Parenteral Administration: Intravenous Route

Introduction to Intravenous (IV) Therapy Principles

• Intravenous (IV) therapy is defined as the injection of a solution into a vein.
• IV administration is considered more effective under the following conditions:
  • When a large volume of fluid must be administered quickly to a patient.
  • When medications must be absorbed by the body at a faster rate than other parenteral routes.
• A specific written order from a physician is required for IV therapy. This order must include:
  • The date the order was written.
  • The exact type of solution or medication to be administered.
  • The prescribed dosage.
  • The rate of administration.
  • The frequency of administration.

Advantages and Disadvantages of the Intravenous Route

• Advantages of IV Therapy:
  • Drugs can be administered directly into the vein through a syringe injection.
  • Drugs can be administered either intermittently or via continuous infusion.
  • Access can be gained through either a peripheral or a central IV line.
  • The route is usually more comfortable for drug administration than the Intramuscular (IM) or subcutaneous routes.
• Disadvantages of IV Therapy:
  • The process requires an extended amount of time to administer compared to other injections.
  • It requires a skilled and trained healthcare provider to perform the administration.
  • The presence of IV lines decreases patient mobility.
  • There is an increased risk of infection.
  • There is a higher possibility of severe adverse drug reactions.

Fluid Compartments of the Body

• There are three primary compartments in the body:
  • Intravascular: This includes blood vessels such as arteries, veins, and capillaries.
  • Intracellular: This refers to the space inside the cells.
  • Interstitial: This refers to the space between the cells.
• The Extracellular compartment includes both the intravascular and interstitial compartments and accounts for $\frac{1}{3}$ of the total body water.
• The Intracellular compartment is the largest, making up $\frac{2}{3}$ of the total body water.

IV Therapy Equipment and Infusion Control

• IV Administration Sets: These sets connect large-volume solution bags to the IV access device in the patient's vein. Components of these sets include spikes, drip chambers, tubing with control clamps, and needle adapters.
• Types of Drip Chambers:
  • Macrodrip: Delivers $10, 15, \text{ or } 20\,\text{drops per mL}$.
  • Microdrip: Delivers $60\,\text{drops per mL}$.
• Infusion-Control Pumps: All administration devices for IV fluids and drugs include safety features such as alarm systems, automatic stop capability, and programmability.
• Specific device types include:
  • Controllers: Use gravity for flow.
  • Pumps: Classified as nonvolumetric and volumetric.
  • Syringe pumps.
• Formula for Calculating Drops per Minute:
  • $\frac{\text{mL of solution}}{\text{Hours of administration}} \times \frac{\text{Drops}}{\text{mL}} \text{ (drip factor)} \times \frac{1\,\text{hr}}{60\,\text{min}} = \text{Drops/min}$

Intravenous Access Devices

• Peripheral Access Devices: Intended for short-term use; typically placed in peripheral veins located in the hand or forearm.
• Midline Catheters: Designed for use over $2\,\text{to } 4\,\text{weeks}$; these are inserted into intermediate-sized veins and advanced into larger vessels.
• Central Access Devices: Inserted into large, intermediate-sized vessels such as the subclavian, jugular, or femoral veins.
  • Tunneled Central Venous Catheters: Surgically placed with the proximal end of the catheter exiting on the chest.
• Implantable Venous Infusion Ports: Surgically placed into central veins for long-term therapy (IV fluids, medications, Total Parenteral Nutrition (TPN), and chemotherapy). These are accessed using a $90\text{-degree}$ Huber needle.

