When peripheral access is not possible in an emergency, what is the next step?

In situations where peripheral access is challenging or impossible, intraosseous access is the preferred alternative for rapid vascular access, especially in emergency scenarios. This technique involves delivering fluids or medications directly into the marrow of a bone, which allows for a quick and effective way to achieve systemic circulation.

Intraosseous access is particularly useful in pediatric patients, as their small veins can be difficult to catheterize, especially during critical situations where every moment counts. The bone marrow is highly vascular, so administering fluids or drugs here can lead to immediate absorption into the bloodstream, supporting vital functions until definitive intravenous access can be established.

The other methods mentioned do not provide the rapid and effective solution needed in emergent situations. Centrally-placed IV lines require more time and expertise to establish, which can be critical in acute care. Subcutaneously implanted access is not appropriate in emergencies, as it is used for planned long-term medication administration and not for rapid interventions. An emergency cricothyrotomy addresses airway issues rather than vascular access, making it an unsuitable choice when the primary concern is the delivery of fluids or medications.