Fluids and Electrolytes

1. Fluids and Electrolytes Staying Balanced Spring 2008

2. Water – H2O • “Universal solvent” • 60% of body’s weight • Cells “haf to have it.” • –Arnold Schwarzenegger

3. How much is that? • 154# person x .60 (60%) = • 92# • Water is approx 8# per gallon • 11 ½ gallons water • (Obese people/ less) • (Thin people/ more) • Infants • Elders

4. Basic Cellular Review • The fundamental unit • Requires: • Cell membrane • Enzymes • Internal membranes • Genetic material

5. Basic tissue types • Epithelial • Connective • Muscle • Nervous

6. The cellular environment • All metabolic reactions occur • The precise regulation of volume and composition of body fluid is essential to health.

7. Body fluid compartments • Intracellular Fluid - ICF • Extracellular Fluid – ECF • Intravascular Fluid- Plasma • Interstitial Fluid

8. Intracellular - ICF • Fluid in all body cells • 75% of the water (60%) • 31.50 L (70 kg adult) • 40% of total body weight

9. Extracellular - ECF • 20% of water (60%) • 10.50 L (70 kg adult)) • Includes intravascular and interstitial compartments

10. ECF • Intravascular • 4% of (60%) • 7.5 L

11. ECF • Interstitial • 16% of (60%) • 17.5 L • Fluid between cells and outside the vascular bed • Connective tissue, cartilage, bone, CSF, intraocular fluid

12. Hydration • Water - Universal solvent • Intake & Output (I&O)

13. Hydration • Homeostasis • The body’s need for balance

14. Aging and distribution of fluids • Newborns – TBW ~ 80% • Children – TBW ~ 60-65% • Elders – TBW < ~ 60%

15. Food - 1200 ml Drink - 1000 ml Metabolic sources - 300 ml = 2500 ml Lungs - 400 ml Kidneys - 1500 ml Skin - 400 ml Intestine (Feces) - 200 ml = 2,500 ml Intake vs Output

16. Hydration • Osmoreceptors - anterior hypothalamus • Baroreceptors - carotid sinus, aortic arch, kidneys • High and low blood pressure

17. Hydration • Anti-diuretic hormone (ADH) • If tide goes out • Pituitary Gland Excretes • Tide comes in!!! • Re-absorb from kidneys • Decrease urine • Thirst also regulates

18. Dehydration • Abnormal decrease in TBW • Thus the weigh-in at fires • Rarely involves only water loss • Electrolyte loss

19. Dehydration causes • Signs and symptoms? • Treatment?

20. Causes of dehydration • GI losses • N/V/D • Insensible losses • Normal losses + with fever • Hyperventilation • High Environmental Temps • Increased sweating

21. Causes of dehydration • Internal losses • “Third”spacing • Peritonitis • Pancreatitis • Malnourished • No protein to retain water

22. Causes of Dehydration • Plasma losses • Burns • Surgical Drains • Open wounds

23. Signs and symptoms • Signs of shock • Skin changes (turgor) • Orthostatic hypotension • Thirst • Increased pulse rate • Furrowed tongue

24. S/S, cont. • Decreased BP • Dry mucosa • Infants: Anterior fontanelle sunken • Dry diapers • Absent tears • Cap refill > 2 seconds • Dry mucosa

25. Treatment • ABCs • O2 • Fluids • Flavor? • Consider PASG • ECG

26. Overhydration – “No thanks I’m full.” • Edema • Peripheral vs. central (more later…) • Aggressive treatment if Pulmonary Edema

27. Overhydration • ABCs • O2 • Consider ETT • Meds: • NTG. • Lasix • M.S.

28. Medical causes Diabetes Heat Emergencies Blood Loss Traumatic causes Blood loss Fluid & Electrolyte Disturbances

29. Electrolytes • In H2O dissociate into ions • Cations = positive • Anions = negative

30. Sodium (Na+) Prevalent in ECF “Water follows it” Nerve impulses Hyper/ Hyponatremia Potassium (K+) Prevalent in ICF Nerve impulses Hypo/ Hyperkalemia Principle CationsSodium-Potassium Pump

31. Other Cations • Calcium (Ca++) • Prevalent in ICF • Muscle contraction • Nerve impulse • Hypo/hypercalcemia

32. Other Cations • Magnesium (Mg++) • Present in ICF • Necessary for many processes • Found in some: • Antacids • Laxatives • Most associated with phosphate • Renal Functions

33. Principal Anions • Chloride (Cl-) • Present in ECF • Balances cations • Fluid balance • Renal function • Usually found hanging around sodium

34. Principal Anions • Bicarbonate (HCO3-) • Found in ECF • The Buffer • Neutralizes Acidic (H+) • Tx for acidosis

35. Anions • Phosphate (HPO4--) • Found in ICF - buffer • Energy stores • Mg++ in renal function

36. Electrolytes - mEq/L • Non-Electrolytes - • Glucose • Urea • Proteins

37. How does it get there? • Osmosis • Diffusion • Active Transport • Facilitated Diffusion

38. Isotonic • Hypertonic • Hypotonic • Osomotic gradient - difference in concentration

39. Osmosis • Movement of water (solvent) • Semi-permeable membrane • Towards highersoluteconcentration

40. Diffusion • Movement of solutes • Across membrane • Towards lesser solute concentration

41. Active transport • Movement of solutes • Across membrane • Against osmotic gradient • Requires energy (ATP) • Sodium-potassium pump

42. Active transport

43. Facilitated diffusion • Helper proteins • Insulin • Open gate • Glucose

44. Facilitated diffusion

45. Osmotic Pressure • Governs movement of water and solutes across cell membrane • Pressure exerted by concentration of solutes • Pulls from other side of membrane

46. Lysis Crenation

47. Blood Plasma • Colloid osmotic pressure • Plasma • Hydrostatic pressure • Blood pressure • Filtration

48. Edema • Localized • Site of injury • Organ systems - brain, lungs, heart, abdomen • Generalized • Dependent edema • Pitting edema

49. RELATIVE HYDRATION • Body water in interstitial spaces not available for metabolism • Relative dehydration

50. Edema • Decrease in production of plasma proteins • Liver disorder • Burns • Open wounds