Fluid & Electrolytes (exam4)
Thiazides and Thiazide-Like Diuretics
• Class: Sulfonamides • Potassium Wasting • 1st line drug to manage HTN • Block chloride pump • Prototype: Hydrochlorothiazide (HCTZ) • Adverse effects: GI upset, fluid and electrolyte imbalance, hypotension, CNS depression, uric acid buildup, hypokalemia, hypercalcemia, increase in blood glucose, increase frequency in bladder infections • Cautions: Crosses the placenta and enters breast milk, allergies to thiazides and sulfonamides, Carefully use in patients with lupus, liver disease, DM, hyper-parathyroid, bipolar disorder & gout, use carefully with digoxin
What causes edema?
• Sodium retention, burns, infection, corticosteroids, NSAIDs, Anti-HTN, estrogen use.
Hypertonic 3% NS
• Used to decrease intracellular swelling, increases ECF • Treats severe, symptomatic hyponatremia or cerebral edema
Trousseau sign
is elicited when the brachial artery is compressed. Inflate BP cuff for 3 mins and hand will contract upwards. Sign of tetany
Chvostek's sign
is elicited when you tap on the face at the trigeminal facial nerve. Causes nerve spasm and lip, nose or face will crunch up or lift toward the ear
Hypovolemia Medical Management:
Encourage oral intake, IV solutions (NS, LR) when hypotensive. Once normotensive (0.45% NS)
What does water do for the body?
Transports nutrients and waste Transports hormones, enzymes, RBCs, WBCs, platelets Solvent for electrolytes Helps maintain body temperature Facilitates cell metabolism, digestion, and elimination Acts as a tissue lubricant
Managing hypokalemia
increased dietary potassium, potassium replacement (if liquid dilute the taste by mixing with juice), IV for severe deficit Nursing management: assessment, severe hypokalemia is life-threatening, monitor ECG and ABGs, dietary potassium, nursing care related to IV potassium administration Caution: Cannot ever replace potassium by IVP!
managing hyperkalemia
monitor ECG, limitation of dietary potassium, cation-exchange resin (Kayexalate), IV sodium bicarbonate, IV calcium gluconate, regular insulin and hypertonic dextrose IV, Beta-2 agonists, dialysis • Nursing management: assessment of serum potassium levels, VS, ECG, f/u lab values, educate on proper diet/restriction Caution: Hemolysis of blood specimen or drawing of blood above IV site may result in false laboratory result, salt substitutes, medications may contain potassium and potassiumsparing diuretics may cause elevation of potassium(Do not use with renal patients)
Major cations:
sodium, potassium, calcium, magnesium, hydrogen ions
Third Spacing
Fluid shift into transcellular compartments Examples: ascites, pleural effusion, pericardial effusion, and angioedema Causes: Bowel obstruction, severe burns, cirrhosis, injury/trauma, surgical procedures, heart failure, decrease in albumin, sepsis Signs & Symptoms: Decreased UOP with adequate intake, increased heart rate, decreased blood pressure, pitting edema, ascites Management: Paracentesis, pericardiocentesis,replacement fluids, albumin
Loop Diuretics
High-ceiling diuretic Prototype: Furosemide Block chloride pump in the ascending loop of Henle Commonly indicated for acute HF, acute pulmonary edema, HTN, edema of liver, heart, and renal disease Adverse effects: hypokalemia, hypocalcemia, hypotension, dizziness, ototoxicity, CNS depression, GI upset, hyperglycemia Caution: Anticoagulation, NSAIDS, Aminoglycosides
What pathology is responsible for metabolic acidosis? A. An increase of CO2 B. An excess of HCO3 and/or a decrease in H+ ions C. A decrease in bicarbonate or an increase in hydrogen ions D. A decrease of carbonic acid
C
Intravascular space
(the fluid within the blood vessels) contains plasma, the effective circulating volume. Approximately 3 L of the average 6 L of blood volume in adults is made up of plasma. The remaining 3 L is made up of the blood cells: erythrocytes, leukocytes, and thrombocytes (platelets).
