Chapter 18 Fluids and Electrolytes
hydrogen ion concentration and the pH level: (acidity and alkalinity)
- hydrogen ions increase= the acidity of the solution increases and the pH decreases. -The opposite happens with alkalinity: the number of hydrogen ions decreases and the pH increases.
Purpose of electrolytes in the body :
- maintenance of normal body metabolism -regulation of water balance in the body -regulation of water and electrolyte contents within cells -formation of hydrochloric acid in gastric juice
Osmosis (passive transport)
-Diffusion of water through a selectively permeable membrane -the goal is to reach equilibrium -diffusion of water molecules into and out of cells to correct imbalances -(think of osmosis as the "wet' version of diffusion) -low concentration to high concentration ex: ***Lasix reduces edema by drawing water from the interstitial space into the intravascular space. **Osmosis is the movement of water from an an area of low -high concentration.
Hypernatremia
-High sodium in the blood CAUSES: -abnormal intake of Na+/ ordecrease in body water -consumption of antacids containing Na+ -rapid IV saline infusion -body tries to correct imbalance by conserving water through renal re-absorption SIGNS/SYMPTOMS -dry mucous membranes -low urinary output -restlessness, confusion, agitation -tachycardia, hypotension, death INTERVENTIONS: -decrease Na+ intake in diet -monitor vitals (esp BP, Pulses) -monitor for increased respiratory rate -I&O -weight pt -Hypotonic solution
Nclex: How do diuretics work on an edema patient ?
-Push sodium out into urine to make water exit the body -Reduces blood volume, edema, BP
active transport
-Requires ATP (energy) -move substances from low concentration to high concentration -referred to "chemical pump" -ex: sodium potassium pump
Three systems that the work to keep the pH in the narrow range of normal are:
-blood buffers -respiratory system -kidneys
passive transport
-does not require energy from the cell -moves from area of low concentration to high concentration 3 types of processes - diffusion, osmosis, filtration
substance that develops an electrical charge when it dissolves in water:
-electrolyte -these electrical charges are called ions (positively charged-cations) (negatively charged-anions) they balance each other out (homeostasis)
sodium-potassium pump
-example of active transport -it is the body's way of maintaining the sodium-potassium balance (sodium is extracellular, potassium is intracellular , the "pump" allows both to flow freely through the membrane.)
Input/Output
-fluid leaves the body through kidneys, skin, lungs, and GI
Hyperkalemia
-high potassium in the blood ↑ -overstimulation of the cardiac muscle may lead to cardiac arrest **** CAUSES: -adrenal insufficiency (aldosterone reg. blood and sodium in the body) -renal failure (Ka+ not excreted) -beta blockers -NSAIDS SIGNS/SYMPTOMS: -cardiac dysrhythmias -irregular pulse -hypotension -skeletal muscle weakness (esp LE) INTERVENTIONS: -loop diuretics (Lasix) -decrease foods high in potassium -monitor I&O
Hypokalemia
-low potassium in the blood CAUSES: -renal excretion (the kidneys do not conserve potassium they excrete it even if the body needs it) -GI losses (vomiting, diarrhea suctioning, ileostomy) , diaphoresis -diuretics (ex: Lasix). SIGNS/SYMPTOMS: -cardiac dysrhythmias, weak/irregular pulse -cardiac or respiratory arrest -orthostatic hypotension -polyuria (excessive urine) INTERVENTIONS: -monitor EKG -administer potassium chloride (KCl) -asses pt who are on digitalis (drug to treat heart conditions) - low k+ levels could potentiate digitalis and cause digitalis toxicity -monitor I&O
Hyponatremia
-low sodium in the blood CAUSES: diarrhea, vomiting, excessive water intake (sodium is diluted) , loss of GI fluids -body tries to compensate by retaining water SIGNS/SYMPTOMS: -muscle weakness, twitching, -altered level of consciousness - lethargy, confusion, fatigue coma, seizures, shock (most severe) INTERVENTIONS: -monitor vitals ; esp BP (high Na+ = high BP . Low Na+ =low BP) -monitor I&O -monitor neurologic status -weigh patient daily
Diffusion (passive transport)
-movement of particles from low concentration to high concentration -the goal is to reach equilibrium ex: in haled oxygen is moved into the intravascular compartment .** ( Passive transport occurs when the pt inhales oxygen into the lungs , w/ the oxygen passing by diffusion into the intravascular space)
bicarbonate (HC03-)
-normal range : 22 -24 mEq/L -alkaline electrolyte -kidneys regulate the amount retained or excreted -function :regulate acid base balance
After thyroid sx pt reports nausea, tingling sensation around nose, mouth , ears, fingers and toes. muscle spasms in the pt feet band hands. what are these signs/symptoms associated with?
