NUR240 Ch. 13 Concepts of Fluid & Electrolyte Balance

Which statement describes isotonic dehydration?

*** A: Fluids and electrolytes are lost from the body in equal amounts. B: Electrolytes are lost from the body in greater quantities than fluids. C: Fluids are lost from the body in greater quantities than electrolytes. D: Fluids and electrolytes are lost from the body, but only water is replaced. Rationale: Isotonic dehydration is when fluids and electrolytes are lost in equal quantities. Hypertonic dehydration occurs when fluids are lost in greater quantities than electrolytes. Hypotonic dehydration occurs when electrolytes are lost in greater quantities than fluids, or when fluid and electrolyte losses are replaced by water only.

Which electrolyte imbalance would the nurse anticipate for a patient who is admitted with fluid volume overload? Select all that apply. One, some, or all responses may be correct.

*** A: Hypokalemia *** B: Hyponatremia C: Hypercalcemia *** D: Hypochloremia E: Hypermagnesemia

A patient has a low serum potassium level and is prescribed a dose of parenteral potassium chloride (KCl). Which administration method would the nurse use?

*** A: Infuse 10 mEq over a 1-hour period. B: Administer 5 mEq IM. C: Push 5 mEq through a central access line. D: Dilute 200 mEq in 1 L of normal saline, and infuse at 100 mL/hr.

Which condition may contribute to a patient's insensible water loss? Select all that apply. One, some, or all responses may be correct.

*** A: Severe diarrhea *** B: Respiratory rate of 36 breaths/min *** C: Hot, dry home environment D: Body temperature of 96.4°F (36°C) E: Large volume of urinary output

Which electrolyte deficiency results in reduced excitable membrane depolarization and increased cellular swelling?

*** A: Sodium B: Calcium C: Potassium D: Magnesium Rationale: Hyponatremia occurs when sodium levels are low; this condition causes decreased depolarization in excitable cells and increased cellular swelling. Low serum calcium levels lead to muscle cramping and cardiac arrhythmias. A potassium deficiency causes cardiac dysrhythmias. A decrease in the level of magnesium may cause increased nerve impulse transmission.

The nurse is admitting a 78-year-old patient with severe diarrhea. Which assessment finding indicates that the patient may be dehydrated? Select all that apply. One, some, or all responses may be correct.

A: Distended neck veins B: Bounding radial pulses *** C: Temperature of 99.4°F (37.4°C) *** D: Dizziness when standing *** E: Newly reported confusion Rationale: Postural hypotension causing dizziness may occur with dehydration. Because of decreased perfusion to the brain, confusion is common in older adults. Low-grade fever is a common result of dehydration. With dehydration, neck veins are flat, not distended; peripheral pulses are weak, not bounding.

Which item will the nurse include when documenting a patient's fluid intake? Select all that apply. One, some, or all responses may be correct.

A: Emesis *** B: Enemas *** C: Oral fluids D: Solid foods *** E: Irrigation fluids

Which cardiovascular change would the nurse expect to find in a patient with fluid overload?

A: Flat jugular veins *** B: Increased heart rate C: Widened pulse pressure D: Decreased blood pressure

Which laboratory test would demonstrate effectiveness of diuretic therapy for a patient admitted with fluid overload from heart failure?

A: Serum osmolality B: Serum creatinine *** C: Natriuretic peptide D: Serum magnesium

When a patient reports disturbed deep sleep because of frequent cramping in the calves, which electrolyte would the nurse review in the patient's health record?

A: Sodium *** B: Calcium C: Potassium D: Magnesium Rationale: Low calcium levels can cause muscle spasms, or charley horses, in the thigh, calf, or foot while sleeping. Sodium loss can cause neurologic changes such as seizures. Potassium and magnesium losses can lead to cardiac dysrhythmias.

After administering IV magnesium sulfate (MgSO4) to a patient with hypomagnesemia, which assessment would the nurse perform to determine the effectiveness of the medication?

A: Urinary output B: Peripheral pulses *** C: Deep tendon reflexes D: Serum albumin levels Rationale: Patients with hypomagnesemia will have hyperactive deep tendon reflexes. Hypermagnesemia levels will result in reduced or absent deep tendon reflexes. The nurse should monitor the medication's effectiveness by assessing deep tendon reflexes. Urinary output will be monitored in patients with fluid and sodium imbalances. If the patient has fluid overload, the nurse should monitor peripheral pulses. Low serum albumin levels can increase fluid retention in the extravascular spaces (edema).

