NURS 2821 FINAL - shoutout EVAN FN

Interstitial Fluid

• Fluid between cells

Intravascular Fluid

• Plasma within blood vessels

Transcellular Fluid

• Specialized fluids (CSF, pleural, synovial)

Thirst Mechanism

• Controlled by hypothalamus

• Triggered by increased osmolality or decreased blood volume

Antidiuretic Hormone (ADH)

• Promotes water reabsorption in kidneys

• Decreased urine output

Renin-Angiotensin-Aldosterone System (RAAS)

• Increases sodium & water retention

• Increased blood volume

Atrial natriuretic peptide (ANP)

• Causes excretion of sodium & water

• Decreased blood volume

Insensible Loss

• Fluid loss not measurable (sweat, lungs)

Sensible Loss

• Measurable loss (urine, stool)

Hypovolemia

• Deficit of water and electrolytes in ECF

Dehydration

• Loss of water with electrolyte imbalance

Third Spacing

• Fluid shifts into nonfunctional spaces (e.g., burns)

Hypervolemia

• Excess fluid and sodium in ECF

Edema

• Fluid accumulation in interstitial spaces

Sodium

• Regulates ECF volume

• Normal range: 136–145 (HIGHEST)

Potassium

• Regulates cellular function & cardiac activity

• Normal range: 3.5-5

Calcium

• Muscle contraction, nerve transmission, clotting

• Normal range: 9-10.5

Magnesium

• Enzyme function, metabolism

• Normal range: 1.3-2.1 (LOWEST)

Chloride

• Maintains osmotic pressure in blood

• Normal range: 98-106

Bicarbonate

• Primary buffer system

Phosphorus/Phosphate

• Involved in important chemical reactions in the body, cell division, and hereditary traits

• Normal range: 3-4.5

• Cell metabolism & energy processes

Adrenal Glands

• Regulate sodium & potassium

Pituitary Glands

• Releases ADH

Parathyroid Gland

• Regulates calcium

Osmolality

• Concentration of particles in fluid

Isotonic fluid

• Same concentration as plasma

Hypertonic fluid

• Higher concentration

• Pulls water out of cells

• Hypernatremia

Hypotonic fluid

• Lower concentration

• Water enters cells

• Hyponatremia

Osmosis

• Water moves from low solute to high solute

Diffusion

• Solutes move from high to low concentration

Active Transport

• Movement against gradient using energy

Capillary Hydrostatic Pressure

• Pushes fluid out of capillaries

Oncotic Pressure

• Pulls fluid into capillaries

Acid

• Releases hydrogen ions (H⁺)

• Ex: Acidosis = Excess H⁺

Base

• Accepts hydrogen ions

Alkalosis

• Deficit of H⁺

Buffer System

• Immediate regulation

• Bicarbonate (PRIMARY), protein, phosphate

Respiratory Acidosis

• Increase CO₂ = Hypoventilation

Respiratory Alkalosis

• Decrease CO₂ = Hyperventilation

Metabolic Acidosis

• Decrease bicarbonate

Metabolic Alkalosis

• Increase bicarbonate

Key Assessments

• I&O, daily weight, labs, vitals

Signs of Dehydration

• Dry mucosa, tachycardia, hypotension, oliguria

Signs of Overhydration (fluid overload)

• Edema, crackles, JVD

Colloids

• Pull fluid into vascular space

• Ex: albumin (natural)