FLUIDS AND ELECTROLYTES Carolyn Frye -Shegog Physiology: body fluids is composed primarily of water and electrolytes. An electrolyte is defined as a substance that develops an electrical charge when dissolved in water. It is essential to the correct functioning of the body to maintain a precise balance among the fluids and the substances dissolved in the fluids. The human body is composed of many different solutions located in various compartments. The human body is composed of millions of cells, with each having a particular function. In relation to fluids and electrolytes, when we speak of balance we are referring to the distribution of components, such as nutrients, oxygen, hormones and enzymes, throughout the various parts of the body according to their needs. The cell membrane normally control substances entering and leaving the cell to maintain its balance. There are multiple relationships that exist to maintain balance, regardless of the many changes in the internal and external environments. There is an interdependence between the fluids, electrolytes, acids and bases. Body fluids are in constant motion, maintaining healthy living conditions for body cells. The extracellular (ECF) interfaces with the outside world and is modified by it, but the intracellular fluid (ICF) remains stable. Nutrients are transported by the ECF to the cells, and wastes are carried away from the cells by means of the capillary bed. In the typical adult, approximately 60% pf weight consists 0f fluid (water and electrolytes). This fluid is either intracellular (within the cells) or extracellular (outside the cells) extracellular fluid (ECF) is further subdivided into: Intravascular fluid (plasma) within the blood and lymphatic vessels transports substances to and from the interstitial fluid. Interstitial fluid (fluid lying between the cells, or tissue fluid). Between the vessels and the cells and acts as a transport medium between the vascular system and the cells. ECF is also present in areas referred to as THIRD SPACE FLUIDS: third space fluids are those ECF fluids collected in various parts of the body because of injury, infection, or compromised circulation. They are not available for functional use. Example of third space body fluids are fluids found in: Plural space Pericardial Peritoneal Joints intestinal fluid. In disease states the fluids can increase and produce pleural effusion, pericardial effusion, ascites, and joint effusion. The term third space fluids may also apply to interstitial fluid that accumulates following trauma to soft tissue. For example, fluid may accumulate locally following a severe burn or abscess. This fluid does not contribute to the usual exchange of intracellular and extracellular fluids. Protein: because protein deficit causes changes in the location of ECF, a brief discussion of protein is necessary. Individuals need to remain in positive nitrogen balance so that protein anabolism exceeds protein catabolism. Neutral nitrogen balance occurs when protein intake equals protein output. Positive nitrogen balance occurs when protein intake is greater than protein output. Negative nitrogen balance occurs when protein intake is less than protein output: It may develop when 1)protein intake is inadequate. 2)available protein is not conserved (patients with kidney disease who have proteinuria.) or 3) the need for protein is increased (as in severe trauma or burns). Protein is located in both ECF and ICF. The normal range for serum protein is 6 to 8.4gm/100ml.

PHYSIOLOGY Body fluids Body compartments Variations in fluid content Electrolytes

FUNCTIONS OF BODY FLUID: Provides a medium for transporting nutrients to cells and wastes from cells and for transporting substances such as hormones, enzymes blood plates, and red and white blood cells. Facilitates cellular metabolism and proper cellular chemical functioning Acts as a solvent for electrolytes and non electrolytes

Functions of body fluid con’t Helps maintain body temperature Facilitates digestion and promotes elimination Acts as a tissue lubricant

BODY FLUIDS: Water as a percent of body weight Infants = 77% Adult male=60% Adult female= 50% Elderly person =45%

BODY FLUIDS COMPARTMENTS: Intracellular Extracellular Interstitial intravascular

VARIATIONS IN FLUID CONTENT Age Sex Amount of body fat

ELECTROLYTES Electrolytes are substances whose molecules dissociate or split into ions when placed in water. Some develop a positive charge, others a negative charge. Ions with a positive charge(+) are cations. Ions with a negative charge(-) are anions.

FLUID AND ELECTROLYTE MOVEMENT: Diffusion Facilitated diffusion Active transport Osmosis Hydrostatic pressure Oncotic pressure (reabsorption) “keeping the fluid in”

FLUID BALANCE: Elevation of venous hydrostatic pressure Decrease in the plasma oncotic pressure Elevation of interstitial oncotic pressure

ORGANS OF REGULATION KIDNEYS LUNGS HEART BLOOD VESSELS PITUITARY ADRENAL CORTEX PARATHYROIDS

ACID BASE BALANCE: Buffers attempt to bring a body fluid as close as possible to the Ph of normal body fluid Carbonic Acid-Sodium Bicarbonate system and other buffer systems affect: The kidneys Plasma protein Globins portion of hemoglobin

ASSESSING: Nursing history Physical Assessment Acid-Base imbalances (ABGs)

NURSING DIAGNOSES: Fluid volume excess Fluid volume deficit Risk for fluid volume deficit

PLANNING: Expected Outcomes Maintain an approximate balance between fluid intake and output Maintain a urine specific gravity within normal range (1.010 – 1.025)

IMPLEMENTING to prevent or correct imbalances include: Dietary modification Modification of fluid intake Medication administration IV therapy Blood and blood product replacement Total Parenteral Nutrition (TPN)

EVALUATING: Drinking and eating patterns supplying fluid and electrolyte needs Urine output = to fluid intake Color, odor & specific gravity indicate healthy functioning of the kidney Fluid balance wt. I & O Initial signs or symptoms improved Pt’s ability to practice self-care behaviors