A patient's temperature has risen 2°C from normal. Calculate the amount of body fluid the patient has lost. Record your answer using a whole number. _________ mL

*** 1,000 mL Rationale: When a patient's temperature is above normal (98.6°F [37°C]), the body will lose 500 mL for every degree Celsius the temperature has risen. Therefore a patient with a temperature 2°C over normal would have lost 1000 mL of body fluid.

For the patient with increased fluid volume secondary to heart failure, which intervention would the nurse include in the patient's plan of care? Select all that apply. One, some, or all responses may be correct.

*** A: Daily weights *** B: Skin pressure relief *** C: Fluid restriction *** D: Diuretic therapy *** E: Low-sodium diet Rationale: Interventions the nurse should include in the patient's plan of care to decrease fluid volume are weighing the patient daily to assess fluid volume; implementing skin pressure-relieving measures as the patient is at increased risk for skin breakdown because of edema; providing instructions regarding fluid restriction and a low-sodium diet to decrease fluid volume; and administering diuretics to eliminate excess fluid.

Which assessment finding indicates that a patient is dehydrated? Select all that apply. One, some, or all responses may be correct.

*** A: Fever B: Hypertension *** C: Poor skin turgor D: Pulmonary crackles *** E: Low blood pressure *** F: Concentrated urine

Which electrolyte excess results in cellular irritability and severe cellular dehydration?

*** A: Sodium B: Calcium C: Phosphorus D: Magnesium Rationale: Hypernatremia occurs when serum sodium levels are very high; this condition causes excitable tissues to overrespond to stimuli. This leads to irritability and severe cellular dehydration. Hypercalcemia, an excess of calcium, decreases the sensitivity of excitable tissues to normal stimuli. Hyperphosphatemia (excess phosphorus) causes hypocalcemia. Hypermagnesemia (excess magnesium) causes hypotension, bradycardia, central nervous system changes, and neuromuscular changes.

When concerned about a patient's GI fluid losses, which parameter would the nurse assess to determine fluid loss? Select all that apply. One, some, or all responses may be correct.

*** A: Weight *** B: Skin turgor *** C: Urine output *** D: Blood pressure *** E: Blood urea nitrogen (BUN) Rationale: One lb of water weighs about 2.2 lb (1 kg). Therefore the nurse should monitor the patient's weight. The nurse should assess the patient's skin turgor as loss of elasticity can occur from dehydration. Diminished urine output could indicate fluid balance changes. The nurse should also monitor the patient's blood pressure for hypotension from low fluid volume. The BUN would increase with dehydration, so the nurse should also assess this laboratory value.

An older adult admitted with dehydration and a history of stress incontinence expresses embarrassment about the need for absorbent undergarments. Which question would the nurse ask this patient related to the present illness?

A: "How is your appetite?" B: "Have you noticed a change in the tightness of your shoes?" C: "What is your typical urinary elimination pattern and amount?" *** D: "What is your typical amount and type of daily fluid intake?"

Which statement by a patient with congestive heart failure indicates a correct understanding of self-monitoring?

A: "I can gain 2 lb of water each day without concern." B: "I should call my provider if I gain more than 1 lb a week." *** C: "Weighing myself daily can reveal increased fluid retention." D: "Weighing myself daily can determine if my caloric intake is adequate." Rationale: Fluid retention may not be visible. Rapid weight gain is the best indicator of fluid retention and overload. Each pound of weight gained (after the first half-pound) equates to 500 mL of retained water. The patient should be weighed at the same time every day (before breakfast) on the same scale. Daily weights are not an indication of effective dieting for purposes of weight loss or gain. They will show fluid retention after an especially high sodium intake (in a patient with fluid retention problems), but caloric intake is related to food intake rather than fluid retention problems. The patient should call the health care provider if more than 1 or 2 lb are gained in a 24-hour period of if more than 3 lb are gained in 1 week.

Which information would the nurse include when teaching a patient about maintaining fluid balance?

A: "If you increase your intake of salt, you are at a greater risk for dehydration." *** B: "Your intake and output have the most influence on your body's fluid balance." C: "If you decrease your intake of potassium, you are at greater risk for dehydration." D: "Your prescribed medications have the largest impact on fluid balance in the body."

