications by habit. |
How this shows up on BLS/ACLS questions
BLS and ACLS items usually test priority. Read the patient state first: age, pulse status, breathing status, rhythm, stability, and number of rescuers. Then choose the action that protects perfusion, oxygenation, defibrillation timing, or the correct algorithm branch. If an answer sounds advanced but delays CPR, shock delivery, ventilation, or an urgent stability intervention, it is usually a distractor.
Scenario anchor
During VF arrest, the leader says, "Give epinephrine 1 mg IV now and tell me when it is in." The nurse repeats the order, administers it, and confirms. That is medication closed-loop communication.
Common traps
- Starting multiple IV attempts while no one compresses.
- Losing track of when epinephrine was last given.
- Using a drug because it is familiar rather than because the rhythm pathway calls for it.
Study action
Write this section as a one-line rule in your own words, then test it with mixed questions from the BLS/ACLS practice bank. Do not review only the matching topic. Mix it with nearby branches so you can tell when the rule applies and when it does not. For example, compare respiratory arrest with a pulse against pulseless arrest, or compare unstable tachycardia against VF/pVT arrest. The exam rewards that discrimination more than memorizing isolated facts.
Which route of drug administration is preferred during cardiac arrest when IV access cannot be rapidly established?
A patient with stable monomorphic ventricular tachycardia (VT) is being treated pharmacologically. What is the preferred drug?