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Intravenous (IV) Therapy Technique

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By Gil Wayne BSN, R.N.

Intravenous therapy or IV therapy is the giving of liquid substances directly into a vein. It can be intermittent or continuous; continuous administration is called an intravenous drip.

The word intravenous simply means “within a vein”, but is most commonly used to refer to IV therapy. Therapies administered intravenously are often called specialty pharmaceuticals.

Compared with other routes of administration, the intravenous route is the fastest way to deliver fluids and medications throughout the body.

Table of Contents

Purposes of Intravenous (IV) Therapy

  • To supply fluid when clients are unable to take in an adequate volume of fluids by mouth
  • To provide salts and other electrolytes needed to maintain electrolyte imbalance
  • To provide glucose (dextrose), the main fuel for metabolism
  • To provide water-soluble vitamins and medications
  • To establish a lifeline for rapidly needed medications.

Intravenous Fluids

SEE ALSO: IV Fluids and Solution Cheat Sheet

There are two types of fluids that are used for intravenous drips; crystalloids and colloids.

Crystalloids are aqueous solutions of mineral salts or other water-soluble molecules. The most commonly used crystalloid fluid is normal saline, a solution of sodium chloride at 0.9% concentration, which is close to the concentration in the blood (isotonic). Ringer’s lactate or Ringer’s acetate is another isotonic solution often used for large-volume fluid replacement. A solution of 5% dextrose in water, sometimes called D5W, is often used instead if the patient is at risk for having low blood sugar or high sodium.

The choice of fluids may also depend on the chemical properties of the medications being given. Intravenous fluids must always be sterile. Crystalloids are commonly used for rehydration, and electrolyte replacement.

Colloids contain larger insoluble molecules, such as gelatin; blood itself is a colloid. Colloids preserve a high colloid osmotic pressure in the blood, while, on the other hand, this parameter is decreased by crystalloids due to hemodilution. Another difference is that crystalloids generally are much cheaper than colloids. Colloids have large particles in them so they are not as easily absorbed into the vascular bed. Because of this property colloids are used to replace lost blood, maintain healthy blood pressure, and volume expansion.

Pre-Catheterization or Preparation

1. Review Physician’s Order

A physician’s order is necessary to initiate IV therapy. The physician’s order should include:

  • Type of solution to be infused
  • Route of administration
  • Exact amount (dose) of any medications to be added to a compatible solution either hourly or 24-hour volume
  • Rate of infusion
  • Duration of infusion or the time over which the infusion is to be completed
  • Physician’s signature

2. Observe Hand Hygiene Procedures

Indications for handwashing and hand antisepsis

  • Wash hands with either a non antimicrobial soap and water or an antimicrobial soap and water when hands are visibly dirty or contaminated with blood or other body fluids.
  • If hands are not visibly soiled, use an alcohol-based hand rub to avoid routinely contaminating hands in all other clinical situations.
  • Decontaminate hands before having direct contact with patients
  • Do not wear artificial fingernails or extenders when having direct contact with patients at high risk

3. Gather Equipment

Prepare and gather the equipment needed for starting the IV.

Always check for the fluid’s expiration date.

  • Inspect solution container for integrity.
    • Glass containers. Hold up to light to look for cracks, clarity, particulate contamination, and expiration date.
    • Plastic containers. Squeeze to check for pinholes, clarity, particulate contamination, and expiration date.
  • Inspect administration set
  • Choose the appropriate set: vented or nonvented
  • Gather venipuncture and dressing supplies
  • Catheter (22 g, 20 g, or 28 g most common)
  • Dressing (gauze or TSM)
  • Tape: 1-inch paper
  • Prepping solution
  • Gloves 2×2 gauze

4. Patient Assessment and Psychological Preparation

It’s important to also prepare the patient on the procedure.

