Intravenous (IV) Therapy Technique

IV therapy delivers liquid directly into a vein, intermittently or continuously (a continuous infusion is an IV drip). It is the fastest route for fluids and medications, a cornerstone of modern care.

What is Intravenous Therapy?

IV therapy infuses liquids, medications or nutrients, directly into a vein for rapid distribution throughout the body.

Purposes of IV Therapy

• Maintain or restore fluid balance, rehydrating dehydrated patients.
• Correct electrolyte imbalances quickly for proper cellular function.
• Deliver medications straight into the bloodstream for rapid or controlled effect.
• Provide hydration for patients who cannot drink.
• Emergency situations, for lifesaving rapid delivery of medications and fluids.
• Total parenteral nutrition (TPN) for patients who cannot eat or absorb nutrients.
• Blood transfusions for significant blood loss or hematologic conditions.

Types of Intravenous Fluids

Two types are used for IV drips: crystalloids and colloids.

See also: IV Fluids and Solution Cheat Sheet

Crystalloids

Crystalloids are aqueous solutions of mineral salts or other water-soluble molecules. The most common is normal saline, sodium chloride at 0.9% concentration, close to the concentration in blood (isotonic). Ringer's lactate or Ringer's acetate is another isotonic solution for large-volume replacement. For patients at risk of low blood sugar or high sodium, 5% dextrose in water (D5W) is often used. Fluid choice also depends on the chemical properties of the medications given, and IV fluids must always be sterile. Crystalloids are used for rehydration and electrolyte replacement.

Colloids

Colloids contain larger insoluble molecules such as gelatin; blood itself is a colloid. They preserve a high colloid osmotic pressure in the blood, while crystalloids decrease it through hemodilution, and crystalloids are much cheaper. Because colloids' large particles are not easily absorbed into the vascular bed, they are used to replace lost blood, maintain blood pressure, and expand volume.

Steps in Intravenous Therapy

Three phases: pre-catheterization, catheterization, and post-catheterization.

Pre-Catheterization

1. Review the Physician's Order

The order should include:

• Type of solution to be infused.
• Route of administration.
• Medication dosage, the exact amount of any added medication, per hour or as a 24-hour total volume.
• Rate of infusion.
• Duration of infusion.
• Physician's signature to authorize the procedure.

2. Observe Hand Hygiene

• Visible contamination: wash with non-antimicrobial or antimicrobial soap and water when hands are visibly dirty or contaminated with blood or body fluids.
• No visible soiling: use an alcohol-based hand rub in all other clinical situations.
• Patient contact: decontaminate hands before direct contact.
• Nail hygiene: avoid artificial fingernails or extenders with high-risk patients.

3. Gather Equipment

• Verify fluid expiration.
• Inspect container integrity. Glass: hold up to light for cracks, clarity, particulate contamination, and expiration. Plastic: squeeze to check for pinholes, clarity, particulate contamination, and expiration.
• Inspect the administration set for appropriateness.
• Choose vented or non-vented based on the fluid.
• Gather venipuncture and dressing supplies:
  • Catheter: common sizes 22 gauge, 20 gauge, or 18 gauge.
  • Dressing: gauze or transparent semi-permeable membrane (TSM).
  • Tape: 1-inch paper tape.
  • Prepping solution: suitable antiseptic.
  • Gloves: sterile.
  • Gauze: 2×2 sterile pads.

4. Patient Assessment and Psychological Preparation

• Introduce yourself and verify identity.
• Provide privacy.
• Explain the procedure, noting venipuncture may cause brief discomfort but none once the solution flows.
• Evaluate preparedness by discussing the procedure before assessing veins.

Patient information to consider: medical diagnosis; chronic diseases that raise complication risk; vasovagal reactions (history of fainting at venipuncture or blood); previous vascular access devices; whether the patient will go home with the catheter; and cultural or language barriers (take extra time, speak clearly, use pictures or an interpreter).

Physical assessment: evaluate both arms and hands; choose the lowest, best site for the catheter size and therapy; check for allergies to tape, povidone-iodine, or latex; record baseline vital signs; assess skin turgor for hydration; evaluate bleeding tendencies; assess for disease or injury to the arms; and determine vein condition.

5. Site Selection and Vein Dilation

Factors to consider:

• Type of solution: hypertonic solutions and medications can irritate the vein.
• Condition of vein: choose a soft, straight, bouncy vein; avoid veins that feel like a cat's tail and those near previously infected areas.
• Duration of therapy: choose a vein that can support IV therapy for 72–96 hours.
• Catheter size: use the smallest gauge possible for proper hemodilution.
• Patient age: elderly and pediatric patients need extra assessment.
• Patient activity: for patients using crutches or walkers, place the catheter above the wrist.
• Disease or surgery: avoid areas with poor vascular return (mastectomy, stroke).
• Shunts or grafts: do not use limbs with patent grafts or shunts for dialysis.
• Anticoagulation: use minimal tourniquet pressure and care removing dressings.
• Allergies: avoid iodine or latex if the patient is allergic.

Vein dilation techniques:

• Tourniquet: latex or non-latex, placed 6–8 inches above the venipuncture site, adjusted for blood pressure.
• Gravity: position the extremity lower than the heart.
• Fist clenching: have the patient open and close the fist.
• Vein tapping: gently flick the vein with thumb and second finger to release histamines and dilate it; avoid slapping.
• Warm compresses: apply for a maximum of 10 minutes; do not microwave the compress.
• Blood pressure cuff: inflate to 30 mmHg, effective for fragile veins.
• Multiple tourniquet technique: use 2 to 3 tourniquets, one high on the arm for 2 minutes, a second at mid-arm below the antecubital fossa, and a third if needed.