What statement by the student nurse indicates a need for further teaching about how healthy adults can prevent mild dehydration?

A: "Include drinking lots of water in dry climates." B: "Refrain from any beverages containing alcohol." *** C: "Consume more beverages that contain caffeine." D: "Drink lots of water after prolonged physical activity."

A patient with pitting edema of the right foot and ankle is prescribed diuretic therapy. Which intervention would the nurse include in the plan of care? Select all that apply. One, some, or all responses may be correct.

A: Monitoring respiratory rate *** B: Monitoring urine output *** C: Assessing sodium and potassium values D: Checking urine for specific gravity *** E: Monitoring ECG patterns Rationale: Patients with fluid overload often have pitting edema, and diuretic therapy focuses on removing the excess fluid. The nursing interventions would be monitoring the patient's response to drug therapy, especially increased urine output and weight loss. Diuretic therapy is associated with electrolyte imbalance; therefore sodium and potassium levels need to be monitored. Severe electrolyte disturbances may result in arrhythmias. Therefore changes in the ECG should be monitored.

For a patient who presents with hypokalemia secondary to loop diuretic use, which food would the nurse teach the patient to eat? Select all that apply. One, some, or all responses may be correct.

A: Pasta B: Apples *** C: Bananas D: Cauliflower E: Blackberries Rationale: Bananas, oranges, and grapes are high in potassium and should be included in the diet when a patient is taking diuretics that cause potassium loss.

Which electrolyte imbalance should be anticipated in a patient with hyperphosphatemia?

A: Hypokalemia *** B: Hypocalcemia C: Hypernatremia D: Hypermagnesemia Rationale: Phosphorus and calcium have an inverse or reciprocal relationship. When one is increased, the other is usually decreased. Therefore a patient with hyperphosphatemia should be monitored for hypocalcemia. Hyperphosphatemia does not cause hypernatremia, hypokalemia, or hypermagnesemia.

Which daily dietary sodium limit would the nurse suggest for the patient with chronic fluid overload?

*** A: 2 to 3 g B: 4 to 5 g C: 5 to 6 g D: 6 to 7 g Rationale: Excessive sodium and fluid intake are the main causes of hypervolemia or fluid overload. Nutrition therapy for the patient with fluid overload may involve restriction of sodium and fluid intake. A patient experiencing chronic fluid overload may be restricted to 2 to 3 g/day of sodium. Intake of more than 4 g/day of sodium may lead to further fluid overload and retention.

Which factor affects the amount and distribution of body fluids? Select all that apply. One, some, or all responses may be correct.

*** A: Age B: Poverty C: Activity *** D: Sex *** E: Body fat F: Cognition

Which finding would the nurse expect during the assessment of a patient with a serum potassium level of 6.8 mEq/L? Select all that apply. One, some, or all responses may be correct.

*** A: Bradycardia *** B: Muscle twitching *** C: Extremity numbness *** D: Cardiac dysrhythmias *** E: Hyperactive bowel sounds Rationale: With a potassium level of 6.8 mEq/L, this patient has hyperkalemia, a condition that can cause multiple clinical manifestations including bradycardia, muscle twitching and numbness of the hands and feet, cardiac dysrhythmias, and hyperactive bowel sounds.

Which serum electrolyte result would be of concern to the nurse?

*** A: Chloride: 88 mEq/L B: Sodium: 143 mEq/L C: Potassium: 4.8 mEq/L D: Magnesium: 2.0 mEq/L Rationale: he chloride level of 88 mEq/L is low, so it would be concerning to the nurse. The normal chloride range is 98 to 106 mEq/L. A decreased range is indicative of fluid loss that may be the result of dehydration, vomiting, or diarrhea. The sodium, magnesium, and potassium levels are within the normal ranges.

Which finding would the nurse expect to notice during an assessment of a patient admitted with hypocalcemia secondary to chronic kidney disease?

*** A: Circumoral tingling B: Lethargy and seizures D: Negative Trousseau sign E: Hypoactive bowel sounds Rationale: A patient with hypocalcemia secondary to chronic kidney disease may notice tingling of the nose, lips, and ears as this precedes tetany. Lethargy and seizures occur from hyponatremia. A positive Trousseau sign and hyperactive bowel sounds are all signs of hypocalcemia.