Types of Intravenous Solutions and Concentrations

• Solutions consist of water containing one or more dissolved particles, known as solutes. The concentration of these dissolved particles is called osmolality.
• Solutions are administered to replace body losses of water and electrolytes, including $Na^+$, $Cl^-$, and $K^+$.
• Isotonic Solutions:
  • Maintain a similar osmolality as blood.
  • Primarily used for fluid replacement.
  • Examples include $D5/0.2\%$ and $0.9\%\,\text{sodium chloride}$.
• Hypotonic Solutions:
  • Possess a lower osmolality than blood.
  • Used to treat conditions involving cellular dehydration.
  • Examples include $0.2\%$ and $0.45\%\,\text{sodium chloride}$.
• Hypertonic Solutions:
  • Possess a higher concentration of dissolved particles than blood.
  • These are rarely used because they tend to pull fluids from the extracellular compartment into the blood vessels.
• Total Parenteral Nutrition (TPN) Solutions:
  • Contain all electrolytes needed by the body as well as amino acids, carbohydrates (dextrose), and fatty acids.

Solution Containers

• Large-Volume Solution Containers: These are plastic or glass containers that are vacuum sealed. Glass containers are sealed with a hard rubber stopper and a metal disk, which must be removed prior to use. Volumes range from $100\,\text{to } 2000\,\text{mL}$.
• Small-Volume Solution Containers: Used for intermittent infusion via tandem setup, piggyback, or IV rider. Most intermittent diluted drug infusions are infused over a period of $20\,\text{to } 60\,\text{minutes}$.

Nursing Principles and Responsibilities

• General Principles for Administration:
  • Understand the purpose of the drug.
  • Adhere to the "seven rights" of medication administration.
  • Determine any compatibility issues between drugs or solutions.
  • Use strict aseptic technique.
  • Utilize the SASH method (Saline, Administer drug, Saline, Heparin/Saline flush).
  • Calculate drip rates accurately.
• Specific Nursing Techniques:
  • Administering via saline lock/medlock.
  • Administering IV bolus medications through capped IV lines.
  • Administering through an established IV line or implanted venous access device.
  • Adding medication to an IV bag, bottle, or volume-control device.
  • Utilizing piggyback sets and changing to the next container of solution.
• Maintenance Responsibilities:
  • Care for insertion sites and implanted ports.
  • Perform dressing changes.
  • Flush catheters to maintain patency.
  • Discontinue IV infusions when appropriate.
  • Verify medication orders for correct dose and recommended infusion rate.
  • Monitor the insertion site, equipment usage, and provide patient teaching.

Complications of IV Therapy

• Localized Complications:
  • Phlebitis: Inflammation of the vein.
  • Thrombophlebitis: Inflammation of the vein with a blood clot.
  • Localized Infection.
  • Infiltration: Non-vesicant fluid leaking into tissue.
  • Extravasation: Vesicant/irritant medication leaking into tissue.
• Systemic Complications:
  • Septicemia: Systemic infection in the blood.
  • Air in tubing/Air embolus.
  • Circulatory overload and Pulmonary edema.
  • Pulmonary embolism.
  • Catheter embolism.
  • "Speed shock": A systemic reaction occurring when a substance is injected into the circulatory system too rapidly.

Questions & Discussion

• Question 1: Equipment setup for primary IV with a secondary piggyback infusion.
  • Response: The nurse should hang the secondary bag higher than the primary bag to ensure the secondary medication infuses first via gravity.
• Question 2: Which solution is most hypertonic? Alternatives: $0.9\%\,NaCl$, $0.45\%\,NaCl$, $D5/0.9\%\,NaCl$, $D5/0.2\%\,NaCl$.
  • Response: $D5/0.9\%\,NaCl$ is the most hypertonic among the options provided.
• Question 3: Use of glass bottles for IV administration.
  • Response: The nurse must use a vent added to the tubing to prevent the stoppage of flow, as glass containers do not collapse like plastic bags and require air displacement.
• Question 4: Handling volume discrepancies (noticing 900 mL left in a bag when there should only be 500 mL).
  • Response: The nurse should notify the prescriber of the difference in amounts and obtain new orders. The rate should never be increased to "catch up" as this risk speed shock or circulatory overload.
• Question 5: Syringe size for flushing central venous catheters (CVC).
  • Response: To maintain patency of unused ports, a $10\,\text{mL}$ syringe is recommended to avoid excessive pressure that smaller syringes might generate, which could damage the catheter.