  • Introduce self and verify the client’s identity.
  • Provide privacy
  • Explain the procedure to the client. A venipuncture can cause discomfort for a few seconds, but there should be no discomforts while the solution is flowing.
  • Evaluate the patient preparedness for IV procedure by talking with patient before assessing veins
Patient Information to Consider
  • Patient’s medical diagnosis.
  • History of chronic disease that places patient at risk for complications.
  • History of vasovagal reactions during venipuncture or when blood is seen.
  • Has the patient had vascular access devices?
  • Will the patient be going home with the catheter?
  • If cultural barrier exists, take more time; speak slowly and distinctly but not louder. Use pictures. Keep messages simple, and use interpreter to improve communication.
  • Assess both arms and hand prior to choosing appropriate vein.
  • Choose the lowest best site for size catheter being inserted and type of therapy the patient will receive.
  • Assess for any allergies (e.g., to tape or povidone-iodine)
  • Vital signs for baseline data
  • Skin turgor
  • Allergy to latex, tape or iodine
  • Bleeding tendencies
  • Disease or injury to extremities
  • Status of veins to determine appropriate venipuncture site

5. Site Selection and Vein Dilation

There are several factors you need to consider before initiating venipunctures:

  • Type of solution to be infused. Hypertonic solutions and medications are irritating to vein.
  • Condition of vein. Use soft, straight, bouncy vein; if you run your finger down the vein and it feels like a cat’s tail — avoid! Avoid veins near previously infected areas.
  • Duration of therapy. Choose a vein that can support IV therapy for 72–96 hours.
  • Catheter size. Hemodilution is important.The gauge of the catheter should be as small as possible.
  • Patient age. Elderly and children need additional time for assessment and management of insertion.
  • Patient activity. Ambulatory patients using crutches or walker need catheter placement above the wrist.
  • Presence of disease or previous surgeryPatients with vascular disease or dehydration may have limited venous access. If a patient has a condition causing poor vascular return (mastectomy, stroke), the affected side must be avoided.
  • Presence of shunts or graft. Do not use the arm or hand that has a patent graft or shunt for dialysis.
  • Patient receiving anticoagulation therapy. Patients receiving anticoagulant therapy have a propensity to bleed. Local ecchymoses and major hemorrhagic complications can be avoided if the nurse is aware of the anticoagulant therapy.
    Precautions: Minimal tourniquet pressure; use the smallest catheter that is appropriate for therapy; use care in removing dressing.
  • Patient with allergies. Question regarding allergies to medications, foods, animals, and environmental substances. Identify the allergens:
  • Iodine. Avoid povidone-iodine as skin preparation
  • Latex. Set up latex allergy cart
Vein dilation techniques

Use the techniques below to dilate the vein:

  • Tourniquet. Latex or nonlatex used most frequently. Placed 6–8 inches above the venipuncture site. If BP high, move farther from venipuncture site. If BP low, move as close as possible without risking site contamination.
  • Gravity. Position the extremity lower than the heart.
  • Fist clenching. Instruct patient to open and close his/her fist.
  • Tapping vein. Using thumb and second finger, flick the vein; this releases histamines beneath the skin and causes dilation. Do not slap the vein.
  • Warm compresses. 10 minutes maximum. Do not use microwave!
  • Blood pressure cuff. Inflate to 30 mmHg; great for fragile veins.
  • Multiple tourniquet technique. Use 2 to 3 latex tourniquets; apply one high on arm and leave for 2 minutes; apply second at mid arm below antecubital fossa; collateral veins should appear; apply third if needed.

Tips for selecting veins

  • Suitable vein should feel relatively smooth and pliable, with valves well spaced.
  • Start with distal veins and work proximally.
  • Veins that feel bumpy (like running your finger over a cat’s tail) are usually thrombosed or extremely valvular. Veins will be difficult to stabilize in a patient who has recently lost weight.
  • Sclerotic veins are common among narcotic addicts.
  • Dialysis patients usually know which veins are good for venipunctures.

Catheterization or Catheter Insertion

1. Needle Selection

The smaller the gauge number, the thicker the catheter.

