Fluid Imbalances and Regulation - Lecture Notes Review

Flashcards covering key concepts from the lecture notes on fluid imbalances, regulation mechanisms, and related treatments.

Dehydration

Loss of water, often with increased osmolality; causes include vomiting, diarrhea, fever, sweating, and DKA; S/S include thirst, lethargy, dry mucosa; treatment: oral rehydration if possible or IV fluids (D5W for severe cases).

Hypovolemia

Loss of water and electrolytes; causes bleeding, GI loss, burns, trauma, diuretics; S/S thirst, dry mucosa, poor turgor, hypotension, tachycardia, possible hypovolemic shock; treatment: oral fluids, IV NS/LR, blood products if needed.

Hypervolemia

Excess water and sodium in extracellular space; causes heart failure, kidney failure, cirrhosis, meds; S/S JVD, edema, bounding pulse, dyspnea, hypertension; treatment: diuretics, sodium/fluid restriction, daily weights, dialysis.

Rehydration

Process of restoring fluid balance; methods include oral water or sports drinks; dosing commonly 50-100 ml/kg over 4 hours.

Crystalloids

IV fluids with small molecules (electrolytes) that rapidly move between compartments; examples: normal saline (0.9% NaCl) and lactated Radring (LR).

Colloids

IV fluids containing larger molecules that stay in the intravascular space longer to expand plasma volume; examples: albumin, dextrans, hetastarch.

Regulation mechanisms

Body systems that regulate fluid balance, including thirst, ADH (vasopressin), and osmosis.

Thirst

Drive to drink fluids; triggered by increased osmolality or decreased circulating volume as part of fluid regulation.

ADH (vasopressin)

Antidiuretic hormone released by the posterior pituitary; promotes renal water reabsorption to regulate serum osmolality and fluid balance.

Osmosis

Movement of water across a semipermeable membrane from areas of lower solute concentration to higher solute concentration, helping determine fluid distribution between compartments.

Hypermagnesemia

Elevated magnesium levels in the blood; may result from supplements or renal impairment; severe cases treated with IV calcium gluconate or calcium chloride to stabilize the heart, plus diuretics or dialysis to remove excess magnesium.

Magnesium supplements

Oral or other magnesium intakes used to treat deficiency or management of Mg-related conditions; can contribute to hypermagnesemia in impaired renal function.

Foods high in magnesium

Dietary sources rich in magnesium (e.g., leafy greens, legumes, nuts, whole grains) that help maintain normal Mg levels.

Fluid compartments

Body fluid distribution: intracellular ~67%, interstitial ~25%, intravascular ~8%; movement between compartments is regulated by osmosis and membrane permeability.