Which assessment of a patient's mucous membranes would the nurse use to evaluate the patient for dehydration? Select all that apply. One, some, or all responses may be correct.

*** A: Color B: Pulse *** C: Turgor *** D: Moisture E: Temperature

A patient has dry skin, a heart rate of 115 beats/min, a respiratory rate of 28 breaths/min, and weight loss of 1 lb in 1 day. Which condition would the nurse suspect?

*** A: Dehydration B: Hyperkalemia C: Fluid overload D: Hyponatremia Rationale: The best indicator of fluid loss or fluid overload is daily weight. Decrease in weight may occur because of fluid losses, which may affect the cardiovascular system. Therefore the heart rate increases in an attempt to maintain blood pressure when the blood volume decreases. Dehydration decreases the blood volume, which may result in an increased respiratory rate. Dry skin also indicates dehydration. Hyperkalemia causes cardiovascular effects such as bradycardia, hypotension, and arrhythmias. Fluid overload causes edema and an increase in weight. Hyponatremia causes cerebral changes such as cerebral edema and increased intracranial pressure.

Which parameter would the nurse monitor to assess a patient's response to fluid replacement therapy? Select all that apply. One, some, or all responses may be correct.

*** A: Monitoring pulse quality *** B: Monitoring urine output C: Monitoring serum bilirubin D: Monitoring white blood cell count *** E: Monitoring weight change

Which finding would indicate that a patient admitted with fluid overload may have been overdiuresed? Select all that apply. One, some, or all responses may be correct.

*** A: Report of fatigue *** B: Weight loss of 9 lb *** C: Heart rate increase from 70 to 96 beats/min D: Heart rate decrease from 80 to 72 beats/min E: Respiratory rate decrease from 20 to 16 breaths/min *** F: Report of light-headedness when first standing up Rationale: Diuretic drugs cause water loss and are often prescribed for edema. Since 1 L of water weighs 2.2 lb, weight loss is expected when the patient gets rid of excess water. If the prescribed diuretic is overly effective, too much water may be excreted by the kidneys, and signs of dehydration from overdiuresis may occur. A weight loss of 9 lb is approximately 4 L of fluid. Light-headedness when changing positions may suggest orthostatic hypotension. Other signs of too much fluid loss include an increase in heart rate and fatigue. The decrease in heart rate and respiratory rate would suggest the diuretic was effective.

An older adult is brought into the emergency department with persistent vomiting and diarrhea. The caregiver states that the patient has lost 4 lb since the symptoms began. Approximately how much fluid has the patient lost?

A: 500 mL B: 1 L C: 1.5 L *** D: 2 L Rationale: One pound of body weight is approximately equal to 500 mL of fluid. With a weight change of 4 lb, the child has lost approximately 2 L of fluid.

Which patient on a medical-surgical unit is at an increased risk for insensible water loss?

A: A patient receiving humidified oxygen by nasal cannula *** B: A patient receiving continuous GI suctioning postoperatively C: A patient with decreased respirations because of opioid administration for pain D: A patient receiving continuous IV fluids after surgery

Which ECG finding is consistent with hyperkalemia?

A: Absent T waves B: Elevated P waves *** C: Prolonged PR intervals D: Shortened QRS complexes

For a patient prescribed furosemide as part of treatment plan for cirrhosis and excess fluid volume, which patient goal would the nurse establish for this patient?

A: Adds salt in diet *** B: 10-lb weight loss C: Potassium level 3.0 mEq/L D: Intake greater than output

Which hormone regulates fluid and electrolyte balance by preventing water and sodium loss?

A: Antidiuretic B: Thyrotropin *** C: Aldosterone D: Natriuretic peptide (NP) Rationale: Aldosterone stimulates the nephrons to reabsorb sodium and water into the blood, preventing sodium and water loss. NP hormone levels are altered in response to increased blood volume and blood pressure. Antidiuretic hormone acts on the collecting ducts of the kidney to normalize the blood osmolarity. Thyrotropin is a thyroid-stimulating hormone that is released in response to low levels of the thyroid hormone.

A patient states, "This angiotensin-converting enzyme (ACE) inhibitor medication makes me urinate all the time. I didn't think it was a water pill." Which response would the nurse make?

