Review of Fluids and Electrolytes

Intracellular Fluid (ICF)

67% of total body fluid located within cells.

Extracellular Fluid (ECF)

33% of total body fluid located outside cells.

Transcellular Fluid

3% of total body fluid; includes synovial fluid, cerebrospinal fluid, etc.

Osmotic Pressure

The pressure that determines the movement of fluid across semipermeable membranes.

Sodium (Na+)

An extracellular osmole that holds water in the extracellular space.

Potassium (K+)

An intracellular osmole that holds water within cells.

Na+/K+/ATPase

An enzyme that maintains cell volume by regulating sodium and potassium levels.

Oncotic Pressure

The osmotic pressure exerted by proteins in the plasma.

Third Spacing

Accumulation of excess fluid in interstitium or in fluid spaces, leading to edema.

Anasarca

Massive generalized edema due to fluid overload.

IV Hydration Solution

Fluids administered intravenously to restore hydration and electrolyte balance.

Normal Saline (NS)

Isotonic solution commonly used for hydration.

Lactated Ringer's (LR)

Isotonic fluid that contains electrolytes and is used for rehydration.

Maintenance IV Fluids (MIVFs)

Fluids to replace daily losses and maintain hydration.

Holliday-Segar Method

A formula for calculating maintenance fluid requirements based on body weight.

4-2-1 Method

A formula for calculating maintenance IV rate based on body weight.

Sodium Normal Concentration

135-145 mEq/L for adults, children, and newborns.

Potassium Normal Concentration

3.5-5.0 mEq/L for adults.

Hypokalemia

Low potassium levels in the blood, often due to various losses.

Hyperkalemia

High potassium levels in the blood, often due to renal dysfunction.

Pseudo-Hyperkalemia

False elevation of serum potassium due to hemolysis or improper collection.

Hypermagnesemia

Elevated magnesium levels, characterized by respiratory paralysis and AV block.

Hypomagnesemia

Low magnesium levels leading to symptoms like weakness and convulsions.

Hypercalcemia

High calcium levels in the blood, caused by conditions such as cancer.

Hypocalcemia

Low calcium levels linked to vitamin D deficiency and parathyroid issues.

Phosphorous Normal Concentration (Adults)

2.5-4.5 mEq/L.

Hyperphosphatemia

Elevated phosphorus levels often due to renal dysfunction.

Hypophosphatemia

Low phosphorus levels from factors such as starvation and alcoholism.

Calcium-Phosphorous Relationship

Calcium and phosphorus levels are interrelated in metabolic functions.

Corrected Calcium

A calculation to account for calcium levels based on albumin status.

Ionized Calcium (Ca2+)

The biologically active form of calcium that is not bound to proteins.

Fluid Deficit Causes

Includes diarrhea, vomiting, NG aspiration, and excessive insensible losses.

Fluid Overload Causes

Limited renal function, SIADH, and errors in fluid estimation.

Neuro Symptoms of Phosphorous Deficiency

Ataxia, confusion, and paresthesias.

Cardiovascular Symptoms of Calcium Deficiency

Hypotension, prolonged QT interval, decreased myocardial contractility.

Gastrointestinal Symptoms of Hypercalcemia

Constipation and anorexia due to high calcium levels.

Renal Function in Electrolyte Disturbances

Key factor in the regulation and balance of fluid and electrolytes.