- Weight (not increased).
- Skin turgor (normal).
- IV site (should not be red, swollen, hot or hard).
- IV patency (should be flowing as per the set drip rate).
Potassium
Potassium is an electrolyte cation that is more prevalent inside cells than it is
in extracellular fluid. It is used to transmit and conduct neurological impulses
and to maintain cardiac rhythms. Potassium is also used to contract skeletal and
smooth muscles.
In order for a muscle to contract, the concentration of potassium inside the
cell moves out and is replaced by sodium, which is the prevalent electrolyte out-
side the cell (see Sodium). These electrolytes reverse position when the muscle
repolarizes. The concentration of potassium and sodium is maintained by the
sodium-potassium pump found in cell membranes. The sodium-potassium pump
uses adenosine triphosphate (ATP) to pump potassium back into the cell and
sodium out of the cell.
Potassium regulates intracellular osmolality and promotes cell growth. It
moves into cells as new tissues form and leaves cells when tissues break down.
Patients receive potassium from their diet and excrete potassium in urine (90%)
and feces (8%).
Serum potassium is measured to determine if the patient has a normal range
of potassium. The normal serum potassium is between 3.5 to 5.3 milliequiva-
lents per liter (mEq/L). Caution: Serum potassium less than 2.5 mEq/L or greater
than 7.0 mEq/L can cause the patient to have a cardiac arrest. Diseases such as
kidney disease can cause potassium to become imbalanced. When this happens,
the patient will exhibit specific signs and symptoms and the serum potassium
will be outside the normal range.Hyperkalemia
Hyperkalemia occurs when a patient has a serum potassium level greater than
5.3 mEq/L. A number of factors can cause this condition including:- Impaired renal excretion (most common).
- Massive intake of potassium.
- Medications such as potassium-sparing diuretics Aldactone and Dyrenium,
angiotensin-converting enzyme (ACE) inhibitors Vasotec and Prinivil,
which reduce the kidney’s ability to secrete potassium.
(^164) CHAPTER 10 Fluid and Electrolyte Therapy