Fundamentals of Nursing II 2 nd year

2. Fundamentals of Nursing II2nd year Unit III: Basic Nursing Concepts Lecture I: Fluids and Electrolytes Lecture II: Acid-Base Balance and Imbalance Dr Naiema Gaber

3. Fluid and Electrolyte Objectives • Explain homeostasis • Discuss homeodynamics of 1-Water Balance (ECF/ICF volumes) 2-Electrolyte Balance (Na+ and K+) • Identify nursing interventions for clients with altered fluids and electrolytes balance.

4. Fluids • Substances composed of freely moving molecules • Have the ability to conform to the shape of the container that holds it • There are different types of fluids in our bodies

5. What is homeostasis? • It is physiologic processes that regulate fluids intake & output as well as movement of water & substances dissolved in it (fluids)between the body compartments

7. What are the factors that influence body fluids?

8. The body fluid composition of tissue varies by • Tissue type (leantissues have higher fluid content than fat tissues) • Gender (males have more lean tissue and therefore more body fluid) • Age (lean tissue is lost with age and body fluid is lost with it)

9. Water is essential for life, HOW??? Water is vital to health and normal cellular function as it is a • medium for metabolic reactions within cells. • transporter for nutrients and waste products. • lubricant. • Help in regulating and maintaining body temperature. 60% of the average healthy adult’s weight iswater

10. INTRACELLULAR FLUID (ICF 63% of fluids) Inside cell Most of body fluid (40% weight) Decreased in elderly EXTRACELLULAR FLUID ECF (37 % of fluids is Outside cell) Intravascular fluid - within blood vessels (5%) Interstitial fluid - between cells & blood vessels (15%) Trancellular fluid -cerebrospinal, pericardial , synovial Major Compartments for Fluids(Distribution of body fluids)

11. Fluids Figure 7.1a

12. Fluids Figure 7.1c

14. Distribution of body fluids

15. Fluids • Extracellular fluids include • Tissue fluid found between the cells within tissues and organs of the body (interstitial) • Plasma, the fluid portion of blood that carries the blood cells (intravascular) • Trans-cellular fluid - cerebrospinal, pericardial , synovial

16. Electrolytes • Body fluid is composed of • Electrolytes which are mineral salts dissolved in water, including for example: • Sodium • Potassium • Chloride • Phosphorus

17. What is meant by ELECTROLYTES? *Substance when dissolved in body fluids charged ions & is able to carry an electrical current conducting electricity. * It can be: • CATION- positively charged electrolyte • ANION- negatively charged electrolyte *No. Cations = No. Anions for homeostasis *Commonly measured in milliequivalents / liter (mEq/L)

18. WHAT IS THE IMPORTANCE OF ELECTROLYTES • Maintaining fluids balance • Contributing to acid-base regulation • Facilitating enzyme reaction • Transmitting neuromuscular reactions

20. MILLIEQUIVALENT (mEq) • Unit of measure for an electrolyte • Describes electrolyte’s ability to combine & form other compounds • Equivalent weight is amount of one electrolyte that will react with a given amount of hydrogen • 1 mEq of any cation will react with 1 mEq of an anion

21. DEFINITIONS • SOLUTE - substance dissolved • SOLVENT - solution in which the solute is dissolved • SELECTIVELY PERMEABLEMEMBRANES - found throughout body cell membranes & capillary walls; allow water & some solutes to pass through them freely

22. It can be by: Movement of Body Fluids and Electrolytes Diffusion? Osmosis? Filtration? Active transport

23. METHODS OF FLUID & ELECTROLYTE MOVEMENT 1- Passive Transport • Diffusion • Osmosis • Filtration 2- Active Transport using energy (ATP)

25. DIFFUSION • Process by which a solute ( ions and molecules) in solution moves as gas or substance • Molecules move from an area of higherconcentration to an area of lower concentration to evenly distribute the solute in the solution • It can be simple or facilitated diffusion

28. FACILITATED DIFFUSION • Involves carrier system that moves substance across a membrane with simple diffusion , (from area of higher concentration to one of lower concentration) • Example is movement of glucose with assistance of insulin across cell membrane into cell

