Fluid & Electrolytes Med-Surg Nursing

Intracellular Fluid

Fluid within cell. Most of body's fluids are found within the cell

Extracellular Fluid

Found in the blood vessels in the form of plasma or serum. Intravascular. Interstitial: lymph fluid, digestive secretions, sweat, csf. Mainly responsible for the transport of nutrients and wastes.

Composes 50 -60% of human body

Water

Explain Homeostasis

a tendency to equilibrium or stability in the normal physiological states of the organism.

Ions

Dissolved electrolytes that develop an electric charge when dissolved in water.

Sodium Na

the most abundant electrolyte in the body and the primary electrolyte in the extracellular fluid.

Potassium K

found in the intracellular fluid. Major intracellullar cation. Plays an important role in maintaining fluid osmo & volume within the cell. K+ is essential for normal membrane excitability & nerve impulses. Needed for protein synthesis & breakdown of glyco

Selective permeable membrane

Selective permeablility maintains the unique composition of the body while allowing for the transport of nutrients & wastes to & from cells. . SPM surrounds cells to separate fluid in the cells from fluid in the tissues.

Calcium

Ca+ /phos to form the mineral salts of the bones & teeth. 99% concentrated in bones & teeth. Ca+ promotes normal transmission of nerve impulses & helps regulate normal muscle contraction & relaxation.

Magnesium (Mg+)

Second most abundant cation in the intracellular fluid; involved in the metabolism of carbs & proteins; also important in functioning of heart, nerves & muscles

Electrolyes

A substance that develops an electrical charge when dissolved in water.

Diffusion

the random movement of particles in all directions. A substance that moves from an area of higher conc to an area of lower conc. EX. O2 moving from the alveoli to the pulmonary capillaries.

Active Transport

Requires expenditure of energy from an area of lower conc. to and areo of higher conc. Ex. Carrier proteins can transport substances from lower to higher area.

Filtration

transfer of water & solutes through a membrane from an area of high pressure to and area of low pressure. filtration is necessary process of moving fluid out of the capillaries into the tissue & for filtering plasma through the kidneys.

osmosis

The movement of water across a membrane from a less concentrated solution to a more concentrated solution.

Osmolality

The concentration of a solution determined by the number of dissolved particles per kilogram of water; controls water movement and distribution in the body fluid compartments.

Main regulators of fluid balance

...Kidneys & Circulatory system

Name the hormones that have a major effect on fluid vol. & balance

...Renin & ADH....?

Increased Plasma Osmo stimulates the osmoreceptors in the hypothalmus to triggger this regulatory mechanism

...The sensation of thirst

A good indicator of fluid loss or retention

...Body weight

Condition in the pt's health history that might put pt. at risk for fluid & electorlyte imbalance.

...Vomiting, diarrhea,kidney diseases,diabetes, salicylate poisoning,burns, congestive heart failure, cerebral injuries, ulcerative colitis, and hormonal imbalance

Characteristics of Urine that we observe include these.

...pH, specific gravity, osmolality, creatinine clearance, urine sodium, urine potassium.

Skin characteristics that we look for in our pt.

...color, moisture, turgor, temperature, puffy or sunken eyes, edema

H2O & Na retention in the tissues; results from excessive reabsorption or inadequate secretion of of Na.

...Edema AEB kidney failure...test by pitting, rate 1+ - 4+, if severe and greater than this, it is called brawny edema (or hard)

Typical care for a pt. with edema includes what?

...Weight & I.O. monitoring.....?

Indicator of H+ ions in the urine.

...pH

Indicator of fluid balance; it it is high, the urine is highly concentrate as in fluid vol. deficit; it is low, the urine is dilute as in fluid vol. excess.

...specific gravity. reflects concentration of urine and renal function.

Used to detect glomerular damage in the kidneys

...Creatininine clearance. Normal range: male 85 -125 ml/min & female 75 - 115 ml/min

Used to measure renal tubular function.

...urine K+ 25-123 mEq/24h

Normal is 8 - 20 mg/dl. Provies a measurement of renal function.

BUN > high BUN = associated with fluid vol. deficit & low BUN with fluid vol. excess.

A plasma protein that maintains blood volume by creating colloid osmotic pressure.

Albumin > normal range = 3.5 - 5.5 g/dl

Causes of fluid vol. deficit

...Hypovolemia> abn. fld losses, excessive bleeding, vomiting, diarrhea, burns
Dehydration

Indicator of dehydration in the elderly.

...decreasing urine output, heart rate increases, bp may fall.

Causes of fluid volume excess.

...extracellular fluid excess ( isotonic fluid excess )
intracellular water excess (hypotonic fluid excess)

Sodium deficit caused by vomiting, diarrhea, diaphoresis.

...excessive water intake without na+, vomiting, diarrhea or diaphoresis with only water replacement; use of distilled water to irrigate body cavities; and excess secretion of ADH.

Symptoms of hyponatremia

...headache, muscle weakness, fatigue, apathy, confusion, abd. cramps, & orthostatic hypotension.

Symptoms of hypernatremia

...thirst, flushed skin, dry mucous membranes, low urine output, restlessness, increased heart rate, confulsions & postural hypotention.

Foods included in a low sodium diet.

...fresh fruits, grains; unsalted pasta, oatmeal, unsalted popcorn, ruffed rice, shredded wheat. Meats: fresh, chicken, fish

Can be caused by vomiting, diarrhea, nasogastric suction, inadequate intake of K+ & K= wasting diuretics.

