Caring for Clients With Fluid, Electrolyte, and Acid–Base Imbalances

Vocabulary practice flashcards covering fluid, electrolyte, and acid-base imbalances, regulation mechanisms, and laboratory values based on Chapter 16 of Introductory Medical-Surgical Nursing.

Electrolytes

Substances that carry an electrical charge when dissolved in fluid.

Acids

Substances that release hydrogen into fluid.

Bases

Substances that bind with hydrogen.

Intracellular fluid

Fluid located within the cells, accounting for approximately $60\%$ of total body water.

Extracellular fluid

Fluid outside of the cells, which includes interstitial fluid and intravascular fluid (plasma).

Ten Percent ($10\%$) Body Fluid Loss

A level of fluid loss in adults that is serious and causes the Systolic Blood Pressure (SBP) to drop below $90\,mmHg$.

Twenty Percent ($20\%$) Body Fluid Loss

A level of body fluid loss in the adult that is considered fatal.

ADH (Antidiuretic Hormone)

A water-conserving hormone manufactured by the hypothalamus and stored in the pituitary gland that controls the retention or excretion of water by the kidneys.

Aldosterone

A mineralcorticoid secreted by the adrenal cortex that causes sodium and water retention and potassium loss.

PTH (Parathyroid Hormone)

A hormone that regulates calcium and phosphate balance by influencing bone resorption and calcium absorption/reabsorption.

Insensible losses

Fluid loss through sweat and exhaled air that is not easily measured.

Osmosis

The movement of water through a semipermeable membrane toward a higher concentration until equilibrium is reached.

Filtration

The relocation of water and chemicals from an area of higher pressure to an area of lower pressure according to pressure differences.

Facilitated diffusion

The distribution of substances, such as insulin helping glucose, into cells using carrier cells.

Active transport

The movement of substances from low concentration to higher concentration requiring $ATP$, such as the sodium–potassium pump.

Osmoreceptors

Neurons in the hypothalamus that sense blood concentration and stimulate the release of ADH and trigger the thirst center.

Renin–angiotensin–aldosterone system (RAAS)

A chemical chain reaction involving renin, Angiotensin I, and Angiotensin II to cause vasoconstriction and stimulate aldosterone to increase BP and blood volume.

Natriuretic peptides (ANP and BNP)

Vasodilators released by the heart and brain that reduce blood volume by inhibiting renin and ADH, causing diuresis.

Urine specific gravity

A lab measurement of the kidneys' ability to excrete or conserve $H_2O$ with a normal range of $1.010 - 1.030$.

Creatinine

The end product of muscle metabolism and a reliable indicator of renal impairment ($0.7 - 1.5\,mg/dl$).

Hypovolemia

A low volume of extracellular fluid, also known as fluid volume deficit.

Hemoconcentration

A high ratio of blood components in relation to plasma, often manifested as an elevated Hematocrit ($Hct$).

Hypervolemia

A high volume of water in the intravascular fluid compartment, often leading to weight gain, elevated BP, and edema.

Hemodilution

A reduced ratio of blood components to plasma, manifested as low $Hct$ and low specific gravity.

Third-spacing

The translocation of fluid from the intravascular space to tissue compartments, often caused by hypoalbuminemia or burns.

Hyponatremia

A serum sodium level less than $135\,mEq/L$, often resulting in mental confusion and muscular weakness.

Hypernatremia

A serum sodium level above $145\,mEq/L$, causing thirst, dry mucous membranes, and decreased urine output.

Hypokalemia

A serum potassium level less than $3.5\,mEq/L$, which may cause cardiac dysrhythmias and the presence of U waves on an EKG.

Hyperkalemia

A serum potassium level above $5.5\,mEq/L$, which is very serious and can cause cardiac arrest; EKG may show peaked T waves.

Hypocalcemia

A serum calcium level less than $8.8\,mg/dL$, characterized by a positive Chvostek’s sign, Trousseau’s sign, and tetany.

Hypercalcemia

A serum calcium level greater than $10\,mg/dL$, often caused by parathyroid tumors or prolonged immobilization.

Hypomagnesemia

A serum magnesium level less than $1.3\,mEq/L$, which can cause neuromuscular irritability and laryngeal stridor.

Hypermagnesemia

A serum magnesium level greater than $2.1\,mEq/L$, acting as a muscle relaxant that can cause bradycardia and coma.

Calcium gluconate

The pharmacological antidote for Magnesium ($Mg+$) toxicity.

Metabolic Acidosis

An acid-base imbalance ($pH < 7.35$) caused by shock, renal failure, or diabetic ketoacidosis, often presenting with Kussmaul’s breathing.

Metabolic Alkalosis

An acid-base imbalance ($pH > 7.45$) caused by excessive bicarbonate intake, vomiting, or gastric suctioning.

Respiratory Acidosis

An acid-base imbalance ($pH < 7.35$) resulting from hypoventilation due to causes like drug overdose, pneumonia, or head injuries.

Respiratory Alkalosis

An acid-base imbalance ($pH > 7.45$) resulting from hyperventilation due to anxiety, fever, or overactive thyroid.