A: "You are probably not taking your medication as prescribed." B: "This medication is a diuretic. I will print literature for you to review." ***C: "This medication causes greater excretion of water and sodium in your urine." D: "You must not be following your dietary restrictions. How much sodium are you eating?"

Which intervention would the nurse expect to be prescribed for a patient with hyponatremia?

A: 2-g sodium diet B: Administration of furosemide C: IV administration of 0.45% normal saline *** D: Small-volume IV infusions of 3% normal saline Rationale: A solution of 3% saline is hypertonic and is given in small volumes to replenish serum sodium; 0.45% saline is hypotonic and will further dilute serum sodium levels. Furosemide causes sodium loss in the kidneys and would further contribute to hyponatremia. A 2-g sodium diet restricts sodium intake; the goal of nutritional therapy with hyponatremia is to increase sodium intake.

After reviewing the health records of four assigned patients, which patient would the nurse determine has a risk for fluid overload?

A: 40-year-old woman with Crohn disease B: 50-year-old man with second-degree burns C: 60-year-old woman with nausea and vomiting *** D: 70-year-old man with chronic kidney disease

Which patient would the charge nurse assign to a licensed practical nurse/licensed vocational nurse (LPN/LVN)?

A: 44-year-old with congestive heart failure (CHF) who has gained 3 lb since the previous day B: 58-year-old with chronic renal failure (CRF) who has a serum potassium level of 6 mEq/L ***C: 76-year-old with poor skin turgor who has a serum osmolarity of 300 mOsm/L D: 80-year-old with 3+ peripheral edema and crackles throughout the posterior chest

Which nursing action would the nurse include in the care of an alert older adult who is mildly dehydrated?

A: Assessing weight and vital signs every 4 hours B: Restricting oral fluids if the patient is incontinent C: Advising the patient and family that strict bedrest is recommended because of fall risk *** D: Considering dietary restrictions and offering oral fluids every 2 hours Rationale: Oral fluid replacement is a priority when correcting mild to moderate dehydration in an alert patient who can swallow. Because risk for falls is increased, the patient should be offered assistance when ambulating. Bedrest is not recommended and may even contribute to other complications. Oral fluids should not be withheld because of incontinence. Initially, it is recommended to assess vital signs every 2 hours and weigh the patient every 8 hours.

For which classification of drugs would the nurse instruct a patient to increase intake of dietary potassium?

A: Beta blockers B: Corticosteroids C: Alpha antagonists *** D: Loop diuretics Rationale: High-ceiling (loop) diuretics are potassium-depleting drugs. The patient should increase intake of dietary potassium to compensate for this depletion. Alpha antagonists, beta blockers, and corticosteroids are not potassium-depleting drugs.

Which hormone regulates sodium balance? Select all that apply. One, some, or all responses may be correct.

A: Cortisol *** B: Aldosterone C: Angiotensin *** D: Natriuretic peptide (NP) *** E: Antidiuretic hormone (ADH) Rationale: Serum sodium levels are regulated by the kidneys under the influence of aldosterone, NP, and ADH. Low serum sodium levels inhibit the secretion of ADH and NP and trigger the secretion of aldosterone. This increases the serum sodium levels by increasing the reabsorption of sodium and enhancing water loss by the kidney. High serum sodium levels inhibit aldosterone secretion and stimulate the secretion of ADH and NP. These hormones increase the excretion of sodium and reabsorption of water by the kidney. Cortisol and angiotensin do not regulate serum sodium levels.

Which defense mechanism maintains blood flow to the vital organs during isotonic dehydration?

A: Decreased heart rate B: Decreased peripheral resistance *** C: Increased blood vessel constriction D: Increased pulmonary ventilation rate

Which consequence of fluid overload may result in seizures, coma, and death?

A: Decreased hematocrit B: Decreased hemoglobin C: Decreased serum proteins *** D: Decreased serum sodium Rationale: Fluid overload may cause a decrease in serum electrolytes such as sodium and potassium, which can lead to seizures, coma, and death. A decrease in hematocrit because of fluid overload decreases the serum osmolarity, which may cause pulmonary edema or heart failure. A decrease in hemoglobin increases the respiratory rate to meet the oxygen needs of the body. A decrease in serum proteins decreases the serum osmolarity and may cause pulmonary edema or heart failure.

