By the end of the class, the student will be able to: 1. Calculate the rate of administration for intravenous (IV) fluids using infusion pumps. 2. Calculate the rate of administration for IV fluids using gravity and a drop factor. 3. Calculate doses and administration time for medication given IV push. 4. Formulate nursing care for a patient receiving IV therapy
Overview
This lecture covers IV therapy concepts, types of IV fluids, and step-by-step methods for calculating IV flow rates, drops per minute, and IV push doses, focusing on safe and accurate administration.
IV Fluid Concepts
- Osmolality measures solute concentration per kilogram/liter of fluid, affecting water movement between compartments.
- Tonicity refers to the relative concentration of IV fluids; determines fluid movement in/out of cells.
- Osmosis is water movement from areas of low osmolality to high osmolality.
- Isotonic solutions cause no fluid shift; hypertonic solutions pull fluid into plasma; hypotonic solutions move fluid into tissues/cells.
Types of IV Fluids
- Crystalloids contain small electrolytes that pass through membranes; come as isotonic, hypertonic, or hypotonic.
- Colloids have large molecules that stay in plasma and expand blood volume (e.g., dextran 40).
- Isotonic fluids expand plasma volume without a shift; used for hydration and plasma expansion.
- Hypertonic fluids pull fluid from tissues to plasma (treat edema).
- Hypotonic fluids move water into cells/tissues; treat hypernatremia or cellular dehydration.
IV Fluid Administration & Safety
- Replacement fluids restore measured losses; maintenance fluids maintain levels via continuous infusion.
- Primary IV lines deliver main fluids; secondary lines (IV piggyback) deliver intermittent medications—compatibility is crucial.
- Monitor IV sites and flow every 30–60 minutes for infiltration, flow, and device power.
- Signs of fluid overload: tachycardia, peripheral edema, distended neck veins, dyspnea, cough, hypertension.
IV Flow Rate Calculations
- IV rates are usually calculated in mL/hour or drops/minute.
- Drop factor = number of drops/mL (found on tubing; crucial for gravity infusions).
- Use dimensional analysis, ratio/proportion, or “desired over have” methods to solve calculation problems.
- Factor converter: 60/drop factor (use to convert between drops/minute and mL/hour).
- Round calculated pump settings to whole numbers.
IV Push & Drug Calculations
- IV push dosing uses “desired dose over have” formula for safe medication administration.
- Always double-check compatibility and calculations before administering drugs.
Key Terms & Definitions
- Osmolality — concentration of solutes per kilogram/liter of fluid.
- Tonicity — relative concentration of IV solution, affecting cell fluid movement.
- Crystalloids — IV fluids with small solutes capable of moving through membranes.
- Colloids — IV fluids with large molecules that remain in vascular space.
- Drop factor — number of drops to equal 1 mL, specific to IV tubing.
Action Items / Next Steps
- Complete all IV calculation practice problems in your textbook.
- Attend or seek out math/tutoring sessions if needed.
- Participate in the mandatory quiz and discussion board.
- Practice additional problems for confidence and skill.