Catheters vary in sizes called gauges. The smaller the gauge number, the thicker the catheter and the more rapidly medicine can be administered and blood can be drawn. Furthermore, thicker catheters cause more painful insertion, so it’s very necessary not to use a catheter that’s larger than you need. The tip of the catheter should be inspected for integrity prior to venipuncture. Only two attempts at venipuncture is recommended.

Recommended gauges

SizeColorRecommended use
14GOrangeIn massive trauma situations.
16GGrayTrauma, surgeries, or multiple large-volume infusions
18GGreenBlood transfusion, or large volume infusions.
20GPinkMulti-purpose IV; for medications, hydration, and routine therapies.
22GBlueMost chemo infusions; patients with small veins; elderly or pediatric patients
24GYellowVery fragile veins; elderly or pediatric patients

2. Don your gloves

Wearing gloves is NOT optional!

The possibility of contact with a patient’s blood while starting an IV is high especially with inexperienced healthcare worker. Gloves must always be present and be worn during catheterization. Moreover, if the risk of blood splatter is high, such as an agitated patient, the nurse should consider face and eye protection as well as a gown.

It’s important to observe proper hand hygiene procedures before putting on sterile gloves. If at any point your gloves’ sterility becomes compromised, take them off and put on a new pair — it’s better to be safe than sorry.

3. Site Preparation

Once you’ve don your gloves, you’ll be now preparing the site of insertion.

  • Apply antimicrobial solution, working from center outward in a circular motion for 2-3 inches for 20 seconds. Use enough friction.
  • Do not shave site. Shaving can cause micro abrasions; remove hair with scissors or clippers only.
  • Depilatories not recommended. Potential for allergic reaction.
  • Do not apply 70% isopropyl alcohol after povidone-iodine preparation. Alcohol negates the effect of povidone-iodine.
  • Cleanse insertion site with one of the following solutions:
  • 2% Chlorhexidine gluconate (preferred)
  • Iodophor (povidone-iodine)
  • 70% Isopropyl alcohol
  • Tincture of iodine 2%

4. Insertion of Catheter into Vein

1. Place the extremity in a dependent position (lower than the client’s heart). Gravity slows venous return and distends the veins. Distending the veins makes it easier to insert the needle properly.

2. Apply a tourniquet firmly 15 to 2 cm above the venipuncture site. Explain that it will feel tight. Tourniquet must be tight enough to occlude venous flow but not so tight that it occludes arterial flow. Obstructing arterial flow inhibits venous filling. If a radial pulse can be palpated, the arterial flow is not obstructed.

  • Massage or stroke the vein distal to the site and in the direction of venous flow toward the heart. This action helps fill the vein.
  • Encourage the client to and unclench the fist. Contracting muscles compresses the distal veins, forcing blood along the veins and distending them.
  • Light tap the vein with your fingertips. Tapping may distend the vein.
  • If the preceding steps fail to distend the vein so that it is palpable, remove the tourniquet and wrap the extremity in a warm, moist towel for 10 to 15 minutes. Heart dilates superficial blood vessels, causing them to fill. Then repeat step 1.

3. Put on clean gloves and clean the venipuncture site. Gloves protect the nurse from contamination by the client’s blood.

  • Clean the site with topical antiseptic swab. Some may use anti-infective solution such as povidone-iodine. Check for allergies.
  • Use a circular motion, moving from the center outward for several inches. This motion carries microorganisms away from the site entry.
  • Permit solution to dry on the skin. Povidone-iodine should be in contact with the skin for 1 minute to be effective.

Insert the catheter and initiate infusion.

4. Use the nondominant hand to pull the skin taut below the entry site.
This stabilizes the vein and makes the skin taut for needle entry. It can also make initial tissue penetration less painful.

