Intravenous Infusion: Types and Uses

Intravenous (IV) Infusion

Definition

IV infusion is the administration of fluids, medications, or nutrients directly into a vein through a catheter for therapeutic or diagnostic purposes.

Types of IV Infusions

• Continuous Infusion: A steady flow of fluid over time (e.g., normal saline for hydration).
• Intermittent Infusion: Given at intervals, often via an IV push or piggyback (e.g., antibiotics).
• Bolus Injection: A single, large dose administered rapidly (e.g., emergency drugs like epinephrine).
• Patient-Controlled Analgesia (PCA): Allows patients to self-administer controlled doses of pain medication.

IV Fluids Classification:

• Crystalloids: Small molecules that pass easily through membranes (e.g., normal saline, lactated Ringer’s).
• Colloids: Larger molecules that stay in circulation longer, drawing fluid into vessels (e.g., albumin, dextran).
• Blood Products: Includes whole blood, packed RBCs, platelets, and plasma.
• Parenteral Nutrition: Used when oral/enteral feeding is not possible (e.g., total parenteral nutrition, TPN).

Common IV Sites

• Peripheral IV (PIV): Short-term use; placed in veins of the hand, arm, or foot.
• Central Venous Catheter (CVC): Used for long-term therapy; placed in the subclavian, jugular, or femoral vein.
• Peripherally Inserted Central Catheter (PICC): A long-term catheter inserted peripherally but threaded to a central vein.
• Intraosseous (IO) Access: Used in emergencies when IV access is difficult; fluid is infused into the bone marrow.

IV Administration Equipment

• IV Catheter (Cannula): A small tube inserted into a vein.
• Drip Chamber: Prevents air bubbles from entering the bloodstream.
• Roller Clamp: Adjusts the flow rate.
• Infusion Pump: Delivers precise volumes of IV fluid.
• Saline Lock (Heplock): Allows intermittent IV access without continuous infusion.

IV Cannula Color Code & Gauge Size

IV cannulas come in different colors, each representing a specific gauge (G) size. The gauge number determines the internal diameter of the cannula:

• Lower gauge number = Larger diameter (faster fluid flow)
• Higher gauge number = Smaller diameter (slower flow, used for delicate veins)

IV Cannula Color Code Chart

Color	Gauge (G)	Outer Diameter (mm)	Flow Rate (mL/min)	Common Uses
Orange	14G	2.1 mm	270 mL/min	Rapid fluid resuscitation, emergency, trauma
Grey	16G	1.8 mm	200 mL/min	Major surgery, blood transfusion, trauma
Green	18G	1.3 mm	90-100 mL/min	Routine blood transfusion, IV fluids
Pink	20G	1.1 mm	60-80 mL/min	General IV therapy, medications
Blue	22G	0.9 mm	36 mL/min	Elderly patients, children, smaller veins
Yellow	24G	0.7 mm	20 mL/min	Neonates, infants, very fragile veins
Violet	26G	0.6 mm	13 mL/min	Premature babies, very delicate veins

How to Identify Gauge by Color?

• Look at the plastic hub of the IV cannula → It is color-coded according to the gauge size.
• Larger cannulas (lower gauge, e.g., 14G, 16G) → Used in emergency situations for rapid infusion.
• Smaller cannulas (higher gauge, e.g., 22G, 24G) → Used for slow infusion in children, elderly, and fragile veins.

Calculation of IV Flow Rate

IV Infusion Complications

• Infiltration: Fluid leaks into surrounding tissue → swelling, pallor, coolness.
• Phlebitis: Vein inflammation → redness, warmth, pain.
• Extravasation: Leakage of vesicant drugs → tissue damage, necrosis.
• Air Embolism: Air enters the bloodstream → chest pain, dyspnea, hypotension.
• Fluid Overload: Excess IV fluid → hypertension, pulmonary edema.
• Infection: Bacterial contamination → fever, erythema, purulent drainage.

IV Therapy Safety Measures

• Use aseptic technique during insertion.
• Monitor for signs of complications (redness, swelling, pain).
• Adjust flow rates carefully to prevent overload.
• Rotate IV sites every 72-96 hours (for peripheral lines).
• Use filters for specific medications (e.g., TPN, chemotherapy).
• Flush IV lines with saline/heparin to prevent clot formation.

Special Considerations

• Pediatrics: Use microdrip sets and smaller catheters.
• Geriatrics (Medical care of old age patient): Fragile veins; lower flow rates.
• Renal & Cardiac Patients: Risk of fluid overload; careful monitoring required.
• Chemotherapy: Administered via central lines to avoid vein irritation.

IV Fluid Comparison Chart

IV Fluid	Type	Uses	Precautions
Normal Saline (NS)	Isotonic	Dehydration, blood transfusions	Metabolic acidosis, fluid overload
Ringer’s Lactate (RL)	Isotonic	Burns, trauma	Avoid in liver disease
D5W (5% Dextrose)	Hypotonic	Hypoglycemia, energy source	Risk of hyponatremia
DNS (Dextrose Normal Saline)	Hypertonic	Postoperative fluids	Risk of hyperglycemia
D10W, D25W, D50W	Hypertonic	Severe hypoglycemia	Risk of vein irritation
Albumin	Colloid	Burns, liver disease	Expensive, allergy risk
Dextran	Colloid	Shock, blood loss	Can cause clotting issues

IV Fluids: Composition, and Uses

IV fluids are classified into crystalloids and colloids based on their composition and effects on the body's fluid balance. Below is a detailed overview of commonly used IV fluids, including Ringer’s Lactate (RL), Normal Saline (NS), NARROT, Dextrose, and others.

Crystalloids (Most Common Intravenous Fluids)

Crystalloids contain small molecules that can move freely between blood vessels and tissues. They are mainly used for fluid replacement and electrolyte balance.