30. OSMOSIS • Movement of the solution =solvent = wateracross a membrane to equalizes the concentration of ions (solute)on each side of membrane • Movement of solvent molecules across amembrane to an area where there is a higherconcentration of solute that cannot pass through the membrane

31. Osmosis Figure 7.4

32. OSMOSIS cont. OSMOSIS

33. OSMOTIC PRESSURE • Pull that draws solvent through the membrane to the more concentrated side (or side with solute ) • It is determined by relative number of particles of solute on side of greaterconcentration

34. COLLOID OSMOTIC PRESSURE OR ONCOTIC PRESSURE • Special kind of osmotic pressure Created by substances with ahigh molecular weight (like albumin)

35. ISOTONIC • ISO - means alike • TONICITY - refers to osmotic activity of body fluids; tells the extent that fluid will allow movement of water in & out cell • Means that solutions on both sides of selectively permeable membrane have established equilibrium • Any solution put into body with the same osmolality as blood plasma.

36. ISOTONIC SOLUTIONS EXAMPLES: • 0.9% sodium chloride solution • 5% glucose • Ringer’s Solution • Lactated Ringer’s Solution

37. Solution of lower osmotic pressure Less salt or more water than isotonic If infused into blood, RBCs draw water into cells ( can swell & burst ) Solutions move into cells causing them to enlarge Solution of higher osmotic pressure 3% sodium chloride is example If infused into blood, water moves out of cells & into solution (cells wrinkle or shrivel) Solutions pull fluid from cells HYPOTONIC HYPERTONIC

38. HYPOTONIC SOLUTIONS • 5% DEXTROSE & WATER • 0.45% SODIUM CHLORIDE • 0.33% SODIUM CHLORIDE

39. HYPERTONIC SOLUTIONS • 3% SODIUM CHLORIDE • 5% SODIUM CHLORIDE • WHOLE BLOOD • ALBUMIN • TOTAL PARENTERAL NUTRITION • TUBE FEEDINGS • CONCENTRATED DEXTROSE (>10%)

42. OSMOLALITY • Measure of solution’s ability to create osmotic pressure & thus affect movement of water (tonicity) • Number of osmotically active particles per kilogram of water • Plasma osmolality is 280-300* mOsm/ kg • ECF osmolality is determined by sodium • MEASURE used in clinical practice to evaluate serum & urine

43. TONICITY Hypotonic Isotonic Hypertonic OSMOLALITYCELL < 270 mOsm/kg Swelling 275-295 mOsm/kg Nothing > 300 mOsm/kg Shrinking IV Fluid Tonicity !!!!

44. Osmolality In Clinical Practice * • Serum 280-300mOsm/kg • Urine 50-1400mOsm/kg • Serum osmolality can be estimated by doubling serum sodium • Urine specific gravity measures the kidneys’ ability to excrete or conserve water

45. Osmolality In Clinical Practice * • BUN - blood urea nitrogen; made up of urea an end-product of protein metabolism. • inc. with protein intake, fever, & sepsis; dec. with starvation, end-stage liver • dx., low protein diet, expanded fluid vol. (as with pregnancy)

46. Osmolality In Clinical Practice * • Creatinine - end product of muscle metabolism; better indicator of renal function; normal level 0.7-1.5 mg/d L • Hematocrit - vol. % of RBCs in whole blood; normal level in male- 44-52% • In female- 39-47%

47. FILTRATION • Movement of fluid and solutes together through a selectively permeable membrane from an area of higher hydrostatic pressure to an area of lower hydrostatic pressure • Arterial end of capillary has hydrostaticpressure > than osmotic pressure so fluid & diffusible solutes move out of capillary

48. HYDROSTATIC PRESSURE • Force of the fluid pressing outward against vessel wall • With blood not only refers to weight of fluid against capillary wall but to force with which blood is propelled with heartbeat • “Fluid- pushing pressure inside a capillary”*

50. ACTIVE TRANSPORT SYSTEM • Moves molecules or ions uphill against concentration & osmotic pressure • Requires specific “carrier” molecule as well as specific enzyme (ATP) • Hydrolysis of adenosine triphosphate (ATP) provides energy needed • Sodium-potassium pump is an active transport system. It moves substances from area of low solutes concentration to a higher one