Fluid and Electrolyte Lecture Notes

A set of vocabulary terms covering hypernatremia, hyponatremia, fluid management protocols, and the effects of diuretics on electrolytes.

Hypernatremia

A high sodium concentration in the ECF where cells have water leave by osmosis and shrink, often resulting in signs of cerebral dysfunction.

Hyponatremia

A low sodium concentration in the ECF where water moves into cells by osmosis causing them to swell, which may lead to cerebral dysfunction.

Sodium ($Na^+$) Range

The normal concentration range for sodium is $135-145\,mEq/L$.

Renal Failure Signal

An output below $30\,mc/hour$ may indicate renal failure, and the patient should be assessed to ensure they void $Q85$.

I and O Measurement

To maintain balance, fluid output should be equal to or within $300-500\,mL$ of intake.

Antiemetic

A medication ordered PRN for the treatment of nausea and vomiting.

Antidiarrheal

A medication used for loose stool to help prevent further electrolyte loss.

At-risk Populations

Infants, children, and older adults are at higher risk for sodium imbalances due to changes in fluid needs and body composition.

Signs of Fluid Overload

Symptoms include increased respirations, JVD, elevated blood volume, bounding pulse, lung crackles or wheezes, weight gain, edema, and pink frothy sputum.

Lasix (Furosemide)

A loop diuretic that can cause a loss of $Na^+$, $K^+$, $Ca^+$, and $mg$, often leading to hypokalemia.

Thiazide Diuretics

A class of diuretics that may cause hypokalemia, potentially requiring $K^+$ supplements prescribed by a HCP.

Sodium ($Na^+$) Function

The primary electrolyte that controls ECF volume and fluid distribution in the body.

Hypokalemia

A condition characterized by low serum $K^+$ levels, which can be caused by loop diuretics like Furosemide.

Physical Signs of Sodium Imbalances

Include flushed, pale, hot, or dry skin; decreased turgor; thirst or nausea; dry/cracked lips or tongue; and increased heart rate or body temperature.