FLUIDS AND ELECTROLYTES

DISTRIBUTION OF BODY FLUIDS 2 compartments Intracellular Extracellular

INTRACELLULAR ICF within the cells 40% of body weight

EXTRACELLULAR (ECF) -outside cell INTERSTITIAL-fluid between cells and outside blood vessels INTRAVASCULAR-blood plasma LYMPH ORGAN FLUIDS

ELECTROLYTES Element or compound that separates into ions when dissolved in water or another solvent

CATIONS-positively charged electrolytes ANIONS-negatively charged electrolytes Differs in ICF and ECF but total number in each compartment should be the same Commonly measured in MILLIEQUIVALENTS

MOVEMENT OF BODY FLUIDS Fluids and electrolytes constantly shift compartments to meet metabolic needs Movement depends on cell membrane permeability

DIFFUSION solute in solution moves from area of higher concentration to an area of lower concentration Example-cream poured into black coffee

OSMOSIS movement of water across a semipermeable membrane from area of lower concentration to one of higher concentration. Example-boiling a hot dog

OSMOLARITY ISOTONIC- HYPERTONIC same osmotic pressure solutions expand the body’s fluid volume without causing a fluid shift HYPERTONIC solution of higher osmotic pressure solutions pull fluid from cells

Hypotonic- Solution of lower osmotic pressure Solution moves into cell

HYDROSTATIC PRESSURE Force of the fluid pressing out against a surface

REGULATION OF BODY FLUIDS HOMEOSTASIS- The process that maintains body fluids in balance Hormonal controls Fluid intake Fluid output

FLUID INTAKE REGULATED PRIMARILY THROUGH THIRST MECHANISM Hypothalamus

OSMORECEPTORS Monitor osmotic pressure in blood Osmolality increases-stimulates hypothalamus-thirst occurs Salty foods Hypovolemia-hemorrhage or excessive vomiting

HORMONAL REGULATION ANTIDIURETIC HORMONE-ADH ALDOSTERONE RENIN

ADH-ANTIDIURETIC HORMONE Posterior pituitary gland Prevents diuresis Causes body to save water Works on renal system Returns water to systemic circulation

ALDOSTERONE Adrenal cortex Acts on renal tubule Reabsorption of sodium Leads to water retention Excretion of potassium and hydrogen

RENIN Enzyme Responds to decrease in renal perfusion secondary to decreased blood volume Produces angiotensin I-angiotensin II-vasoconstrictor

OUTPUT REGULATION ORGANS OF WATER LOSS KIDNEYS SKIN LUNGS GI TRACT

KIDNEYS (1200-1500 ml) urine major organs of fluid balance filter 180 L of blood per day

SKIN (500-600 ml) sweat sympathetic nervous system activates sweat glands

LUNGS (400 ml) exhaled Oxygen devices can increase loss

GI TRACT (100-200 ml) lost site of almost all fluid gain 3-6 L is secreted and reabsorbed daily

INSENSIBLE WATER LOSS Continuous Not perceived

SENSIBLE WATER LOSS Excess perspiration Perceived by the client Noted by nurse on inspection

CATIONS

SODIUM Most abundant cation in ECF Maintain water balance Nerve impulse transmission Regulation of acid-base balance Cellular chemical reactions Regulated by diet and aldosterone Normal 135-145 mEq/L

POTASSIUM Predominant in ICF Regulates metabolic activities Glycogen deposits in liver and muscle Transmit nerve impulse Cardiac rhythm Muscle contraction Regulated by diet and renal excretion Body does not conserve well Normal 3.5-5 mEq/L

CALCIUM Stored in bone, plasma and cells 99% in bone 1% in ECF 50% bound to albumin 40% free ionized calcium

CALCIUM Necessary for bone and teeth formation, blood clotting, hormones, cell membrane s, cardiac conduction, nerve impulses and muscle contraction Hypocalcemia- Trousseau’s sign, Chvotek’s sign Normal ionized 4-5 mEq/L (total 8.5-10.5 mg/dl)

MAGNESIUM Enzyme activities, neurochemical activities, cardiac and skeletal muscle excitability Regulated by diet, kidneys and parathyroid hormone Positive Chvostek’s sign if Mag is low Normal 1.5-2.5 mEq/L Definition of CHVOSTEK'S SIGN. : a twitch of the facial muscles following gentle tapping over the facial nerve in front of the ear that indicates hyperirritability of the facial nerve.

