Intravenous Therapy

A. Indications Of Intravenous Therapy:
1. Establish or maintain a fluid or electrolyte balance
2. Administer continuous or intermittent medication
3. Administer intravenous anesthetics
4. Administer fluid to keep vein open (KVO)
5. Administer blood or blood components
6. Administer bolus medication
7. Maintain or correct a patient's nutritional state
8. Administer diagnostic reagents
9. Monitor hemodynamic functions

B. Intravenous Devices :
1. Steel Needles, Example; Butterfly catheter. Mostly used to deliver small quantities of medicines, to deliver fluids via the scalp veins in infants, and sometimes to draw blood samples.

2. Over the Needle Catheters, Example; peripheral IV catheter. This is the kind of catheter you will primarily be using. Catheters (and needles) are sized by their diameter, which is called the gauge. Obviously, the greater the diameter, the more amounts of fluid can be delivered.


C. Intravenous Fluids :
IV fluids are usually an intervention to provide volume replacement, administer medications, including electrolytes, monitor cardiac functions. For example, a patient comes into the ED with gastroenteritis and is dehydrated from vomiting and diarrhea.

There are three main types of fluids:
1. Isotonic fluids, close to the same osmolarity as serum. They stay inside the intravascular compartment, thus expanding it. This fluid can be helpful in hypotensive or hypovolemic patients and alsoc an be harmful. There is a risk of fluid overloading, especially in patients with CHF and hypertension such as Lactated Ringer's (LR), NS (normal saline, or 0.9% saline in water).

2. Hypotonic fluids, it's less osmolarity than serum. This fluid dilutes the serum, which decreases serum osmolarity. Hypotonic fluids is helpful when cells are dehydrated such as a dialysis patient on diuretic therapy, also be used for hyperglycemic conditions like diabetic ketoacidosis, in which high serum glucose levels draw fluid out of the cells and into the vascular and interstitial compartments.

Can be dangerous to use because of the sudden fluid shift from the intravascular space to the cells. This can cause cardiovascular collapse and increased intracranial pressure (ICP) in some patients. Example: .45% NaCl, 2.5% dextrose.

3. Hypertonic fluids, have a higher osmolarity than serum. Pulls fluid and electrolytes from the intracellular and interstitial compartments into the intravascular compartment. Can help stabilize blood pressure, increase urine output, and reduce edema.

Rarely used in the prehospital setting, care must be taken with their use. Dangerous in the setting of cell dehydration. Examples: D5% .45% NaCl, D5% LR, D5% NS, blood products, and albumin.

Flow Rates :
You will often need to calculate IV flow rates. The administration sets come in two basic sizes:
- Microdrip sets, Allow 60 drops (gtts) / mL through a small needle into the drip chamber (Good for medication administration or pediatric fluid delivery).
- Macrodrip sets, Allow 10 to 15 drops / mL into the drip chamber (Great for rapid fluid delivery. Also used for routine fluid delivery).
- Fluid may be ordered at a KVO rate. This means to Keep the Vein Open, or run in fluids very slowly, enough to keep the vein open, but not really deliver much volume.