Magnesium
1.8-2.6 - One third is bound to protein -Required for carbohydrate and protein metabolism -Balance is important in neuromuscular function -Produces sedative effect by inhibiting acetylcholine -Affects the cardiovascular system, acting peripherally to produce dilation and decrease peripheral resistance
Mag++ levels
1.8-2.6 mg/dL
K+ value
3.5-5.0 mEq/L
hypotonic solution
: a solution with an osmolality lower than that of serum • 0.45% NS • 0.33% NS • 0.2% NS • 2.5% Dextrose water
Potassium Rich Foods
Avocados Dried fruits Navy Beans Prunes Sunflower seeds Bananas Broccoli Lima beans Oranges Peaches Peppers Rhubarb Tomatoes Cantaloupe Nuts Grapefruit Spinach Potatoes Coffee Watermelon
D5W
Contains 50g dextrose, no electrolytes. Aids renal excretion Treats: hypernatremia, fluid loss and dehydration Do not use postop, head injury, fluid resuscitation or in infants
Normal Saline (NS)
Description: 0.9% NaCl in Water Crystalloid Solution {An isotonic crystalloid solution that contains sodium chloride (salt) as the solute, dissolved in sterile water (solvent). The specific concentration for normal saline solution is 0.9%.} Osmolality: Isotonic Use: Increases circulating plasma volume when red cells are adequate Hypovolemia, shock, DKA, resuscitation (#1) Metabolic alkalosis, hypercalcemia, hyponatremia Caution with decreased renal function, HF & edema
Hypervolemia S/S
Edema, JVD, crackles, weight gain, SOB, cough, bounding pulses, increased BP/urine output, S3 heart sound
Hypovolemia Diagnostics
Increased urine osmolality, specific gravity, BUN, H/H, decreased urine Na+
Hypercalcemia causes
Malignancy, hyperparathyroidism, prolonged immobilization, thiazides, corticosteroids, acidosis, vitamin D excess, overuse of calcium supplements
Considerations in daily weights
Patients on diuretic therapy should weigh daily-same clothes, same scale, same time of day
Hypomagnesemia causes
alcoholism, malabsorption, diarrhea, parenteral nutrition, diabetic ketoacidosis
Hypovolemia
decreased blood volume
The thirst center is located in the
hypothalamus
Clinical Manifestations: Hyponatremia
poor skin turgor, dry mucosa, headache, decreased salivation, decreased blood pressure, nausea, abdominal cramping, neurologic changes
insensible water loss
the loss of water not noticeable by a person, such as through evaporation from the skin and exhalation from the lungs during breathing
Sensible losses are:
urine and feces
A nurse is caring for a client who has a serum potassium level of 5.4 mEq/L. The nurse should assess for which of the following manifestations? A. ECG changes B. Constipation C. Polyuria D. Paresthesia
A
Nursing Management: Hypervolemia
Closely monitor I&Os, daily weight, assess heart and lung sounds, monitor edema, elevate legs
Hypervolemia Diagnostics
Decreased H/H, BUN, serum and urine osmolality, urine sodium and specific gravity. Chest x-ray may reveal pulmonary congestion
what causes hypervolemia?
Heart, renal, or liver failure Consumption of excessive amounts of table or sodium salts. Excessive administration of sodium containing fluids in impaired regulatory mechanisms
major anions
chloride, bicarbonate, phosphate, sulfate, proteinate ions
Osmosis
the process by which fluid moves across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration; the process continues until the solute concentrations are equal on both sides of the membrane
The transcellular space
the smallest division of the ECF compartment and contains approximately 1 L. Examples of transcellular fluids include cerebrospinal, pericardial, synovial, intraocular, and pleural fluids, sweat, and digestive secretions.
Clinical manifestations of hypernatremia
thirst (may be impaired in elderly patients); elevated temperature; dry, swollen tongue; sticky mucosa; neurologic symptoms; restlessness; weakness
Hypotonic 0.45% NS
• Helps kidneys eliminate wastes, treats dehydration d/t DKA • Not used in third-space shifts, increased ICP, liver disease, trauma or burns
Na+ normal value
135-145 mEq/L
Serum calcium levels
8.8-10.4
What causes hypokalemia?