5. Hold the over-the-needle catheter at a 15-to 30-degree angle with bevel up, insert the catheter through the skin and into the vein.
Sudden lack of resistance is felt as the needle enters the vein. Jabbing, stabbing or quick thrusting should be avoided because it may cause rupture of delicate veins.

6. Advance the needle catheter approximately 1 cm.
Once blood appears in the lumen or you feel the lack of resistance, lower the angle of the catheter until it almost parallel with the skin and advance the needle catheter approximately 1 cm.

7. Holding the needle portion steady, advance the catheter until the hub is at the venipuncture site.
The catheter is advanced to ensure that it, and not just the metal needle, is in the vein.

8. Release the tourniquet.

9. Apply pressure.
Put pressure on the vein proximal to the catheter to eliminate or reduce blood oozing out of the catheter. Stabilize the hub with thumb and index finger of the nondominant hand.

10. Remove the protective cap from the distal end of the tubing.
Hold it ready to attach to the catheter, maintaining the sterility to the end.

11. Remove the needle.
Carefully remove the needle, engage the needle safety device, and attach the end of the infusion tubing to the catheter hub.

12. Initiate the infusion.

13. Tape the catheter. Tape the catheter by the “U” method or according to the manufacturer’s instructions. Using three strips of tape (about 3 inches long).

14. Dress and label the venipuncture site and tubing according to agency policy. Label should have date on which administration set must be changed. The venipuncture site should also be labeled with the date and time, and type and length of catheter.

15. Document the relevant data, including assessments.

5. Catheter Stabilization and Dressing Management

Catheter should be stabilized in a manner that does not interfere with visualization so you can inspect and do your assessment later. Follow the steps below on how you can achieve this:

  • Tape the catheter by the U, H, or the Chevron method or according to the manufacturer’s instructions. Using three strips of tape (about 3 inches long).
  • Loop the tubing and secure it with tape. Looping and securing the tubing prevent the weight of the tubing or any movement from pulling on the needle or catheter.
  • Dress the venipuncture site and tubing according to agency policy.

Types of dressings acceptable for peripheral catheter

  • Gauze dressing with tape
  • Transparent semipermeable dressing (TSM)

Standards of practice

  • Gauze dressings should be changed every 48 hours on peripheral sites
  • The use of non occlusive-type adhesive bandage strip in place of dressing not recommended
  • TSM dressing can be changed when catheter is changed


1. Labeling

Insertion site

The venipuncture site should be labeled:

  • Date and time
  • Type and length of catheter
  • Nurse’s initials

Administration set

  • Label according to agency policy: label should have date on which administration set must be changed

Solution container

  • Place a time strip on all parenteral solutions
  • Any additives must have a clear label applied to bag

2. Equipment Disposal

  • Needles and stylets shall be disposed of in non permeable, tamper-proof containers.
  • Dispose of all paper and plastic equipment in a biohazard container.

3. Patient Education

Patient must receive information on all aspects of their care. After catheter is stabilized, dressing is applied, and labeling complete:

  • Inform regarding any limitations of movement or mobility
  • Explain all alarms if EID is used
  • Instruct to call for assistance if venipuncture site becomes tender or sore or if redness or swelling develops
  • Advise that site will be checked every shift by the nurse

4. Rate Calculation

  • Ensure appropriate infusion flow.
  • Do not leave patient care environment until rate is calculated and adjusted accordingly.

5. Documentation

Document the relevant data, including assessments.

  • Record the start of the infusion on the client’s chart.
  • Include the date and time of the venipuncture
  • The gauge and length of the device
  • Specific name and location of the accessed vein
  • Amount of solution used, including any additives
  • Container number
  • Flow rate
  • Type, length and gauge of the needle or catheter
  • Venipuncture site, how many attempts were made and location of each attempt
  • The type of dressing applied
  • The client’s general response
  • Your signature
Gil Wayne ignites the minds of future nurses through his work as a part-time nurse instructor, writer, and contributor for Nurseslabs, striving to inspire the next generation to reach their full potential and elevate the nursing profession.

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