Exam 1: MedSurg

Fluid & Electrolyte Balance

Foundation for understanding renal, cardiac, endocrine functions.

Core Electrolytes

Key electrolytes to master: Potassium (K⁺), Sodium (Na⁺), Calcium (Ca²⁺), Magnesium (Mg²⁺).

Functions of Water

Transport medium, temperature regulation, acid-base balance, enzymatic digestion.

Osmosis

Water moves from low to high solute concentration.

Semipermeable Membrane

Allows selective passage of substances; found in cell membranes.

Hypervolemia

Fluid volume excess; can occur due to CHF, renal failure, excess IV fluids.

Euvolemia

Normal fluid volume status.

ADH (Antidiuretic Hormone)

Hormone that promotes water reabsorption in kidneys.

Hypothalamus

Detects increased osmolality and triggers thirst.

Atrial Natriuretic Peptides (ANP)

Hormones released by atria that reduce blood volume by promoting Na⁺ excretion.

Age-Related Sensitivities

Elderly and infants have specific fluid imbalances concerns.

Dilutional Hyponatremia

Low sodium caused by fluid overload.

Active Transport

Energy-requiring movement of molecules against a gradient.

Nephrotoxic Substances

Drugs/substances that can cause kidney damage.

Urinary Incontinence Types

Stress, urge, mixed, overflow, functional, neurologic.

Cystitis

Inflammation of the bladder typically caused by bacterial infection.

Glomerulonephritis

Inflammation of the kidney’s filtering units, often following infections.

Acute Kidney Injury (AKI)

Sudden decline in kidney function, seen as increased creatinine and decreased GFR.

Electrolytes

Charged molecules that facilitate nerve and muscle function.

Osmolality

Measure of solute concentration in blood or urine.

Daily Fluid Intake Requirement

Minimum daily fluid intake is typically 2-3 liters.

Urine Output Normal Range

Normal urine output is approximately 60 mL/hr.