Vascular Access and Medication Administration in the Field

Vascular Access and Medication Administration in the Field

Establishing reliable vascular access and delivering medications accurately are two of the most consequential skills a paramedic performs. Errors in either area can cause serious patient harm. This lesson covers peripheral intravenous (IV) access, intraosseous (IO) access, and the correct technique for administering medications by multiple routes used in prehospital care.

Peripheral IV Access

Peripheral IV access allows you to deliver fluids and medications directly into the venous circulation. Before attempting venipuncture, gather all equipment, apply gloves, and assess the patient's arm for a suitable vein — the antecubital fossa, forearm, and dorsum of the hand are common sites. Apply a tourniquet two to four inches proximal to the intended site to distend the vein. Clean the skin with an alcohol swab using a circular motion from the center outward and allow it to dry completely; wet skin compromises aseptic technique.

Bevel the catheter-over-needle upward at a 10–30° angle and enter the skin just distal to the target vein, then advance until you see a blood flashback in the hub. Slide the catheter off the needle into the vein while simultaneously withdrawing the needle. Never re-advance a needle through a catheter — doing so can shear the catheter tip, creating a fragment that can embolize. Immediately dispose of the needle in a sharps container. Attach IV tubing primed with normal saline, release the tourniquet, and open the flow to confirm patency. Secure the site with tape or a commercial dressing and document the catheter gauge, site, date, time, and number of attempts.

Use the largest catheter that the clinical situation and the vein support. For fluid resuscitation, a larger gauge (14–16 G) moves fluid faster. For medication infusions in stable patients, 18–20 G is typical. Smaller gauges (22–24 G) are used in pediatric patients or fragile veins.

Intraosseous Access

When IV access cannot be established rapidly and the patient's condition is critical, IO access provides an alternative route that reaches the systemic circulation within seconds. The proximal tibia is the most commonly used site in adults and children; the proximal humerus and sternum are alternatives on some devices. IO medications and fluids reach central circulation at rates comparable to peripheral IV.

Indications: inability to establish IV access in a time-critical patient, cardiac arrest, severe shock, or altered level of consciousness preventing cooperation.

Contraindications: fracture at or proximal to the intended site, previous IO in the same bone within 24 hours, infection overlying the site, or a bone condition (such as osteogenesis imperfecta) that increases fracture risk.

After site identification and skin preparation, use a commercial battery-powered IO drill to insert the needle with controlled pressure until you feel a sudden decrease in resistance as the needle enters the medullary cavity. Remove the stylet, attach a syringe, and attempt to aspirate marrow (aspiration may not always be possible — absence alone does not confirm misplacement). Flush with normal saline; absence of swelling and free flow confirm placement. Secure the device and note that IO infusions can be painful in conscious patients — lidocaine may be administered IO for analgesia prior to flushing per local protocol.

Six Rights of Medication Administration

Before administering any medication by any route, verify all six rights:

1. Right patient — confirm patient identity

2. Right drug — read the label three times (when you pick it up, when you draw it up, when you administer it)

3. Right dose — calculate and confirm

4. Right route — match the order (IV push, IV drip, IO, IM, intranasal)

5. Right time — administer at the ordered interval

6. Right documentation — record immediately on the PCR

Routes of Administration

IV push: Draw the calculated dose into a syringe. Cleanse the medication port, inject over the time specified in the order or protocol, and flush with normal saline.

IV drip: Add the drug to a compatible IV bag and calculate the drip rate in drops per minute or program an infusion pump. Label the bag with drug name, concentration, date, and time.

Intraosseous (IO): The same volume and dose as IV. Flush the line before and after to ensure the drug clears the needle.

Intramuscular (IM): Select a site with adequate muscle mass (deltoid, vastus lateralis). Insert the needle at 90° and aspirate first — if blood returns, withdraw and select a new site. Inject slowly and withdraw the needle.

Intranasal (IN): Use a mucosal atomizer device (MAD) attached to a syringe. Divide the dose between both nares and administer by rapid plunger depression. The IN route is especially valuable for pediatric patients and for drugs absorbed well across nasal mucosa.

Safety Essentials

• Maintain aseptic technique throughout every procedure to prevent infection.
• Inspect every medication vial for clarity, color, expiration, and correct label before drawing up.
• Perform dose calculations before, not after, drawing up a drug; have a partner verify when policy requires it.
• Never recap needles by hand — use a one-handed scoop technique or a device.
• After any sharps use, dispose immediately in a puncture-resistant container.
• Document every medication and access attempt on the PCR — incomplete documentation is an error.
• IO needle dislodgment can cause compartment syndrome; monitor the limb distal to the site.