ANIONS

CHLORIDE Major anion in ECF Transport follows sodium Regulated by dietary intake and kidneys Normal 95-108mEq/L

BICARBONATE Major chmical base buffer in the body ECF and ICF Essential to acid-base balance Regulated by kidneys Venous-measured as CO2 (normal 24-30 mEq/L

PHOSPHORUS-PHOSPHATE REGULATION Nearly all phosphorus in body exists as phosphate Regulation of acid-base balance Promotes neuromuscular action and carbohydrate metabolism Regulated by diet, renal excretion, intestinal absorption and PTH Inverse relationship with calcium If one rises, the other falls

ACID-BASE BALANCE pH is a measurement of hydrogen ions in arterial blood More hydrogen-more acidic-lower pH Less hydrogen-more alkaline-higher pH

Acid Base Balance Exists when the rate that body produces acids or bases equals the rate they are excreted Necessary to maintain cell membrane integrity Maintains speed of cellular enzymatic reactions Normal arterial blood pH= 7.35-7.45

Carbon dioxide Bicarbonate CO2 Combines with water in the body to create carbonic ACID Regulated by lungs Bicarbonate HCO3 Base Regulated by kidneys

SODIUM IMBALANCES Hypernatremia Hyponatremia Treatment depends on cause Associated with normal, decreased or increased ECF Kidney disease, GI loss, sweating, diuretics Will see Serum Na <135 Will see Urine sp gravity <1.01 Hypernatremia Excess water loss or sodium excess Body attempts to conserve water Ingestion, hypertonic saline, water deprivation

HYPONATREMIA HYPERNATREMIA Apprehension, postural hypotension and dizziness, abd cramps, N/V/D, tachycardia, convulsions, coma Thirst, dry/flushed skin/dry/sticky tongue/mucous membranes, fever, agitation, convulsions, restlessness, irritability

POTASSIUM IMBALANCES Hypokalemia Hyperkalemia Most common Cause-diuretics Little tolerance for fluctuations Hyperkalemia Severe will have marked cardiac conduction problems Primary cause-renal function

HYPOKALEMIA HYPERKALEMIA Diarrhea, vomiting, sweating, excessive IV’s without KCL, diabetic treatment with insulin Weakness, fatigue, decreased muscle tone, distention, decreased bowel sounds, dysrhthmias, paresthesias, weak/irreg pulse Renal failure, FVD, cell damage-burns/trauma, IV’s with KCL, acidosis, potassium-sparing diuretics, rapid infusion of stored blood Anxiety, dysrhthmias, paresthesias, weakness, abdominal cramps and diarrhea

CALCIUM IMBALANCES Hypocalcemia Hypercalcemia Thyroid and parathyroid disease, Vit D deficiency, renal insufficiency Hyperactive reflexes, tetany, muscle cramps , Chvostek’s sign Hypercalcemia Symptom of underlying disease Malignancy, osteoporosis, prolonged bedrest Anorexia, N/V, weakness, low back pain (kidney stones) decreased LOC, personality changes, cardiac arrest

MAGNESIUM IMBALANCES Hypomagnesemia Hypermagnesemia Malnutrition, alcoholism, absorption, diuretics Muscle tremors, hyperactive DTR’s, Chvostek’s sign, confusion, dysrhythmias Hypermagnesemia Renal failure, excess intake Hypoactive DTR’s, decreased depth and rate of resp, hypotension, flushing

CHLORIDE IMBALANCES Hypochloremia Hyperchloremia Vomiting, drainage, diuretics Rarely occur as single disease No single set of symptoms with either Hyperchloremia Increased sodium, or decreased bicarbonate

FLUID IMBALANCES FVD-fluid volume deficit Fever, burns,hge, decreased intake, hypertonic fluids, diuresis Dry MM, poor skin turgor, thirst, confusion, oliguria, dry sticky tongue, increased body temp, flushed skin, convulsions, coma FVE-fluid volume excess CHF, RF, Excessive sodium intake, excess water intake Edema, hypertension, JVD, crackles, taunt and shiny skin, convulsions, coma

NURSING ACTIONS FOR PATIENTS ON IV THERAPY Measure I&O at least Q shift Assess lab values Physical assessment Assess weight (daily) Vital signs Skin turgor

PARENTERAL REPLACEMENT OF FLUIDS PERIPHERAL CENTRAL

TYPES OF REPLACEMENT TPN IV SOLUTIONS

TYPES OF IV SOLUTIONS ISOTONIC HYPERTONIC HYPOTONIC

ISOTONIC FLUIDS Same osmotic pressure as blood Expands fluid volume No fluid shift from ICF to ECF

ISOTONIC Dextrose in Water solution- Saline Solution- Dextrose 5% in Water (D5W) Saline Solution- 0.9% sodium chloride (NS) Multiple Electrolyte Solution- Lactated Ringer’s (LR)

ISOTONIC

HYPERTONIC SOLUTIONS Solution of higher osmotic pressure Pulls fluid from the cells Causes cells to shrink

HYPERTONIC FLUIDS D10W 3-5% sodium chloride (NS) D5NS D51/2NS D5LR

HYPERTONIC

HYPOTONIC SOLUTIONS Solution of lower osmotic pressure Solutions move into the cells Causes cells to swell

HYPOTONIC SOLUTIONS 0.45% sodium chloride (½ NS)

HYPOTONIC

Phlebitis Infiltration