Peripheral Intravenous Cannulation and Blood Sampling
Introduction
Peripheral intravenous (IV) cannulation is one of the most common clinical procedures performed in healthcare settings. It involves inserting a cannula into a peripheral vein to establish venous access, which then allows for administration of fluids, medications, blood products, and nutritional support. Additionally, the IV access often serves as the primary route for blood sampling. This document provides a comprehensive overview of peripheral IV cannulation, including indications, contraindications, equipment, technique, and potential complications.
Indications
Peripheral IV cannulation is indicated for various clinical scenarios, including:
- Administration of medications that must be delivered intravenously
- Fluid resuscitation and hydration therapy
- Blood product transfusion
- Parenteral nutrition
- Emergency access for rapid medication administration
- Repeated blood sampling
- Maintenance of a route for emergency medications
- Contrast administration for imaging procedures
Contraindications and Precautions
IV cannulation should be avoided in certain areas and situations:
- Avoid areas with infection, inflammation, or cellulitis
- Avoid limbs with compromised circulation (e.g., due to trauma, stroke, or mastectomy)
- Avoid areas with known thrombosis
- Avoid veins that are sclerosed or fragile
- Be cautious with patients who have bleeding disorders or are on anticoagulant therapy
- Consider alternatives for patients with a history of multiple failed attempts
Patient Preparation
Proper patient preparation is crucial for successful IV cannulation:
- Explain the procedure to the patient, including benefits and potential discomfort
- Obtain informed consent
- Verify patient identity using two patient identifiers
- Assess the patient's medical history, allergies, and current medications
- Select an appropriate vein by examining both arms
- Consider using techniques to improve vein visibility (e.g., warmth, tourniquet, gravity)
- Gather all necessary equipment before beginning the procedure
Equipment Needed
The following equipment is typically required for peripheral IV cannulation and blood sampling:
- Appropriately sized IV cannula (commonly 14-22 gauge, depending on clinical need)
- Tourniquet
- Antiseptic solution (e.g., chlorhexidine, alcohol)
- Sterile gloves
- Sterile gauze or dressing
- Securement device or tape
- Syringe with saline flush
- Clean gloves
- Vacuum blood collection tubes (if blood sampling is required)
- Blood collection needles or vacutainer holder
- Labels for patient identification
- Sharps container
- Personal protective equipment (PPE) as indicated
Procedure for Peripheral IV Cannulation
Step 1: Site Selection
Select the appropriate vein by visual inspection and palpation. Common sites include the dorsal hand veins, forearm veins, and antecubital fossa veins. Choose the most distal vein possible to preserve more proximal sites for future cannulation if needed.
Step 2: Preparation
Apply the tourniquet approximately 5-10 cm above the chosen insertion site to engorge the vein. Clean the site thoroughly with the antiseptic solution, working in a circular motion from the center outward and allowing the solution to dry completely.
Step 3: Insertion
Put on clean gloves. Stabilize the vein by applying gentle traction below the insertion site. Hold the cannula with the bevel facing upward at a 15-30 degree angle. Insert the needle through the skin and into the vein, looking for a "flashback" of blood in the cannula chamber.
Step 4: Cannula Advancement
Once flashback is observed, advance the cannula slightly further into the vein while keeping the needle stationary. Then, thread the catheter forward into the vein while simultaneously withdrawing the needle until the catheter is completely inserted.
Step 5: Removal and Tourniquet Release
Release the tourniquet before attaching the IV tubing or flush. Apply gentle pressure to the vein above the cannula tip to prevent bleeding during needle removal.
Step 6: Securement and Connection
Attach the IV tubing or perform the initial saline flush to confirm patency. Secure the cannula with dressing and tape. Label with date, time, size of cannula, and the healthcare provider's initials.
Blood Sampling Technique
Step 1: Preparation
Prepare the collection tubes in the order of draw to prevent cross-contamination between additives. Typically the order is: blood culture tubes, coagulation tubes, serum tubes, heparin tubes, EDTA tubes, and fluoride tubes.
Step 2: Withdrawal
If using an existing IV cannula, ensure it is patent by flushing with saline. Attach the blood collection system and withdraw the required amount of blood, filling each tube to the appropriate level.
Step 3: Post-Collection
Gently invert tubes as required to mix with additives. Label tubes immediately with patient information and collection time/flask. Dispose of used needles in the sharps container.
Step 4: Flush and Secure
Flush the IV cannula with saline to re-establish patency after blood sampling. Ensure proper securement of the IV line.
Potential Complications
Despite proper technique, complications may occur with peripheral IV cannulation:
- Infiltration/Extravasation: Leakage of IV fluid into surrounding tissue, potentially causing swelling, pain, or tissue damage with certain medications.
- Phlebitis: Inflammation of the vein, characterized by redness, warmth, tenderness, and sometimes a palpable cord along the vein.
- Infection: Local cellulitis or more serious systemic infection can occur if proper aseptic technique is not maintained.
- Hematoma: Localized collection of blood outside the blood vessels, usually resulting from puncture through the vein.
- Nerve Injury: Accidental puncture or compression of nerves can cause pain, paresthesia, or rarely, permanent damage.
- Thrombophlebitis: Inflammation associated with clot formation in the vein.
- Thrombosis: Formation of a blood clot, which can lead to venous obstruction and potential for embolization.
- Cellulitis: Spreading infection of the skin and subcutaneous tissues.
Best Practices and Tips
- Use ultrasound guidance for patients with difficult venous access
- Consider using local anesthetic for patients with high anxiety or multiple previous attempts
- Rotate IV sites frequently (every 72-96 hours) to reduce phlebitis risk
- Document size, location, and appearance of the site regularly
- Maintain proper hand hygiene throughout the procedure
- Be prepared to attempt at another site if unsuccessful after two attempts
- Consider warming the site for 5-10 minutes to improve vein visibility
- Avoid areas of joint flexion when possible to reduce kinking
- Use a smaller gauge cannula when larger veins are not available
- For blood sampling, avoid drawing from an arm with a running IV infusion if possible
Conclusion
Peripheral intravenous cannulation and blood sampling are fundamental skills in clinical practice. These procedures provide essential access for therapy and diagnostic purposes. Proper technique, patient preparation, and ongoing assessment of the IV site are critical to minimize complications and maximize patient comfort. Healthcare practitioners should maintain competence in these procedures through regular practice and staying updated on current best practices and guidelines.
References
- Franz B, Zorzela L, Ospina MB. Peripheral IV cannulation: an evidence-based approach to improving technique and patient outcomes. Int J Nurs Pract. 2020;26(5):e12860.
- Infusion Nurses Society. Infusion therapy standards of practice. J Infus Nurs. 2021;44(1S):S1-S130.
- Guidelines for the Prevention of Intravascular Catheter-Related Infections. Centers for Disease Control and Prevention. 2017.
- Timmerman A. Peripheral intravenous cannulation: a review of the literature. J Infus Nurs. 2022;45(1):34-43.
- Royal College of Nursing. Standards for Infusion Therapy. London: RCN Publishing; 2018.
Peripheral Intravenous Cannulation And Blood Sampling and Reference File Download Link
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