-patient is showing signs of hypocalcemia (parathyroid glands can be damaged during thyroid surgery and loss of parathyroid hormone interferes with the absorption and utilization of calcium). Laryngeal spasms could occur and cause respiratory arrest.)
What is the recommended Calcium for premenopausal and postmenopausal woman taking estrogen? What is the recommended amount of Calcium postmenopausal woman NOT taking estrogen ?
-premenopausal and postmenopausal woman who are taking estrogen need = 1,000 mg/day -postmenopausal women NOT taking estrogen need 1,500 mg/day
Filtration (passive transport)
-requires a mechanical force -movement of water solutes occur from an area of high hydrostatic pressure to an area of low hydrostatic pressure -ex: In think of kidneys as the "washer machines of body"
arterial blood gas (ABG)
-test that reveals whether the blood is acid, neutral, alkaline hydrogen ion concentration and the pH level: - hydrogen ions increase= the acidity of the solution increases and the pH decreases. -The opposite happens with alkalinity: the number of hydrogen ions decreases and the pH increases.
a loss of _____ % of body fluid is considered fatal
20 %
kidneys excrete a minimum of
30 ml of urine per hour (if number is below REPORT immediately to RN)
normal pH of the blood?
7.35 - 7.45 A pH lower 6.8 = acidosis (fatal) A pH higher than 7.8 = alkalosis (fatal)
which patient has the greatest risk for dehydration ? - 72 yr old obese male w/ fever and anorexia or -2 yr old w/ ear infection and vomiting
72 yr old obese male w/ fever and anorexia Both are at risk but 72-year old obese male has more risk factors; fever causes insensible loss, he is anorexic (loss of appetite) may cause the pt to refuse oral foods or fluid
Diet and fluid restriction and medications have been administered to the patient to decrease excess fluid volume. On the first day of the patient's weight was 150 pounds. After therapy, the patient's weight is 145.5 pounds. Assuming that the weight change represents fluid loss, how much fluid to the patient lose?
=2 liters. (1L=1kg=2.2 lbs) 150 - 145.5 = 4.5 pounds ÷ 2.2 = 2.04 rounded to 2 L
the patient is experiencing HYPERKALIMIA what treatment will the nurse anticipate?
Administering loop diuretics.
Nclex. Why are babies given pedyalyte instead of water to replace fluid loss?
Because babies already have so much water in their bodies Babies are more sensitive to water loss
what is a better source of calcium? dairy or green leafy greens?
Dairy products are the best source of calcium. Calcium is also found in some green leafy vegetables, but these sources are harder for the body to use.
Of all the electrolyte disorders, which disorder is considered the most dangerous and potentially fatal? Hypercalcemia Hypermagnesemia Hyperkalemia Hypernatremia
Hyperkalemia because it can lead to arrhythmia- cardiac arrest
Chvostek's sign
Hypocalcemia - facial muscle spasm upon tapping (causes twitching of the nose/lips )
Patient is experiencing hypernatremia 150mEq/L what type of solution should the nurse administer? -isotonic? -hypertonic? -hypotonic?
IV hypotonic solution to correct intracellular dehydration
The nurse is totaling the I&O at the end of 8 hr shift based on the data recorded: intake: 0800: 8 oz of coffee, 6 oz of juice 1000: 300 ml water 1200: 12 oz of chicken broth , 5 oz of jell-O 1430: 200 ml water output: 0700: 300ml of urine 0930: 450 ml of urine 1400 500ml of urine 1500: 250 ml of urine what is the total intake? _______ml what is the total output? ________ml
Intake: 1430mL; Output: 1500mL (30 ml = 1 oz ) Intake: 240 +180+300+360+150+200 = 1430 ml Output: 300+450+500+250= 1500mL
These solutions are the most commonly used when the electrolyte balance is not the issue, but fluid replacement is needed :
Isotonic solutions
Lasix
Loop Diuretic ***patient is at great risk for hypokalemia*** (usually provider orders potassium to decrease the risk)
Hypomagnesemia
Low magnesium levels CAUSES: malnutrition, diarrhea, starvation , impaired GI absorption SIGNS/ SYMPTOMS: -Seizures, tachycardia, tetany, tremors INTERVENTIONS: -magnesium supplements -asses neuromuscular status -monitor vitals -I&O
Fluid loss-Sensible
Measurable examples: urine, feces, vomiting, wound drainage
Potassium (K+)
Normal Range: 3.5-5.0 mEq/L -mostly found in intracellular fluid Function: -regulate water & electrolytes within the cell - help muscle contract (esp. heart) -help transmission of nerve impulses Excreted mainly by kidneys, feces and perspiration Sources: oranges, apricots, leafy vegetables, potatoes, tomatoes, meat, asparagus, avocado ,cantaloupe , milk , mushrooms
Calcium (Ca++)
Normal levels 8.6-10.2 mg/dl same as 4.5-5.6 mEq/L -excreted through urine and feces Function: -promotes normal transmission of nerve impulses -muscle contraction & relaxation -formation of bones and teeth -prevent osteoporosis -necessary for blood clotting -vitamin D facilitates absorption Sources: dairy, beans, nuts, cauliflower, lettuce, egg yolks
Fluid loss-insensible
Not measurable ex: perspiration , expiration -moisture escaping from the mouth when talking
what individuals are at greater risk for complications resulting in dehydration?