: Inadequate intake, diuretic and insulin therapy, trauma, stress, laxative abuse, metabolic alkalosis, vomiting, diarrhea, gastric suction, low magnesium
Hypercalcemia S/S
: Muscular weakness, ataxia, constipation, N/V, polyuria, polydipsia, dehydration, pathologic fractures, deep bone pain, renal stones, lethargy, cardiovascular changes
hypertonic solution
: a solution with an osmolality higher than that of serum • 3% NS • 5% NS • D5 + 0.9% NS • D5 + LR • D10W
When assessing a patient's altered fluid status, the nurse expects to assess/review which of the following? (Select all that apply.) A. Vital signs and skin turgor b. Hematocrit and electrolytes C. Fluid intake and urine output D. Capillary refill and mucous membranes
A,B.C.D
A client has a respiratory rate of 38 breaths/min. What effect does breathing faster have on arterial pH level? A. No effect B. Increases arterial pH C. Provides long-term pH regulation D. Decreases arterial pH
B
A nurse is providing client teaching about the body's plasma pH and the client asks the nurse what is the major chemical regulator of plasma pH. What is the best response by the nurse? A. renin-angiotensin-aldosterone system B. bicarbonate-carbonic acid buffer system C. sodium-potassium pump D. ADH-ANP buffer system
B
Hypokalemia is confirmed by what serum blood result? A. Sodium 133 mEq/L B. Potassium 3.0 mEq/L C. Potassium 5.5 mEq/L D. Sodium 146 mEq/L
B
Hyponatremia is associated with a decrease of which electrolyte? A. Phosphorus B. Potassium C. Sodium D. Chloride
C
Hypovolemia causes
Decreased intake, vomiting, diarrhea, GI suctioning, excessive diuresis, or sweating
managing hypercalcemia
IV NS, IV phosphate, calcitonin, corticosteroids Nursing Management: assessment, hypercalcemic crisis has high mortality, encourage ambulation, fluids of 3 to 4 L/d, provide fluids containing sodium unless contraindicated, fiber for constipation, ensure safety, monitor for digoxin toxicity
Hypocalcemia treatment
Oral intake of calcium & vitamin D, Ca+ chloride or gluconate, mixed in D5W, never in NS, educate on Ca+ rich diet, avoid giving calcium to patients on digoxin, alcohol and caffeine inhibit absorption
Hypovolemia S/S
Thirst, oliguria, decreased skin turgor, sunken eyes, weak/thready pulse, hypotension, tachycardia, increased cap refill, dry mucosa, depressed fontanels
colloid:
a fluid containing particles that are nonsoluble and evenly distributed throughout the solution
crystalloid:
a fluid containing soluble mineral ions and water in solution
The interstitial space
contains the fluid that surrounds the cell and totals about 11 to 12 L in an adult. Lymph is an interstitial fluid.
Hypernatremia
high sodium Hypertonic environment where there is an increase of Na+ and/or a loss of water Most often impacts patients who are elderly, very young or cognitively impaired.
Sodium
135-145 mEq/L The most abundant electrolyte in ECF Primary determinant of ECF volume and osmolality Regulated by ADH, thirst, and renin-angiotensin-aldosterone system Loss or gain accompanied by loss or gain of water
Potassium
3.5-5.0 mEq/L Renal system must function to maintain balance Kidneys continuously excrete even in a deficit Potassium conducts nerve impulses and controls the excitability of skeletal, cardiac and smooth muscles.
Calcium
8.8-10.4 Types of calcium: • Serum and ionized calcium • Ionized Ca+ 4.5-5.1 • Ionized Ca+ is the only form free to engage in cellular activity • Serum calcium is largely bound to albumin Roles • 99% located in skeletal system • Transmits nerves impulses and regulates muscle contraction and relaxation • Essential for coagulation
Chloride levels (Cl-)
97-107
Early signs of hypervolemia include A. a decrease in blood pressure. B. increased breathing effort and weight gain. C. moist breath sounds. D. thirst.