Of the diagnoses documented in a patient's health record, which condition would the nurse attribute to the cause of the patient's sodium level of 130 mEq/L?

A: Diarrhea *** B: Heart failure C: Cushing syndrome D: Fever unknown origin Rationale: The patient is experiencing hyponatremia as the patient's sodium level is less than 136 mEq/L. Causes of hyponatremia include heart failure, being NPO, and excessive diaphoresis. Signs of hypernatremia would be diarrhea, Cushing syndrome, and a fever of unknown origin.

Which treatment would the nurse anticipate for a patient admitted to the ICU with a diagnosis of syndrome of inappropriate antidiuretic hormone secretion (SIADH)? Select all that apply. One, some, or all responses may be correct.

A: Digitalis *** B: Furosemide *** C: Tolvaptan *** D: Conivaptan E: Vasopressin F: Norepinephrine

Which intervention would the nurse expect the health care provider to prescribe for a patient with multiple fluid and electrolyte deficits secondary to a GI virus? Select all that apply. One, some, or all responses may be correct.

A: Give antihypertensives. B: Initiate fluid restrictions. C: Apply continuous oxygen. D: Administer loop diuretics. *** E: Start an IV solution of Ringer's lactate. Rationale: The nurse should anticipate starting IV fluids of Ringer's lactate as this would help replace some electrolytes. The patient would have a low blood pressure because of the fluid volume loss, so the nurse should not administer antihypertensives. The nurse should encourage oral fluids to replace losses, not restrict fluids. Oxygen would not be needed unless the patient's oxygen saturation dropped below 90%. Loop diuretics would worsen the fluid and electrolyte balance.

The nurse is reviewing serum electrolytes and blood chemistry for a newly admitted patient. Which result is of concern?

A: Glucose: 97 mg/dL B: Sodium: 143 mEq/L *** C: Potassium: 5.9 mEq/L D: Magnesium: 2.1 mEq/L Rationale: A potassium value of 5.9 mEq/L is high, and the patient should be assessed further. A glucose value of 97 mg/dL, a magnesium value of 2.1 mEq/L, and a sodium value of 143 mEq/L are normal values.

Which condition is more likely to cause dehydration than to cause fluid overload?

A: Heart failure B: Kidney failure *** C: Diabetes insipidus D: Psychiatric disorders Rationale: Diabetes insipidus is manifested as polyuria, which means the passage of frequent and large amounts of urine, leading to dehydration. Heart failure is manifested as peripheral edema, which refers to the retention of fluid in the lower extremities of the body. Kidney failure is manifested as decreasing or no production of urine, which causes retention of fluids in the body, resulting in fluid overload. Psychiatric disorders may lead to polydipsia, which also may lead to fluid overload.

Which condition would the nurse expect in the laboratory report of a patient with hypervolemia?

A: Hemostasis B: Homeostasis *** C: Hemodilution D: Hemoconcentration Rationale: Hypervolemia or fluid overload is characterized by decreased hemoglobin, hematocrit, and serum protein levels because of excessive water in the vascular space. This condition is called hemodilution. Hemostasis and homeostasis are not associated with hypervolemia or fluid overload. Hemoconcentration is the condition associated with hypovolemia or dehydration.

An older adult who is prescribed diuretics and laxatives and has a history of diabetes mellitus is brought to the emergency department in an unconscious state. Which condition would the nurse suspect?

A: Hyperkalemia *** B: Dehydration C: Fluid overload D: Water intoxication Rationale: Patients with diabetes mellitus may have polyuria, which causes loss of body water. Diuretics and laxatives also cause loss of body water, further potentiating dehydration, and may lead to unconsciousness in older-adult patients. Hypokalemia, not hyperkalemia, is common after diuretics and laxatives. Fluid overload is caused by excessive fluid intake or impaired renal or cardiac function. Water intoxication may result from excess intake of water without adequate intake of sodium.

For which purpose would a patient with edema receive a hyperosmotic IV solution?

