6 Foundations of IV and Parenteral Therapy
Learn how to match parenteral therapies with appropriate fluids, vascular access, infusion equipment, and medication-safety practices.
Purpose and routes of
delivers medication or solution without using the gastrointestinal tract. Common injection routes include intradermal, subcutaneous, and intramuscular; intravenous therapy delivers fluid or medication directly into a vein. IV delivery has rapid, predictable systemic effects, but an error can cause harm quickly and leave little time to correct it.
IV therapy may provide hydration, electrolytes, medications, blood components, or nutrition. It requires an authorized order and ongoing assessment of whether the treatment remains appropriate. Match the prescribed route and treatment plan to the patient’s condition, and follow applicable training and facility policy.
Takeaway: Direct access to the circulation makes IV therapy useful, but it also makes careful verification and continued assessment essential.
Fluids and fluid movement
IV solutions can be grouped by their effective concentration relative to plasma and their general effects on water movement. These categories help explain expected fluid shifts, but they do not replace clinical assessment; a solution’s effects can change after infusion or metabolism.
have an effective concentration near that of plasma and generally expand extracellular fluid. Examples include sodium chloride and lactated Ringer’s. Monitor for fluid overload, especially with cardiac or renal impairment.
have a lower effective concentration than plasma and promote water movement into cells. For example, sodium chloride may worsen intravascular depletion, so monitor fluid status and relevant laboratory results.
have a higher effective concentration than plasma and draw water toward the extracellular space. Examples include sodium chloride and dextrose-containing saline combinations. These solutions can cause rapid fluid and electrolyte shifts and require close monitoring and the prescribed access and monitoring plan.
Crystalloids contain small dissolved particles. Colloids contain larger molecules that exert oncotic effects. Blood components and parenteral nutrition are specialized therapies with their own compatibility, equipment, and monitoring requirements.
Choose the solution and rate according to the treatment goal and the person’s condition. Assess the patient, not just the bag: monitor intake and output, vital signs, edema, respiratory status, relevant laboratory results, and response. New shortness of breath, worsening edema, unexpected pain, or a sudden change in condition warrants prompt assessment and escalation according to local protocol.
Takeaway: Solution categories predict general fluid movement, while patient assessment guides safe selection and monitoring.
Vascular access and site safety
Vascular access choices depend on the prescribed therapy, expected duration, vein condition, and risks. The device’s tip location and intended use determine which therapies it can safely deliver.
A short peripheral IV catheter sits in a peripheral vein and is commonly used for short-term fluids and medications suitable for that vein. Inspect the site and remove the catheter when it is no longer needed or complications occur.
A midline catheter is a longer peripheral catheter whose tip does not terminate in a central vein. It can support some therapies longer than a short peripheral IV, but it is not interchangeable with central access. Confirm that the infusion is appropriate for a midline.
A PICC is inserted through a peripheral vein, with its tip terminating in a central vein. Placement and tip position must be verified according to policy.
Other central venous catheters (CVCs) enter a central vein through a neck, chest, or groin site. They enable central access but carry insertion- and maintenance-related risks, including bloodstream infection and thrombosis.
An implanted port is a central access device beneath the skin. Trained personnel access it with an appropriate noncoring needle.
Intraosseous access provides emergency access through bone marrow when rapid vascular access is needed and IV access is not readily available; it is generally temporary.
Use hand hygiene and aseptic technique with every device, keep connections secure, and inspect the site and dressing. Assess for , , , infection, and malfunction. Pain, swelling, coolness, redness, leakage, warmth, or a palpable venous cord requires prompt assessment and action under local protocol. Do not assume a line is safe to use simply because fluid can be infused.
Takeaway: Select access for the therapy and monitor it for complications; a device’s appearance or ability to infuse does not establish that it is safe.
Infusion equipment and flow rates
A typical IV setup includes a solution container, administration tubing, a flow-control device, and connectors attached to vascular access. Primary tubing delivers a continuous solution. A secondary, or piggyback, set delivers an intermittent medication through compatible primary tubing. Use equipment compatible with the device and therapy, and label lines as required by policy.
Gravity tubing uses a roller clamp and drip chamber to regulate flow. Flow can vary with bag height, patient movement, and other factors, so observe it closely.
Volumetric infusion pumps control a programmed volume or rate. Syringe pumps are commonly used when small volumes or precise, low flow rates are needed.
may include a medication library and dose limits. They do not replace verification of the order, concentration, programming, or patient response.
A basic gravity-rate calculation is:
For example, over using tubing calibrated at gives:
This illustrates the calculation only. Use the prescribed rate and the actual tubing’s drop factor. Use a pump when ordered or required by policy, particularly when precise delivery is important.
Before starting or changing an infusion, trace tubing from container to patient, confirm the correct channel and line, check the programmed rate and volume, and ensure the tubing is not kinked or disconnected. When an alarm occurs, assess the patient and the full infusion system rather than silencing it without identifying the cause. Follow manufacturer instructions and facility policy; remove damaged or unreliable equipment from use and report it.
Safe IV medication administration
Because IV medication enters the circulation directly, verify each step before administration and continue monitoring afterward.
Verify the order and patient. Apply the organization’s medication-administration checks, including correct patient, medication, dose, route, time, and documentation. Check allergies, indication, relevant clinical data, and any required independent verification for high-alert medications.
Check the medication and method. Confirm concentration, expiration, preparation, prescribed dilution, administration rate, and whether the medication is appropriate for the access device. Consult an authoritative drug reference or pharmacist when information is unclear.
Check compatibility. Verify compatibility with the solution, tubing, connectors, and any medication already infusing. Do not assume two medications can share a line. Use a separate lumen or an approved pause-and-flush procedure when indicated; the correct approach depends on the drugs and device.
Protect asepsis. Perform hand hygiene, disinfect the access point with an approved antiseptic and allow it to dry as directed, and use sterile, single-use equipment. Use single-dose containers for one patient only; never use an IV bag or administration set as a source for multiple patients.
Deliver at the prescribed rate. Use the correct delivery method and a pump when specified or required. Do not speed up an infusion to compensate for a delay. For IV push medications, follow drug-specific instructions and organizational policy; there is no universal safe push rate.
Monitor and document. Observe the patient and access site during and after administration as appropriate to the medication. Document the medication, dose, route, time, relevant site or line assessment, and response according to policy.
If a reaction, suspected , pump malfunction, or other serious problem occurs, stop or pause the infusion when indicated by protocol, assess the patient, and promptly obtain appropriate clinical help. Follow medication-specific and facility procedures. Do not flush a suspected unless the applicable protocol directs it.
Takeaway: Reliable IV medication delivery combines order verification, compatibility checks, aseptic access, prescribed rate, and ongoing observation.