Summary of Intravenous Cannulation Procedure Guide

## Introduction Peripheral IV cannulation requires choosing an appropriate vein and preparing the site carefully. Good site selection and preparation reduce complications, improve patient comfort, and increase the chance of first-attempt success. > Definition: A suitable peripheral IV site is a superficial vein that is visible or palpable, straight enough to accept a cannula, free from infection or injury, and located so it will be comfortable and functional for the patient. ## Step-by-step approach to identifying a suitable vein ### 1. Positioning the arm 1. Ask the patient to sit or lie so the arm can be comfortably extended. 2. Ensure the planned area for cannulation is well exposed and supported. Practical tip: Use a small pillow or rolled towel under the elbow to stabilize the arm if needed. ### 2. Inspect the arm - Look for visible veins before applying a tourniquet when possible; a vein that is visible without a tourniquet is often a reliable choice. Did you know a clearly visible superficial vein often indicates a larger, more stable vessel suitable for cannulation? ### 3. Discuss laterality and patient preference - Ask the patient which arm they prefer. - Prefer the non-dominant arm when clinically appropriate to reduce interference with daily activities. Practical example: For a patient who types frequently, choose the left arm if they are right-handed and there are suitable veins on both sides. ### 4. Apply the tourniquet - Place the tourniquet approximately 4–5 finger widths (about 6–8 cm depending on finger size) above the planned puncture site. - Reassess vein visibility and palpability after the tourniquet is applied. ### 5. Palpate the vein - Feel for a vein that is "springy" and compressible but returns to shape when released. - Prefer a straight segment to accommodate the cannula. - Have the patient gently clench and unclench their fist or tap the vein to help it fill and become more palpable. - Avoid veins across joints (near wrists or antecubital crease) to reduce the chance of dislodgement with movement. > Definition: A springy vein is one that compresses under light pressure and quickly refills, indicating good venous tone and flow. ### Things to avoid when choosing a site - Areas where two veins join (valves may be present and obstruct cannula advancement). - Limbs with contraindications: arterio-venous fistula, lymphoedema, recent mastectomy on that side, or prior surgical/vascular procedures. - Skin that is broken, bruised, inflamed, or infected (cellulitis). Table: Common site choices and considerations | Site region | Advantages | Disadvantages | |---|---:|---| | Dorsal hand veins | Easily visible, distal (less restrictive) | More mobile and prone to phlebitis, smaller caliber | | Forearm (mid- to distal) | Good for longer dwell times, less movement | May be deeper and harder to palpate | | Wrist/antecubital fossa | Large veins, easy access | High movement area, increased dislodgement risk | ### 6. Skin cleaning before cannulation 1. Clean the chosen site with an alcohol swab for 30 seconds using outward circular strokes starting from the center and covering at least a 5 cm radius. 2. Allow the site to air dry completely for about 30 seconds. 3. Do not touch the cleaned site afterward; if touched, repeat cleaning. Practical tip: If the patient is cold and veins are hard to find, warm the forearm for several minutes with a warm compress before applying the tourniquet. Fun fact: Warming the limb increases local blood flow and can make veins more prominent, improving cannulation success. ## Visual cues (descriptive) - Inspect for a suitable vein: look for straight, visible superficial veins running along the dorsum of the hand or forearm. - Apply tourniquet: place it proximal to the intended site to engorge veins. - Palpate the vein: run your finger along the vessel to assess springiness and direction. - Clean the site: use vigorous 30-second alcohol swab motion from center outward; al