...HypoKalemia

Signs & Symptoms of Hypokalemia

...anorexia,abd distention, vomiting, diarrhea, muscle cramps, weakness, dysrhythmias, postural hypotension,

List the causes of hypoCalemia.

...vomiting,diarrehea, nasogastric suction, inadequate dietary intake of K+, diabetic acidosis, excessive aldosterone secretions, drugs such as K+ wasting diurectics and corticosteroids.

Normal blood pH. Acid, alkaline?

...7.35 -7.45 acid < 7.35 and alkaline > 7.45

Acid base imbalance that occurs when the respiratory system fails to eliminate the appropriate amount of CO2

respiratory acidosis.....low pH....high pCO2

When excessive amounts of CO2 are eliminated via the lungs.

respiratory alkalosis.....high pH.....low pCO2

Occurs when the body retains too many H+ ions & losses too many bicarb ions.

...metabolic acidosis...low pH....low HCO3

S&S of metabolic acidosis

...changing levels of consciousness, ranging from fatigue & confusion to stupor & coma, headache, vomiting, diarrhea, muscle weakness and cardiac dysrhythmias.

Effects of Hypotonic solutions on the cell.

...cells will swell up

Effects of Hypertonic solutions on the cell.

...cells will shrink

Effect of isotonic solutions

...Normal concentration of fluids

Solutions that have the same conc. as body fluids & the same osmotic pressure as plasma are called this.

...Tonicity, a measure of the concentration of electrolyes in the fluid.
Solutions that have the same conc. as body fluids are called istonic.

Signs of IV infiltrations.

...pain or burning sensation, the site may be pale & puffy. If a lot of fluid is in the tissue, it may feeel hard & cool.

Signs of inflammation & infection of an iv site.

...Irritation by the cannula or by medications. Redness, swelling, warmth, & tenderness near the insertion site suggest phlebitis. An infected site may have purulent drainage and the patient might have a fever. Inflammation may be mild or severe & carries

signs of fluid overload related to IV infusion too fast.

...rising blood pressure, bounding pulse, and edema. Severe fluid volume excess produces congestive heart failure & pulmonary edema.

Results from an increase in Bicarb. levels or a loss of H+ ions.

...Metabolic alkalosis....increase in bicaronate levels or a los of H+ ions.

Signs of metabolic acidosis

...changing levels of consciousness, ranging from fatigue & confusion to stupor & coma, headache, vomiting, diarrhea, muscle weakness and cardiac dysrhythmias.

Metabolic alkalosis

High pH.....High HCO3

Acid-base balance

refers to homeostasis of the hydrogen ion (H+) concentration in the body fluids. A solution containing a higher number of H+ ions is acid, and opposite, i.e., low number of H+ ions = alkaline or base.

Acid-base balance is maintained by 3 mechanisms:

1. buffers
2. respiatory control of CO2
3. renal regulation of bicarb, HCO-3

Principle buffers in renal tubular fld

Ammonia and phosphate>>> others are proteins and hgb.

Buffers systems comprise

A weak acid and a salt.

Lungs are primarily responsible for regulation of:

Carbon dioxide (CO2) in the blood, controlled by rate & depth of respirations.

Carbonic acid is broken down into:

H2O & CO2, & eliminated by exhalation.

Kidneys regulate pH by:

Excreting acid or bases as needed. Kidneys produce & reobsorb bicarb. Regulation of HCO3 & excretion of H+ ions regulate acid-base balance through the kidneys.

Respiratory acidosis occurs when respiatory system fails to:

Eliminate the appropriate amt. of CO@ to maintain the a-b balance.CO2 retained with resultant accumulation oc carbonic acid and decrese in blood pH.

Acute respiratory acidosis is caused by:

Resp. diseases i.e. pneumonia, drug overdoses, head injury, chest wall injury, obesity, asphyxiation, drwning or acute respiratory failure.

S& S of Respiratory acidosis:

Rapid heart rate, headache, sweating, lethargy, & confusion.

Respiratory Alkalosis

Marked by low PaCO2 with risultant rise in pH. Characterized by rapid or deep respirations that cause excessive amounts of CO2 to be eliminated through the lungs. A cause can be anxiety. Others; decreased O2 by pneumonia, adult respiratory distress syndro

S&S of Resipratory Alkalosis

Increased respiratory and heart rates. Anxious appearance, irritability, dizziness, lighjtheadedness, muscle weakness, & tingling or numbness of fingers. Confusion, fainting, or seizures.

Metabolic Acidosis

Body retains too many H+ ions or loses too many bicarb ions. With too many H+ or too little bicarb, pH will fall. Met. Acid leads to hyperventilation because the lungs try to compensate by blowing off CO2 & lowering O2 levers which raises the pH.

Causes of Metabolic Acidosis:

Starvation, dehydration, diarrhea, shock, renal failure, and diabetic ketoacidosis.

S&S of Metabolic Acidosis:

Changing leves of consciousness, ranging from fatigue, & confusion to stupor & coma, headache, vomiting & diarrhea, anorexia, muscle weakness & cardiac dysrhythmias.

Metabolic Alkalosis

Opposite of Metabolic acidosis. Increase in HCO3 or a loss of H+ ions. Loss of H+ ions may be caused by prolonge nasogastric suctioning, vomiting, diuretics, & electrolyte disturbances. Retention of HCO3 may be result from admin of HCO3 or massive blood t

S&S of Metabolic Alkalosis:

headache, irritability, lethargy, changes in lvevel on consciousness, confusion, changes in heart rate, slow shallow resp. with periods of apnea; nausea & vomiting, hyperactive reflexes and numbness of extremities.