6.3 IV Therapy & Parenteral Administration

Intravenous Fluids and Tonicity

Intravenous (IV) therapy restores fluid and electrolytes, delivers medication, and provides blood products. Understanding tonicity — how a solution shifts water across cell membranes relative to plasma — is essential and frequently tested.

A memory anchor: iso = stays (fills the vessel), hypo = into the cell (cells swell), hyper = out of the cell (cells shrink). Always assess for fluid overload (crackles, dyspnea, bounding pulse, distended neck veins, sudden weight gain) when infusing volume, especially in older adults and clients with heart or renal failure.

Starting and Monitoring a Peripheral IV

When initiating a peripheral IV, apply a tourniquet, clean the site (chlorhexidine), insert at a 10-30 degree angle bevel-up, advance the catheter, release the tourniquet, and secure with a transparent dressing labelled with date and time. Choose distal veins first and avoid areas of flexion. Verify patency by a free flow and absence of swelling.

Ongoing monitoring checks the site, the rate, and the client. Compare infiltration versus phlebitis, a classic distractor pair:

• Infiltration — the catheter has slipped out of the vein and fluid enters surrounding tissue. Signs: cool, pale, swollen skin around the site, tenderness, and slowed or stopped flow. Action: stop the infusion, remove the catheter, elevate the limb, apply warm or cool compress per policy, and restart at a new site.
• Phlebitis — inflammation of the vein wall. Signs: warmth, redness, tenderness, and a red streak or palpable cord along the vein. Action: discontinue and restart elsewhere; warm compress; monitor for infection.
• Infection — redness, purulent drainage, fever; use strict aseptic technique and remove promptly.
• Air embolism and fluid overload are additional risks; keep systems closed and use pumps for high-risk infusions.

IV potassium chloride is a high-alert must-know: always dilute it and infuse slowly via a controlled infusion device — never as an IV push, because rapid administration can cause fatal cardiac dysrhythmias.

Blood Product Basics

Before a transfusion, confirm the order, obtain consent, verify the product and client identity with a two-nurse check of ABO/Rh type and unit number, and prime tubing with normal saline only (never dextrose or LR, which cause hemolysis or clotting). Take a baseline set of vital signs, begin slowly, and stay with the client for the first 15 minutes, when most severe reactions appear.

At the first sign of a reaction — fever, chills, low back pain, dark urine, dyspnea, or hypotension (suggesting an acute hemolytic/ABO-incompatibility reaction) — stop the transfusion immediately, keep the IV line open with normal saline via new tubing, notify the prescriber and blood bank, and monitor closely. Stopping the offending blood while maintaining venous access is always the priority action.

Injection Routes and Central-Line Awareness

Match route to purpose:

• Subcutaneous (SubQ) — small volumes (up to ~1 mL) into fatty tissue at a 45-90 degree angle (heparin, insulin). Rotate sites; do not aspirate or massage heparin injections.
• Intramuscular (IM) — larger volumes at a 90 degree angle; the ventrogluteal site is preferred for adults because it is free of major nerves and large blood vessels, making it safe and reliable.
• Intradermal (ID) — tiny volumes into the dermis at a 5-15 degree angle to form a bleb (TB skin tests, allergy testing).

Central venous access devices (PICCs, tunnelled catheters, ports) deliver irritating drugs, long-term therapy, or large volumes. Scope of practice for accessing and managing central lines varies by province and employer; the entry-level PN must know the awareness essentials — strict aseptic technique, assessing for signs of infection, and never using a line without confirming it is appropriate within their authorized scope and competence.

Worked example: IV flow rate

Gravity (drip) infusions require calculating drops per minute (gtt/min) = (total volume in mL x drop factor in gtt/mL) / total time in minutes. Example: 1000 mL over 8 hours with tubing of 15 gtt/mL. Convert 8 hours to 480 minutes, then (1000 x 15) / 480 = 15,000 / 480 = 31 gtt/min (rounded). For an electronic pump you instead set mL/hour: 1000 mL / 8 h = 125 mL/h. Knowing both forms — and converting time to minutes for drip rates — prevents a common miscalculation.

Recognizing transfusion-reaction types

Beyond acute hemolytic reactions, the PN recognizes: a febrile non-hemolytic reaction (fever and chills without hemolysis — the most common), an allergic/urticarial reaction (hives, itching), and anaphylaxis (wheezing, hypotension, angioedema). For any moderate-to-severe reaction the first action is the same: stop the transfusion and keep the line open with normal saline, then assess and notify. Circulatory overload (TACO) from too-rapid infusion presents with dyspnea and crackles and is managed by slowing/stopping the infusion and elevating the head of bed.