B
A nurse is reviewing a report of a client's routine urinalysis. Which value requires further investigation? A. Absence of glucose B. Specific gravity of 1.02 C. Urine pH of 3.0 D. Absence of protein
C
A nurse reviews the results of an electrocardiogram (ECG) for a patient who is being assessed for hypokalemia. Which of the following would the nurse notice as the most significant diagnostic indicator? A. Peaked T wave b. Widened QRS wave C. Elevated U wave D. Flat P wave
C
A client experiencing a severe anxiety attack and hyperventilating presents to the emergency department. The nurse would expect the client's pH value to be A. 7.45 B. 7.35 C. 7.50 D. 7.30
C
Manifestations of hyperkalemia?
Muscle weakness, arrhythmias, flaccid paralysis, paresthesias, abdominal distention, ECG changes
• Which assessment findings indicates fluid volume excess relate to a client's IV fluids infusing at 150mL/hr. SELECT ALL THAT APPLY. A. Neck veins distended when HOB elevated to 45 degrees B. Hand veins empty when hand is raised above the heart C. Peripheral pulses are rapid and bounding D. Client becomes SOB with ambulation only E. Pitting edema is present over the tibia
A,C,E
Carbonic Anhydrase Inhibitors
• Mild diuretics • Prototype: Acetazolamide • Used to treat glaucoma, HF, epilepsy, mountain sickness • Actions: Inhibits carbonic anhydrase, which decreases aqueous humor formation in the eye, IOP, and hydrogen secretions by the renal tubules • Side effects: GI upset, urinary frequency, fatigue, rash, bone marrow suppression • Metabolic acidosis, hypokalemia, paresthesia, confusion, drowsiness • Cautions • Don't give if allergic to thiazides or sulfonamides drugs • Do not give during pregnancy or nursing d/t fetal abnormalities • Na+ and Bicarb are lost in urine—use extreme caution in an acidotic environment
Diuretics in pediatrics
Used to treat edema associated with heart defects, renal & pulmonary disorders & HTN • Hydrochlorothiazide & chlorothiazide, Furosemide, Spironolactone • Effects of diuretic may be rapid with adverse effects happening suddenly. • Monitor for S/S electrolyte & fluid volume imbalances, ototoxicity
Hypocalcemia S/S
tetany, paresthesias, hyperactive DTRs, anxiety, seizures, laryngeal spasms, hypotension, confusion, hallucinations, Chvostek sign, Trousseau sign
isotonic solution
: a solution with the same osmolality as blood • 0.9% NS • Lactated Ringers • Plasma - Lyte • D5W
What causes hyponatremia?
: adrenal insufficiency, renal disease, excessive administration of D5W, SIADH, or losses by vomiting, diarrhea, sweating, diuretics
When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis? A. O2 saturation 95% B. pH 7.48 C. PaCO 36 D. HCO 21 mEq/L
B
Homeostasis
Constant internal equilibrium in a biological system using positive and negative feedback mechanisms Homeostasis is threated by ANY illness, individual behaviors, and our environment Without this consistent balance, your body will be unable to effectively maintain its regular function
Managing Hypernatremia
hypotonic electrolyte solution or D5W Nursing management: assessment and prevention, assess for OTC sources of sodium, offer andencourage fluids to meet patient needs, provide sufficient water with tube feedings
Lactated Ringers
Contains electrolytes. Treats burns (#1), acute blood loss Lactate metabolizes in bicarb: do not use in lactic acidosis Do not use with pH >7.5 or in kidney injury
Nursing Management: Hypovolemia
Monitor I&Os, daily weight, VS, mental status, turgor, oral care, volume of IV fluids Identify clients at risk and take measures to minimize fluid losses Gerontologic consideration
Hypomagnesemia S/S
: hyperactive DTRs, insomnia, mood changes, ataxia, vertigo, ECG changes and dysrhythmias
A nursing instructor is teaching her class about burns. The instructor relates the following scenario: A nurse is caring for a severely burned client who now has elevated hematocrit and blood cell counts. What consequences should the nurse expect in this client? A. Imbalance in electrolytes B. Kidney stones and blood clots C. Elevated central venous pressure (CVP) D. Slow heart rate
B
Clinical manifestations of hypokalemia?
