1. 1 Fluid and Electrolyte Imbalances

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3. 3 Body Fluid Compartments 2/3 (65%) of TBW is intracellular (ICF) 1/3 extracellular water –25 % interstitial fluid (ISF) – 5- 8 % in plasma (IVF intravascular fluid) –1- 2 % in transcellular fluids – CSF, intraocular fluids, serous membranes, and in GI, respiratory and urinary tracts (third space)

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5. 5 Fluid compartments are separated by membranes that are freely permeable to water. Movement of fluids due to: – hydrostatic pressure – osmotic pressure\ Capillary filtration (hydrostatic) pressure Capillary colloid osmotic pressure Interstitial hydrostatic pressure Tissue colloid osmotic pressure

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7. 7 Balance Fluid and electrolyte homeostasis is maintained in the body Neutral balance: input = output Positive balance: input > output Negative balance: input < output

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10. 10 Solutes – dissolved particles Electrolytes – charged particles –Cations – positively charged ions Na +, K +, Ca ++, H + –Anions – negatively charged ions Cl -, HCO 3 -, PO 4 3- Non-electrolytes - Uncharged Proteins, urea, glucose, O 2, CO 2

11. 11 Body fluids are: –Electrically neutral –Osmotically maintained Specific number of particles per volume of fluid

12. 12 Homeostasis maintained by: Ion transport Water movement Kidney function

13. 13 Tonicity Isotonic Hypertonic Hypotonic

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15. 15 Cell in a hypertonic solution

16. 16 Cell in a hypotonic solution

17. 17 Movement of body fluids “ Where sodium goes, water follows.” Diffusion – movement of particles down a concentration gradient. Osmosis – diffusion of water across a selectively permeable membrane Active transport – movement of particles up a concentration gradient ; requires energy

18. 18 ICF to ECF – osmolality changes in ICF not rapid IVF → ISF → IVF happens constantly due to changes in fluid pressures and osmotic forces at the arterial and venous ends of capillaries

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20. 20 Regulation of body water ADH – antidiuretic hormone + thirst –Decreased amount of water in body –Increased amount of Na+ in the body –Increased blood osmolality –Decreased circulating blood volume Stimulate osmoreceptors in hypothalamus ADH released from posterior pituitary Increased thirst

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22. 22 Result: increased water consumption increased water conservation Increased water in body, increased volume and decreased Na+ concentration

23. 23 Dysfunction or trauma can cause: Decreased amount of water in body Increased amount of Na + in the body Increased blood osmolality Decreased circulating blood volume

24. 24 Edema is the accumulation of fluid within the interstitial spaces. Causes: increased hydrostatic pressure lowered plasma osmotic pressure increased capillary membrane permeability lymphatic channel obstruction

25. 25 Hydrostatic pressure increases due to: Venous obstruction: thrombophlebitis (inflammation of veins) hepatic obstruction tight clothing on extremities prolonged standing Salt or water retention congestive heart failure renal failure

26. 26 Decreased plasma osmotic pressure: ↓ plasma albumin (liver disease or protein malnutrition) plasma proteins lost in : glomerular diseases of kidney hemorrhage, burns, open wounds and cirrhosis of liver

27. 27 Increased capillary permeability: Inflammation immune responses Lymphatic channels blocked: surgical removal infection involving lymphatics lymphedema

28. 28 Fluid accumulation: increases distance for diffusion may impair blood flow = slower healing increased risk of infection pressure sores over bony prominences Psychological effects

29. 29 Edema of specific organs can be life threatening (larynx, brain, lung) Water is trapped, unavailable for metabolic processes. Can result in dehydration and shock. (severe burns)