Fluid & Electrolyte Balance Flashcards
What do nurses need to know about fluid and electrolyte imbalance to provide safe and competent nursing care?
Fundamental question because many disease & clinical conditions result in alterations
Homeostasis
- a state of equilibrium within the body
- naturally maintained within certain limits
- when we measure potassium or sodium in the blood there is a normal parameter
- people fall outside those boundaries sometimes (clinical manifestations)
- self-regulated process to maintain fluid balance, electrolyte balance, and acid base balance
fluid balance
- hypovolemia
- hypervolemia
- third spacing
- fluid follows electrolytes
when homeostasis is lost we need to:
help the body return to its normal state
what percent of normal body weight is taken up by water
55-60%
newborn
80%
Toddler
70%
Child
65%
adult man
60%
Adult woman
55%
Seniors
50-55%
Body Fluid Compartments
Intracellular
Extracellular
Transcellular
Intracellular (ICF)
- 70%
- low in Na+
- High in K+
- Fluid located within the cells
Extracellular (ECF)
- 2 components
- 30%
1. plasma (intravascular)
2. Interstitial (between cells & lymph) - Transcellular - CFS, GI tract & pleural, synovial and peritoneal spaces (can become a third space)
- high in Na+
- low in K+
Electrolytes
- substances whose molecules dissociate into ions (charged particles) when placed in water
Cations
positively charged
Anions
negatively charged
Electrolyte Composition of Fluid Compartments ICF
- Prevalent cation is K+
- Prevalent anion is PO4
Electrolyte Composition of Fluid Compartments ECF
- Prevalent cation is Na+
- Prevalent anion is Cl-
Mechanisms Controlling Fluid and Electrolyte Movement
- Diffusion
- Facilitated diffusion
- Active transport
- Osmosis
- Hydrostatic pressure
- Oncotic pressure