A: Improve diffusion of electrolytes within cells. B: Reduce diffusion of potassium into the extracellular space. *** C: Pull excessive fluid from the interstitial space. D: Reduce filtration of body fluids. Rationale: Osmosis is the movement of water only through a semipermeable membrane down a concentration gradient. By infusing a hyperosmotic solution, interstitial fluid will be pulled into the plasma volume, reducing cerebral edema. Other physiologic actions, including diffusion and filtration, that help maintain intracellular and extracellular homeostasis are less influenced by the infusion of hyperosmotic IV solution.

A patient is brought in an unconscious state to the emergency department. The primary health care provider suspects dehydration. Which parameter in the laboratory results would indicate internal hemorrhage as a reason for dehydration?

A: Increased osmolarity *** B: Absence of hemoconcentration C: Elevated levels of blood components D: Decreased hemoglobin level Rationale: Hemoconcentration is not present when dehydration is caused by hemorrhage because loss of all blood and plasma products occurs together. Increased osmolarity and elevated levels of blood components are also characteristic findings of dehydration, but they do not indicate hemorrhage. Decreased blood hemoglobin indicates anemia but not dehydration.

A patient has had a total urine output of 200 mL in the past 24 hours. Which action would the nurse take first?

A: Insert an indwelling urinary catheter. *** B: Notify the primary health care provider. C: Encourage the patient to drink more fluids. D: Plan to measure daily weights. Rationale: The minimum amount of urine per day needed to excrete toxic waste products is 400 to 600 mL. With a urine output of 200 mL in 24 hours, a toxic buildup of nitrogen and lethal electrolyte imbalances can occur. The primary health care provider should be notified because additional tests or prescriptions might be necessary.

Which function does aldosterone serve?

A: It causes constriction of renal arterioles. *** B: It promotes resorption of water and sodium. C: It stimulates secretion of renin for the kidneys. D: It causes constriction of peripheral blood vessels. Rationale: Aldosterone promotes reabsorption of sodium and water into the body, which helps in maintaining blood pressure. Angiotensin II causes constriction of renal arterioles, resulting in low urine output. Factors such as low blood pressure, low blood volume, low oxygen, and low sodium trigger secretion of renin. Angiotensin II causes constriction of peripheral blood vessels and helps in maintaining perfusion to vital organs.

Which effect causes edema in a patient's dependent areas?

A: Large intercellular spaces B: Filtration of fluid in the cells *** C: Changes in normal hydrostatic pressure D: Equilibrium in solute concentration on each side of the cell Rationale: Edema develops with changes in normal hydrostatic pressure differences, such as in patients with right-sided heart failure.

A 77-year-old woman is brought to the emergency department after she has had diarrhea for 3 days. The patient reports that she is not eating or drinking well, but she is taking her diuretics for congestive heart failure. Her laboratory results include a potassium level of 7.0 mEq/L. Which goal would the health team set for this patient?

A: Maintaining proper diuresis and urine output B: Elevating serum potassium levels to a safe range C: Decreasing cardiac contractility and slowing the heart rate *** E: Restoring fluid balance by controlling causes of dehydration Rationale: Drug therapy for dehydration is directed at restoring fluid balance and controlling the causes of dehydration. Hyperkalemia (serum potassium level of 7.0 mEq/L) will slow the cardiac rate and cause decreased contractility of the heart. Serum potassium levels are already critically high, so they should not be elevated further. Excessive diuretic use is what has caused this patient's problems. What she needs now is to have electrolyte balance restored; for potassium, that is 3.5 to 5.0 mEq/L.

Which body system would the nurse reassess if a patient's laboratory result indicates a serum potassium level of 5.9 mEq/L?

A: Respiratory B: Genitourinary *** C: Cardiovascular D: Integumentary Rationale: Potassium controls conductivity within the heart, so the cardiovascular system of a patient with a serum potassium level of 5.9 mEq/L would be affected. The respiratory and genitourinary systems control acid-base balance. The integumentary system controls fluid and some sodium balance through perspiration.

When analysis of a patient's telemetry strip reveals a widened QRS complex with peaked T waves, which laboratory value would the nurse review before notifying the health care provider?

A: Sodium B: Calcium *** C: Potassium D: Magnesium Rationale: Hyperkalemia, or too much potassium, can cause cardiovascular changes, including peaked T waves and widened QRS complexes. Sodium does not affect the heart rhythm, but it does affect fluid volume. Calcium imbalances prolong the ST and QT intervals. Magnesium widens the QRS complex, but it does not cause peaked T waves.