Older adults , babies & Obese (because of the reduced fluid reserve)
Lasix reduces edema by drawing water from the interstitial space into the intravascular space. What is this an example of? -diffusion? -filtration? -osmosis?
Osmosis (mvmt of water from are of low concentration- high concentration)
autologous blood transfusion
Re-infusing the patients own blood. Nclex: Jeahova's witness patient-have the patient come in prior to scheduled surgery and collect blood, save it for procedure
what are the normal value ranges of : Sodium Potassium Chloride Calcium Phosphate Magnesium Bicarbonate
Sodium : 135- 145 mEq/L Potassium : 3.5-5.0 mEq/L Chloride : 96-106 mEq/L Calcium: 4.5-5.6 mEq/L / (same as 8.6-10.3 mg/dL) Phosphate: 2.4 -4.1 mEq/L Magnesium : 1.5- 2.5 mEq/L Bicarbonate: 22-24 mEq/L
Tetany
a condition characterized by severe muscle cramping (it is associated with depleted calcium levels)
Pt ABG came back with a pH level of 7.29 whats is the result considered? -buffered? -normal? -acidic? -alkaline?
acidic normal range is 7.35-7.45 anything below 7.35 = acidic anything above 7.45= alkaline
a child has been having an asthma attack for the last 8 hrs because of the child's inability to exhale properly he is at risk for respiratory acidosis or alkalosis?
acidosis retained co2 will lead to respiratory acidosis
Average adult fluid intake is :
approx 2200-2700- ml/day ***** oral fluids should be 1100 -1400 ml/day (36-46 oz of water ) = 4.5 cups-6 cups a day
Trousseau's sign
arm/carpal spasm associated with hypocalcemia (B, The Trousseau sign is a carpal spasm induced by inflation of a blood pressure cuff (C) above the systolic pressure for a few minutes.)
Nclex: what to avoid on Low sodium diet
avoid anything processed , ** cereal should be avoided , as it is also processed ketchup the word "can" ex: can of beans most likely indicate high sodium because of the preservatives
Acid-base balance
balance btwn alkaline and acid solution w/ higher # of hydrogens = acid solution w/ low # of hydrogens= alkaline/base The hydrogen (H+) is determined by the ratio of carbonic acid (H2CO3) to bicarbonate (HCO3-) in the extracellular fluid
-bicarbonate/carbonic acid system -respiratory system -renal sytem are the :
buffer systems in the body
poor fluid intake and immobility contribute to__________________
constipation (recommend to ambulate, fiber intake)
Solutions in the body are classified according to the _______________ concentration.
electrolyte (particle)
Adrenosine Triphosphate (ATP)
energy unit in the body
isotonic solution
equal / same concentration as plasma -isotonic solutions expand the body's fluid volume w/out causing fluid shift from one compartment to another (occurs through osmosis)
Hypercalcemia
excessive calcium in the blood causes: -movement of calcium from bone to circulation -immobilization -excess dietary supplement -increased levels of parathyroid hormone SIGNS AND SYMPTOMS: -anorexia, nausea, vomiting -renal calculi -decreased deep tendon reflexes -lethargy, coma -cardiac dysrhythmias -hypertension -decreased muscle tone -decreases GI mobility - bone pain INTERVENTIONS: -administer diuretics are ordered -encourage pt to drink fluids -Monitor I&O
Hyperphosphatemia
excessive phosphate in the blood CAUSE: rare but can result from diet, renal failure SIGNS/SYMPTOMS: -tetany -numbness -tingling TREATMENT: -reducing calcium intake -IV calcium supplement
hyperchloremia
excessive sodium chloride intake -rare, but can happen when bicarbonate levels fall and metabolic acidosis occurs excess chlorine ions would try to compensate
sodium is the major __________ extracellular electrolyte - intracellular? -interstitial? -intravascular? -extracellular?
