# Peripheral Intravenous Cannulation

## Overview

This module describes how to cannulate a peripheral vein. The terms ‘cannula’ and ‘catheter’ are sometimes used interchangeably; however, for the purpose of this application, ‘cannula’ refers to the needle/stylet and plastic sheath combined and ‘catheter’ refers to the sheath only.

## Indications

## Contraindications

## Patient information and consent

Always verify your patient’s identity and obtain informed consent before proceeding.

### How do I explain this procedure?

“I need to put up a drip, which is a small plastic tube in your vein. We use it to give you fluids or medicine.”

### What can my patient expect?

“You may feel a sharp sting when I insert the needle, but it should stop hurting after that.”

“The plastic tube may stay in your arm for a few days, but the metal needle will be removed immediately.”

### What is my patient’s role?

“Keep as still as possible while I insert the drip. Let me know if you have any allergies or a bleeding tendency, or use blood thinners. Fearing blood or needles is normal, but tell me if you have fainted from it. If the area around the drip gets tender, swollen or red or it starts bleeding, call a doctor or nurse immediately.”

## Preparation

Prepare a trolley with equipment.

### Documentation

### Equipment

## Site & Positioning

Straight, visible veins on forearms of the non-dominant limbs are preferred. Other sites include veins on the wrist, the backs of the hands and, the antecubital fossa, feet, and the jugular vein as a last resort. Avoid insertion over a joint. Ensure good lighting. Do not cannulate arteries with this technique.

## Procedure

Follow medical asepsis with non-sterile gloves.

## Troubleshooting

I can’t find a vein.

Check each hand. Apply heat to the skin and tap on the site to help raise the vein. Ask the patient to make a fist. Inflate the cuff of a sphygmomanometer between systolic and diastolic to create pressure in the veins. If not successful, try the antecubital fossa and other sites. Consider asking for help.

I’ve achieved flashback but the catheter won’t advance.

This usually means you’re not fully in the vein. Gently advance the stylet another millimeter and look again for flashback. Try advancing the catheter again. Try twice and if still unsuccessful, choose another site.

The site is swelling or bruising immediately.

This usually happens when you’ve gone right through the vein (“blowing” it). Get a fresh cannula and try a different site.

The vein is moving under the skin.

Make sure you anchor the skin firmly and ‘stab’ the vein before it can escape.

I am definitely in the vein, but now the catheter feels stuck.

You may have hit a valve in the vein. Try flushing the catheter with saline while advancing. The flush might open the valve so you can push through. Otherwise, if the catheter flushes well, secure it right there. Be aware that these half-inserted catheters often dislodge and don’t flow as well as when fully advanced.

I am unsuccessful after 3 attempts.

Ask help from a colleague or senior healthcare professional.

## Risks

## References