Tips for selecting veins: choose smooth, pliable veins with well-spaced valves; work distal to proximal; avoid bumpy veins (usually thrombosed or valvular); assess sclerotic veins carefully (common with drug addiction); and consult dialysis patients, who often know their best veins.

Catheterization

1. Needle Selection

Catheters come in gauges; smaller numbers mean thicker catheters, which infuse faster but hurt more on insertion. Inspect the tip for integrity and limit venipuncture attempts to two.

• 14G (orange): massive trauma.
• 16G (gray): trauma, surgery, or multiple large-volume infusions.
• 18G (green): blood transfusions or large-volume infusions.
• 20G (pink): multi-purpose for medications, hydration, and routine therapy.
• 22G (blue): most chemo infusions, small veins, elderly, or pediatric patients.
• 24G (yellow): very fragile veins, elderly, or pediatric patients.

2. Don Your Gloves

Gloves are mandatory; blood contact risk is high, especially for less experienced staff. Add face and eye protection and a gown if splatter risk is high. Maintain hand hygiene before donning sterile gloves and replace compromised gloves immediately.

3. Site Preparation

• Apply antimicrobial solution from the center outward in a circular motion, covering 2-3 inches for at least 20 seconds, with enough friction to clean.
• Avoid shaving, which causes micro-abrasions; remove hair with scissors or clippers.
• Avoid depilatories due to allergic reaction risk.
• Do not apply 70% isopropyl alcohol after povidone-iodine, which negates the iodine's antimicrobial effect.
• Cleanse with one of: 2% chlorhexidine gluconate (preferred), iodophor (povidone-iodine), 70% isopropyl alcohol, or tincture of iodine 2%.

4. Insertion of Catheter into Vein

1. Position the extremity in a dependent position (lower than the heart), using gravity to distend the veins for easier insertion.

2. Apply the tourniquet firmly 15 to 20 cm (6 to 8 inches) above the venipuncture site, tight enough to occlude venous flow but not arterial (confirm a palpable radial pulse). Tell the patient it will feel tight. If the vein is not palpable, use vein stimulation (massage or stroke distal to the site, have the patient clench and unclench the fist, lightly tap the vein) or a warm compress (remove the tourniquet and apply a warm, moist towel for 10-15 minutes to dilate the vessels; repeat as needed).

3. Put on clean gloves and clean the site with a topical antiseptic swab from the center outward in a circular motion for several inches. Let it dry to enhance efficacy. If using povidone-iodine, keep it in contact for at least one minute. Check for antiseptic allergies first.

4. Stabilize the vein by pulling the skin taut below the entry site with your nondominant hand, which keeps the vein from rolling.

5. Insert the catheter (over-the-needle) at a 15- to 30-degree angle, bevel up, smoothly through the skin into the vein. Avoid jabbing or quick thrusts, which rupture veins and cause pain.

6. Advance the catheter. Once blood appears in the lumen or resistance disappears, lower the angle until nearly parallel with the skin and advance about 1 cm further, so the catheter, not just the needle, sits in the vein.

7. Advance the catheter hub, keeping the needle steady, until the hub is at the venipuncture site.

8. Release the tourniquet and apply pressure on the vein proximal to the catheter to reduce oozing, stabilizing the hub with the nondominant thumb and index finger.

9. Remove the protective cap from the distal tubing, keeping it sterile and ready to attach.

10. Remove the needle, engaging the safety device, and immediately attach the infusion tubing to the hub to maintain a closed system.

11. Initiate the infusion and tape the catheter using the "U" method or the manufacturer's instructions, with three strips of tape (about 3 inches long).

12. Dress and label the site and tubing per agency policy, including the date the set must be changed and the date, time, type, and length of the catheter.

13. Document the procedure and all relevant assessments.

5. Catheter Stabilization and Dressing Management

1. Tape the catheter using the U, H, or Chevron method (or the manufacturer's instructions), with three strips about 3 inches long, to prevent displacement.
2. Loop and secure the tubing with tape, so its weight or patient movement does not pull on the catheter.
3. Dress the site and tubing per agency policy to protect against infection and allow monitoring.

Types of dressings:

• Gauze with tape: traditional, good protection.
• Transparent semipermeable (TSM): allows continuous visualization for signs of infection.

Standards of practice:

• Gauze dressings: change every 48 hours on peripheral sites.
• Non-occlusive adhesive bandage strips: do not use in place of proper dressings.
• TSM dressings: change when the catheter is changed.

Post-Catheterization

1. Labeling

• Insertion site: date and time of insertion, type and length of catheter, and the nurse's initials.
• Administration set: label per agency policy, including the change date.
• Solution container: place a time strip on all parenteral solutions and clearly label any additives.

2. Equipment Disposal

• Needles and stylets: dispose of in non-permeable, tamper-proof containers.
• Paper and plastic equipment: dispose of in a biohazard container.

3. Patient Education

• Movement and mobility limitations to prevent dislodging the catheter.
• Alarms: explain all alarms if an Electronic Infusion Device (EID) is used.
• When to seek assistance: call if the site becomes tender, sore, red, or swollen, signs of infiltration.
• Monitoring schedule: the site will be checked every shift.

4. Rate Calculation

• Verify infusion flow per the physician's orders and patient needs.
• Adjust and confirm the rate before leaving, to ensure correct dosage.

5. Documentation

• Start of infusion: exact date and time.
• Venipuncture details: gauge and length of the device, name and location of the vein, and number and location of attempts.
• Solution information: amount used, additives, and container number.
• Flow rate.
• Needle or catheter details: type, length, and gauge.
• Dressing applied.
• Patient response, noting any reactions or complications.
• Nurse's signature.