extracellular
intracellular fluid
fluid inside the cell largest compartment***
extracellular fluid (contains 2 types)
fluid outside the cell. -interstitial fluid: (fluid btwn the cells) ex: lymph, cerebrospinal fluid , GI secretions , urine, perspirations, exudate -intravascular fluid : plasma
hypertonic solution
fluid that is more concentrated than the plasma -hypertonic solutions pull fluid from the cells (occurs through osmosis)
Hypermagnesia
greater values of magnesium in the blood CAUSES: - impaired renal function -diabetic ketoacidosis SIGNS/SYMPTOMS: -cardiac arrest -respiratory depression -hypotension TREATMENT: -decrease pt intake of Ma++ -administer diuretics as ordered
when dealing with potassium always monitor the patient's ________
heart
Electrolytes are measured in milliequivallents: 1 mEq of electrolyte is equal to 1mEq of ______________
hydrogen ex: 1 mEq of potassium =. 1 mEq of hydrogen
Inflitration
leakage of fluid btwn tissues
Women have more body fat than men resulting in
less water in their bodies / less reserve (Fat contains less water in comparison to muscle)
Hypocalcemia
low calcium in the blood CAUSES -alkalosis -anticonvulsants - dietary deficiency -parathyroid hormone (regulates calcium ) -pancreatic disease -crohns dx (is an inflammatory bowel) -celiac dx (immune reaction to gluten -inflammation of the small intestine SIGNS/SYMPTOMS: -cardiac dysrhythmias /cardiac arrest -muscle spasms of the hand and feet -osteoporosis -pathologic fractures (fracture w/out trauma) ex: sneeze and break rib -tetany (trousseau, chvostek sign) -tingling sensation around nose, ears, fingers, toes -twitching INTERVENTIONS: -administer calcium and vit D -monitor EKG , I&O -vitals especially respirations (tetany can cause respiratory arrest)
Hypochloremia
low chloride levels in the blood Causes: associated with sodium loss (vomiting, diarrhea, gastric suctioning ), acute infections symptoms: depressed respirations, tetany , alkalosis treatment: replacing chloride with sodium-chloride iv infusion
Hypophosphatemia
low phosphorus CAUSE: dietary insufficiency or renal failure SIGNS/SYMPTOMS: -muscle weakness -bone and joint pain -disorientation and confusion TREATMENT: -oral or IV supplementation
Nurse is checking lab values on patient with excessive diarrhea pH is 7.10 and the PaCO2 and PaO2 are normal what can the nurse recognize as the pt state?
metabolic acidosis pH is acidic oxygen readings are normal
the most common cause of metabolic _____________ is vomiting gastric contents (acidosis or alkalosis )
metabolic alkalosis
the ___________ are the functioning units of the kidney
nephrons •kidneys plan an important role in fluid balance , they filter blood
Percentage of water in the body by age group:
newborn: 70- 80 % premature baby: 90% (by around 12 yrs old) adult: 50-60 % older adult: 45-55% *** as we age water concentration declines **
Chloride (CL-)
normal blood level 96-106 mEq/L -mainly excreted through the kidneys Function: -bound to another ion usually sodium or potassium -necessary for the formation of hydrochloric acid in gastric secretions -assists in regulation of acid base balance Sources: -foods that contain sodium also contain chloride
Sodium (Na+)
normal blood level is 135-145 mEq/L -mostly found in the extracellular fluid function: regulate's fluid volumes, helps regulate the contractibility of muscular activity (esp in the heart), helps with nerve impulse conduction -water always follows sodium (ex: if sodium stays in the blood , water would make BP go up) mainly excreted: by kidneys sources: salt, canned food, processed , ketchup, chips
Phosphorus
normal levels: 2.4-4.1 mEq/L -mineral substance found in bones in combination with calcium Function: -component of DNA /RNA -essential component for bone -excreted mainly though the kidneys , and feces -phosphorus and calcium compensate for each other -vitamin D needed for absorption -sources: meats, legumes , dairy
Magnesium (Mg++)
normal range: 1.5 - 2.5 mEq/L -excreted mainly through the kidneys Function: -mineral most of it is found in the bones, only small amounts found in the blood -works together to regulate calcium, phosphate, potassium source: widely available no specific source. Whole grains, fruits, green leafy greens, meat, fish, legumes, dairy etc -vitamin B6 regulates how much magnesium is absorbed into the cells
Which set of ABG's values indicates the emphysema (condition in lung that causes SOB) patient is in respiratory acidosis? pH 7.35, Paco2 40, HCO3-22 pH 7.40, Paco2 45, HCO3-30 pH 7.30, Paco2 50, HCO3-24 pH 7.48, Paco2 55, HCO3-18
pH 7.30, Paco2 50, HCO3-24 (Normal ph is 7.35; thus, acidosis is identified. Paco2 greater than 45 is typical of chronic obstructive pulmonary disease)
____________hormone interferes with the absorption and utilization of calcium. Calcium levels below 4.5 mEq/dL can result in tetany and laryngeal spasms that could block the airway.
