Fluid and Electrolytes
Fluid and Electrolytes
Normal physiology
- Maintenance of homeostasis
- Composition of fluids and electrolytes kept within narrow limits
- Water content varies with age, gender, and fat content
Fluid Compartments
- Intracellular fluid (ICF)
- Interstitial
- Intravascular (plasma)
- Extracellular fluid (ECF)
- Transcellular
- Lymph
Calculation of Fluid Gain or loss
- One liter of water weighs 2.2 lbs. (1 kg)
- Body weight change is an excellent indicator of overall fluid volume loss or gain
Electrolytes
- Substances whose molecules dissociate into ions when placed in water
- Cations: positively charged
- Anions: negatively charged
- Concentration of electrolytes is expressed in milliequivalents (mEq)/L
- ICF
- Prevalent cation is K+
- Prevalent anion is PO43-
- ECF
- Prevalent cation is Na+
- Prevalent anion is Cl-