(A) Normal Saline (NS) – 0.9% Sodium Chloride

Composition:

• Sodium (Na⁺) – 154 mEq/L
• Chloride (Cl⁻) – 154 mEq/L
• Osmolarity – 308 mOsm/L (isotonic)

Uses:

• ✔ Fluid resuscitation in dehydration, vomiting, diarrhea
• ✔ Used with blood transfusions
• ✔ Dilution of medications
• ✔ Hyponatremia (low sodium levels)

Precautions:

• ⚠ Can cause hyperchloremic metabolic acidosis (excess chloride shifts pH balance)
• ⚠ Can lead to fluid overload in patients with kidney or heart disease

(B) Ringer’s Lactate (RL) / Lactated Ringer’s (LR)

Composition:

• Sodium (Na⁺) – 130 mEq/L
• Potassium (K⁺) – 4 mEq/L
• Calcium (Ca²⁺) – 3 mEq/L
• Chloride (Cl⁻) – 109 mEq/L
• Lactate – 28 mEq/L (metabolized in liver to bicarbonate)
• Osmolarity – 273 mOsm/L (isotonic)

Uses:

• ✔ Fluid replacement in burns, trauma, surgery
• ✔ Acidosis correction (due to lactate metabolism)
• ✔ Used in obstetrics (labor and delivery)

Precautions:

• ⚠ Not for patients with liver disease (impaired lactate metabolism)
• ⚠ Not compatible with blood transfusions (calcium can cause clotting)

(C) Dextrose Solutions (Glucose Solutions)

Dextrose solutions provide energy and help maintain blood sugar levels.

1. Dextrose 5% (D5W)

Composition:

• 50g dextrose per liter
• Osmolarity – 252 mOsm/L (initially isotonic, becomes hypotonic after metabolism)

Uses:

• ✔ Treats hypoglycemia
• ✔ Provides calories and energy
• ✔ Used in hypernatremia (high sodium levels)

Precautions:

• ⚠ Can cause hyponatremia if used excessively
• ⚠ Not suitable for diabetic patients

2. Dextrose 10% (D10W), 25%, 50%

• Higher concentrations (D10, D25, D50) are hypertonic
• Used for severe hypoglycemia (low blood sugar levels)
• D50W is given as a bolus in emergency hypoglycemia

(D) Dextrose Saline (DNS)

Combination of dextrose and normal saline.

Common Types:

• Dextrose 5% in Normal Saline (D5NS)
• Dextrose 10% in Normal Saline (D10NS)

Uses:

• ✔ Provides energy and electrolyte balance
• ✔ Used in postoperative fluid management
• ✔ Maintains hydration in fasting patients

Precautions:

• ⚠ Can cause hyperglycemia (high blood sugar) in diabetics

Colloid IV Fluids (For Severe Cases)

Colloids contain large molecules (proteins, starches) that stay in the bloodstream and draw fluid from tissues. Used for shock, burns, and severe hypovolemia.

(A) Albumin (5% or 25%)

• ✔ Used in hypoalbuminemia, burns, liver disease
• ⚠ Expensive, risk of allergic reactions

(B) Dextran (Dextran 40, Dextran 70)

• ✔ Plasma volume expansion in shock, blood loss
• ⚠ Can cause coagulation abnormalities

(C) Hydroxyethyl Starch (HES)

• ✔ Used in hypovolemia, sepsis
• ⚠ Increased risk of kidney injury

IV Infusion Nature Types: 

1. Isotonic Solutions

Definition: These solutions have the same osmolarity as blood plasma (~275-295 mOsm/L).

Effect on Cells: No fluid shift between blood vessels and cells.

Examples:

• 0.9% Normal Saline (NS)
• Lactated Ringer’s (LR)
• 5% Dextrose in Water (D5W) (initially, but acts as hypotonic in the body)

Uses: Used for fluid replacement in dehydration, blood loss, or surgery.

2. Hypertonic Solutions

Definition: Higher osmolarity than blood plasma (>295 mOsm/L).

Effect on Cells: Draws water out of cells into the bloodstream.

Examples:

• 3% or 5% NaCl (Hypertonic Saline)
• 10% Dextrose in Water (D10W)
• D5NS (5% Dextrose in Normal Saline)

Uses: Used for severe hyponatremia, cerebral edema, or rapid fluid expansion.

Caution: Can cause fluid overload; use with care in heart or kidney patients.

3. Colloid Solutions

Definition: Contain large molecules (proteins/starches) that stay in the bloodstream and increase osmotic pressure.

Effect on Cells: Pulls fluid from interstitial and intracellular spaces into blood vessels.

Examples:

• Albumin (5% or 25%)
• Dextran
• Hetastarch (Hespan)
• Fresh Frozen Plasma (FFP)

Uses: Used for severe blood loss, shock, or burns.

Comparison Table

Type	Osmolarity	Effect on Cells	Common Uses
Isotonic	Same as blood (~290 mOsm/L)	No movement of fluid	Dehydration, blood loss, surgery
Hypertonic	Higher than blood (>295 mOsm/L)	Pulls water out of cells	Hyponatremia, cerebral edema
Colloid	Large molecules, increases oncotic pressure	Pulls water into blood vessels	Shock, burns, blood loss

Special Considerations

• Hypovolemic Shock: RL or NS is preferred.
• Hyponatremia (Low blood sodium): NS or hypertonic saline (3% NaCl).
• Hypernatremia (High blood sodium): D5W or RL (to dilute excess sodium).
• Diabetes: Avoid dextrose solutions unless treating hypoglycemia.
• Kidney Disease: Avoid fluids with high potassium (e.g., RL).
• Liver Disease: Avoid RL due to lactate metabolism issues.