parathyroid (regulates the serum calcium through its effects on bone, kidney, and intestine)
___________ should be increased during pregnancy and lactation
phosphorus
Patient is told by his doctor to eat more foods rich in potassium. Which fo the following lunch trays would be the best? -seafood salad w/ crackers and strawberries with whipped cream -egg salad on whole grain bread with coffee and potato chips -grilled white toast with tomato soup and orange juice -pork cutlet with milk gravy and mushrooms and melon salad
pork cutlet with milk gravy and mushrooms and melon salad
sodium benzoate
preservative
Homeostasis
process of keeping the fluids in balance
what complication can occur in immobilized patient with hypercalcemia?
renal calculi calcium stored in the bone enters the circulation
pt with vitals of : T 98.6 F P 81 BP 130/86 R 32 which of the following would happen if hyperventilation continues? metabolic acidosis/metabolic alkalosis/respiratory alkalosis/ respiratory acidosis ?
respiratory alkalosis - caused by hyperventilation as the lungs blow off large amount of CO2 some symptoms of resp alkalosis: muscle weakness, tachypnea, cardiac arrythmias,
Signs of fluid overload scenario: pt receiving IV for dehydration suddenly develops a cough and is sob..what should the nurse do?
signs: dyspnea rapid, weak pulse cough disorientation increased or decreased BP crackles pitting edema. the nurse should auscultate the lungs and asses for fluid overload, slow the infusion, and notify the RN
induration
solid enlargement • when we test for tb we test for solid enlargement (induration)
hypotonic solution
solution that is less concentrated than the plasma -hypotonic solutions move into the cells, causing them to enlarge (occurs through osmosis)
Nclex: what should you feed hypotensive patient?
something salty ex: saltine crackers
interstitial
space btwn the cells
glomerular filtration rate
the flow rate of filtered fluid through the kidney • output of 1 to 2 L (1,000 - 2,000 ml) of urine per day
The primary excretion routes for the electrolytes sodium and potassium are:
the kidneys (The kidneys are the primary route of excretion and affect how much is retained and how much is excreted.)
hydrostatic pressure
transporting electrolytes from area of high concentration to low concentration (happens during filtration- which is a form of active transport)
_____________ the largest component of the body
water
How to determine water balance?
weight the patient daily under the same conditions ex: same amount of clothes, attached to same equipment, same time of day etc. (1L=1kg=2.2 lbs)
Thirst receptors
• hypothalamus : osmoreceptors = sensation of thirst •unable to perceive or respond to thirst mechanism = risk for dehydration • pt may require tube feedings, total parenteral nutrition (TPN) aka "IV infusion"
Urine Specific Gravity
• measurement of urine concentration more than 1.030 = concentrated less than 1.003-1.000 = dilute (ex: dehydration)
Dehydration and older adults factors :
•aging kidney is less able to concentrate urine, so more fluid is lost (urine is more diluted) •decreased in mobility •decreased sense of thirst intervention = establish drinking habits, measure in/output •incontinence - some older adults reduce their fluid intake so they don't have to use the restroom that much •changes in tase - adults add more salt to their food resulting in electrolyte imbalances. Intervention = recommend salt free seasoning
Signs and symptoms of dehydration:
•thirst •dry mucous membranes •increased heart rate •decreased blood pressure •poor skin turgor •flat neck veins • orthostatic hypotension = risk for falls •kidney slows down = becomes less effective at excretion = higher risk of electrolyte imbalance