Which laboratory value obtained from a patient's morning metabolic panel would the nurse report as abnormal?

A: Sodium 138 mEq/L *** B: Calcium 10.9 mEq/L C: Potassium 4.5 mEq/L D: Magnesium 2.0 mEq/L Rationale: The nurse should report the patient's calcium level; it is elevated at 10.9 mEq/L as the normal range is 9.0 to 10.5 mEq/L. A normal sodium level is 135 to 145 mEq/L; at 138 mEq/L, the patient's sodium level is within the normal range. A normal potassium level is 3.5 to 5.0 mEq/L; at 4.5 mEq/L, the patient's potassium level is within the normal range. The normal range for magnesium is 1.5 to 2.5 mEq/L; at 2.0 mEq/L, the patient's magnesium level is within the normal range.

Which laboratory value requires the nurse to notify the primary health care provider?

A: Sodium: 133 mEq/L B: Calcium: 9.0 mg/dL C: Potassium: 5.0 mEq/L *** D: Magnesium: 4.2 mEq/L Rationale: A magnesium level of 4.2 mEq/L is markedly elevated (normal is 1.8-2.6 mEq/L). Manifestations are not usually apparent until levels exceed 4 mEq/L. Patients with severe hypermagnesemia are in danger of cardiac arrest, so a level of 4.2 mEq/L requires prompt attention. A sodium level of 136 mEq/L is normal. A potassium level of 5.0 mEq/L is normal. A calcium level of 9.0 mg/dL is normal.

The nurse is reviewing laboratory values for a patient recently admitted to the medical-surgical unit. Which laboratory result is of concern?

A: Sodium: 137 mEq/L B: Chloride: 106 mEq/L C: Potassium: 3.5 mEq/L *** D: Magnesium: 6.2 mEq/L Rationale: A magnesium level of 6.2 mEq/L is greatly elevated. Patients with severe hypermagnesemia are in grave danger of cardiac arrest. The normal magnesium level is 1.8 to 2.6 mEq/L. The sodium, chloride, and potassium results are within normal limits.

Which condition is the major cause of death in patients with hypokalemia?

A: Stroke B: Renal failure C: Cardiac arrest *** D: Respiratory insufficiency Rationale: Respiratory changes may occur in patients with hypokalemia because of respiratory muscle weakness resulting in shallow respirations. The respiratory status of a patient with hypokalemia should be assessed at least every 2 hours because respiratory insufficiency is the major cause of death for these patients. A stroke is not a risk factor for hypokalemia. Hypokalemia does not cause renal failure; rather, hyperkalemia is caused by renal failure. Dysrhythmias may occur because of hypokalemia, but they are not the major cause of death in patients with hypokalemia.

Which assessment would the nurse perform to evaluate the effectiveness of rehydration therapy for a patient who was dehydrated? Select all that apply. One, some, or all responses may be correct.

A: Temperature *** B: Urinary output C: Bowel sounds *** D: Pulse rate and quality E: Level of consciousness

Which statement explains vascular dehydration?

A: Too much fluid loss B: Too little fluid intake *** C: Fluid shift from plasma to interstitial space D: Fluid shift from interstitial space to plasma

Which patient outcome indicates that a dose of furosemide was effective?

A: Weight gain B: Increased heart rate *** C: Increased urine output D: Decreased blood pressure (BP) Rationale: When giving furosemide, the nurse monitors the patient for response to drug therapy, including improved respiratory status, increased urine output, and a decrease in weight. Although a fall in the patient's BP may occur with the decrease in body fluid, this is not the most important assessment to be monitored. Urinary output is most important. Furosemide may cause a decrease in heart rate as it lowers the patient's body fluid, but this effect would take some time to note. Weight loss, rather than weight gain, is often the effect of furosemide, but it does not occur immediately.

Which clinical manifestation would the nurse associate with a patient's admitting diagnoses of heart failure and fluid overload? Select all that apply. One, some, or all responses may be correct.

A: Weight loss B: Hypotension C: Clear lung sounds *** D: Jugular vein distention E: Decreased respiratory rate Rationale: Signs of fluid overload include distended jugular neck veins. The patient would experience weight gain, not weight loss. The patient would experience hypertension, not hypotension. Because of excess fluid volume, the patient would have crackles in the lung fields with an increased respiratory rate.