Muscle weakness, leg cramps, fatigue, paresthesias, abdominal distention, hypoactive reflexes, dysrhythmias, ECG changes
Medical Management: Hypervolemia
: If related to fluid administration discontinue the infusion, Na+ and water restriction, diuretics, replace electrolyte imbalances, dialysis, salt substitutes
What causes hyperkalemia?
: decreased renal elimination, rapid administration of potassium, movement from ICF to ECF, metabolic acidosis , Addisons, crush injury, medications & blood transfusions
Hypernatremia causes
: enteralfeedings, diarrhea, hyperventilation, burns, diabetes insipidus
The nurse is completing the physician's orders by preparing the patient's IV fluid therapy. When infusing supplemental potassium, the nurse knows that checking which of the following is the first priority before beginning the infusion? A. Potassium level B. Urine output C. Infusion device D. Tubing date
A
Which of the following concerning the measurement of intake and output is true for a patient admitted for dehydration? A. Liquid medications are not considered when calculating intake. B. When possible, intake and output should be measured rather than estimated. C. Only foods that are consumed as liquids are included in intake calculations. D. Health care agencies have adopted standard volumes for common beverage containers.
B
The nurse is caring for four clients on a medical unit. The nurse is most correct to review which client's laboratory reports first for an electrolyte imbalance? A. A 72-year-old with a total knee repair B. A 65-year-old with a myocardial infarction C. A 52-year-old with diarrhea D. A 7-year-old with a fracture tibia
C
What determines the acidity of substances such as body fluids? A. The fluid's pH measurement B. The amount of available HCO3 C. The number of existing H+ ions D. The body's ability to trigger chemical reactions
C
Active transport
Energy-requiring process that moves material across a cell membrane against a concentration difference
Natriuretic Peptides
Hormones that affect fluid volume and cardiovascular function Natriuresis, direct vasodilation, and the opposition of the reninangiotensin-aldosterone system Most common are atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), N-terminal fragment of pro-brain natriuretic peptide (NT-pro BNP)
managing hyponatremia
LR and NS for those who can't consume sodium Serum sodium must not be increased by more than 12 mEq/L per 24 hrs SIADH: hypertonic IV solution (SLOWLY) with the addition of diuretics such as furosemide Nursing: assessment and prevention, dietary sodium and fluid intake, identify and monitor at-risk patients, effects of medications (diuretics, lithium)
Who has the most water in their body?
Men and young adults typically have higher water content
Diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration.
Gerontologic Considerations
Normal physiologic changes may alter the older adult's responses to fluid and electrolyte changes and acid-base disturbances • Decreased respiratory function and renal function can cause impaired acid-base balance in older adults with major illness or trauma. • Decreased renal function that occurs with age can also cause slightly elevated serum creatinine. • Decreased muscle mass that occurs with aging leads to decreased daily breakdown of muscle, which reduces serum creatinine.
Potassium Sparing Diuretics
Not as powerful as loop diuretics, but retain potassium Prototype: Spironolactone Often used in conjunction with thiazide or loop diuretics, especially in patients at risk of hypokalemia Adverse effects: Hyperkalemia (lethargy, confusion, ataxia, arrhythmias), CNS effects, diarrhea, hirsutism, gynecomastia, voice deepening, irregular menses
Osmotic Diuretics
Pull water into the renal tubule without sodium loss Prototype: Mannitol Indications: reduces ICP &IOP, acute renal failure related shock drug overdose, trauma Adverse effects: sudden drop in fluid volume, nausea, vomiting, hypotension, light-headedness, confusion, headache, cardiac decompensation, shock Contraindicated in renal disease and anuria from severe renal disease, pulmonary congestion, intracranial bleeding, dehydration, HF. Routine use in pregnancy not appropriate
intake
the amount of fluid taken in • Ingestion of liquids provides largest amount • Water contained in foods • Byproduct of metabolism • Averages about 2500 ml/day
Hypervolemia
abnormal increase in the volume of blood plasma in the body Expansion of ECF caused by abnormal retention of water and Na+ in approximately the same proportions in which they normal exist in ECF
Hypocalcemia causes
deficient calcium in the blood hypoparathyroidism, malabsorption, pancreatitis, alkalosis, massive blood transfusion, renal failure, medications, bed bound, vitamin D deficiency
