Chapter 13 And 15 Fluid Electrolytes Basics
- 1. Fluid and Electrolytes Basics Peggy D. Johndrow 2009
- 2. Fluid Compartments Intracellular fluid (ICF) Extracellular fluid (ECF) Intravascular (plasma) Interstitial Transcellular Cerebrospinal fluid Gastrointestinal (GI) tract Pleural spaces Synovial spaces Peritoneal fluid spaces
- 3. Fluid and Electrolyte Movement Diffusion Facilitated Diffusion Active Transport Osmosis Measurement of Osmolality Osmotic Movement of Fluids Hydrostatic Pressure Oncotic Pressure
- 4. Filtration Blood pressure - hydrostatic filtering force Difference between hydrostatic pressure of capillary bed and interstitial determines whether fluid leaves the blood vessels and enters the tissue spaces (interstitial fluid)
- 5. Diffusion Diffusion - free movement of most electrolytes, atoms, and molecules through cell membranes (selective and impermeable) Movement of molecules from an area of high concentration to low concentration; occurs in liquids, solids, and gases Membrane separating two areas must be permeable to substance for diffusion to occur
- 6. Diffusion
- 7. Facilitated Diffusion Very similar to diffusion Specific carrier molecules involved to accelerate diffusion Glucose cannot cross the cell membrane without insulin
- 8. Osmosis Osmosis and filtration act together in capillary fluid dynamics to control extracellular fluid (ECF) and intracellular fluid (ICF) volumes Thirst mechanism - example of how osmosis helps maintain homeostasis
- 9. Active Transport Cells use active transport to control cell volume and intracellular concentrations of many substances Process in which molecules move against concentration gradient Example: sodium-potassium pump ATP is energy source
- 11. Fluid Movement in Capillaries Fluid Shifts Shifts of Plasma to Interstitial Fluid Elevation of venous hydrostatic pressure Decrease in plasma oncotic pressure Elevation of interstitial oncotic pressure Shifts of Interstitial Fluid to Plasma
- 12. Regulation of Water Balance Hypothalamic Regulation Pituitary Regulation Adrenal Cortical Regulation Renal Regulation Cardiac Regulation Gastrointestinal Regulation Insensible Water Loss
- 13. Sodium (Na) Normal plasma sodium level 136 - 145 mEq/L Sodium - major cation in extracellular fluid; responsible for maintaining extracellular fluid (ECF) osmolarity; responsible for skeletal muscle and cardiac contraction, nerve impulse transmission, normal extracellular fluid osmolarity and normal extracellular volume
- 14. Calcium (Ca++) Calcium levels 9.0 - 10.5 mg/dL Calcium: important in maintenance of bone strength and density, activation of enzymes or reactions, skeletal and cardiac muscle contraction, nerve impulse transmission, and blood clotting
- 15. Phosphorous (P) Phosphorous plasma levels 3.0 - 4.5 mg/dL Phosphorous function: activating B-complex vitamins, forming and activating ATP, assisting in cell division, and cooperating in CHO, protein, and lipid metabolism Phosphorous balance and calcium balance inverse proportion
- 16. Magnesium (Mg2+) Free magnesium plasma levels 1.3 - 2.1 mg/dL Functions: skeletal muscle contraction. carbohydrate metabolism, adenosine triphosphate formation (ATP), B-complex vitamin activation, DNA and protein synthesis Extracellular magnesium regulates blood coagulation and skeletal muscle contractility
- 17. Chloride (Cl) Chloride normal plasma level 98 -106 mEq/L Functions: works with sodium to maintain extracellular fluid osmotic pressure, important in the formation of hydrochloric acid in stomach, bicarbonate anion most commonly exchanged for chloride
- 18. Assessment Fluid Electrolyte Balance History Medical/surgical history Medication Food/fluid Physical assessment S/S edema, dehydration, electrolyte imbalance Psychosocial assessment Diagnostic assessment Lab studies: blood, urine