Prep U 260 - Fluid & Electrolytes
The nurse is caring for a client diagnosed with bulimia. The client is being treated for a serum potassium level of 2.9 mEq/L. Which of the following statements made by the patient indicates the need for further teaching?
"I can use laxatives and enemas but only once a week."
A patient is ordered to receive hypotonic IV solution to provide free water replacement. Which of the following solutions will the nurse anticipate administering?
0.45% NaCl
Which of the following solutions is hypotonic?
0.45% NaCl. Explanation: Half-strength saline is hypotonic. Lactated Ringer's solution is isotonic. Normal saline (0.9% NaCl) is isotonic. A solution that is 5% NaCl is hypertonic.
A nurse correctly identifies a urine specimen with a pH of 4.3 as being which type of solution?
Acidic
To evaluate a client for hypoxia, the physician is most likely to order which laboratory test?
Arterial blood gas (ABG) analysis. Explanation: ABG analysis is the only test that evaluates gas exchange in the lungs, providing information about the client's oxygenation status.
The Emergency Department (ED) nurse is caring for a client with a possible acid-base imbalance. The physician has ordered an arterial blood gas (ABG). What is one of the most important indications of an acid-base imbalance that is shown in an ABG?
Bicarbonate
A group of nursing students are studying for a test over acid-base imbalance. One student asks another what the major chemical regulator of plasma pH is. What should the second student respond?
Bicarbonate-carbonic acid buffer system
Which nerve is implicated in the Chvostek's sign?
Facial Explanation: Chvostek's sign consists of twitching of muscles supplied by the facial nerve when the nerve is tapped about 2 cm anterior to the earlobe, just below the zygomatic arch.
A nurse is caring for a client with metastatic breast cancer who is extremely lethargic and very slow to respond to stimuli. The laboratory report indicates a serum calcium level of 12.0 mg/dl, a serum potassium level of 3.9 mEq/L, a serum chloride level of 101 mEq/L, and a serum sodium level of 140 mEq/L. Based on this information, the nurse determines that the client's symptoms are most likely associated with which electrolyte imbalance?
Hypercalcemia. Explanation: The normal reference range for serum calcium is 9 to 11 mg/dl. A serum calcium level of 12 mg/dl clearly indicates hypercalcemia.
An elderly client takes 40 mg of Lasix twice a day. Which electrolyte imbalance is the most serious adverse effect of diuretic use?
Hypokalemia Explanation: Hypokalemia (potassium level below 3.5 mEq/L) usually indicates a defict in total potassium stores. Potassium-losing diuretics, such as loop diuretics, can induce hypokalemia.
Oral intake is controlled by the thirst center, located in which of the following cerebral areas?
Hypothalamus
The nurse is instructing a patient with recurrent hyperkalemia about following a potassium-restricted diet. Which of the following patient statements indicates the need for additional instruction?
I will not salt my food, instead I'll use salt substitute."
The nurse is assessing residents at a summer picnic at the nursing facility. The nurse expresses concern due to the high heat and humidity of the day. Although the facility is offering the residents plenty of fluids for fluid maintenance, the nurse is most concerned about which?
Insensible fluid loss. Due to the high heat and humidity, geriatric clients are at a high risk for insensible fluid loss through perspiration and vapor in the exhaled air.
Which intervention is most appropriate for a client with an arterial blood gas (ABG) of pH 7.5, a partial pressure of arterial carbon dioxide (PaCO2) of 26 mm Hg, oxygen (O2) saturation of 96%, bicarbonate (HCO3-) of 24 mEq/L, and a PaO2 of 94 mm Hg?
Instruct the client to breathe into a paper bag.
Patients diagnosed with hypervolemia should avoid sweet or dry food because
It increases the patient's desire to consume fluid. Explanation: The management goal in hypervolemia is to reduce fluid volume. For this reason, fluid is rationed and the patient is advised to take a limited amount of fluid when thirsty. Sweet or dry food can increase the patient's desire to consume fluid.
With which condition should the nurse expect that a decrease in serum osmolality will occur?
Kidney failure
A physician orders an isotonic I.V. solution for a client. Which solution should the nurse plan to administer?
Lactated Ringer's solution
A client hospitalized for treatment of a pulmonary embolism develops respiratory alkalosis. Which clinical findings commonly accompany respiratory alkalosis?
Light-headedness or paresthesia. Explanation: The client with respiratory alkalosis may complain of light-headedness or paresthesia (numbness and tingling in the arms and legs). Nausea, vomiting, abdominal pain, and diarrhea may accompany respiratory acidosis.
Your client has a diagnosis of hypervolemia. What would be an important intervention that you would initiate?
Limit sodium and water intake.
The nurse is caring for a patient undergoing alcohol withdrawal. Which of the following serum laboratory values should the nurse monitor most closely?
Magnesium
A client has the following arterial blood gas (ABG) values: pH, 7.12; partial pressure of arterial carbon dioxide (PaCO2), 40 mm Hg; and bicarbonate (HCO3-), 15 mEq/L. These ABG values suggest which disorder?
Metabolic acidosis
The nurse is caring for a patient with diabetes type I who is having severe vomiting and diarrhea. What condition that exhibits blood values with a low pH and a low plasma bicarbonate concentration should the nurse assess for?
Metabolic acidosis
Your client's lab values are sodium 166 mEq/L, potassium 5.0 mEq/L, chloride 115 mEq/L, and bicarbonate 35 mEq/L. What condition is this client likely to have, judging by anion gap?
Metabolic acidosis. Explanation: The anion gap is the difference between sodium and potassium cations and the sum of chloride and bicarbonate anions. An anion gap that exceeds 16 mEq/L indicates metabolic acidosis. In this case, the anion gap is (166 + 5) minus (115 + 35), yielding 21 mEq/L, which suggests metabolic acidosis.
A client in the emergency department reports that he has been vomiting excessively for the past 2 days. His arterial blood gas analysis shows a pH of 7.50, partial pressure of arterial carbon dioxide (PaCO2) of 43 mm Hg, partial pressure of arterial oxygen (PaO2) of 75 mm Hg, and bicarbonate (HCO3-) of 42 mEq/L. Based on these findings, the nurse documents that the client is experiencing which type of acid-base imbalance?
Metabolic alkalosis Explanation: A pH over 7.45 with a HCO3- level over 26 mEq/L indicates metabolic alkalosis. Metabolic alkalosis is always secondary to an underlying cause and is marked by decreased amounts of acid or increased amounts of base HCO3-. The client isn't experiencing respiratory alkalosis because the PaCO2 is normal. The client isn't experiencing respiratory or metabolic acidosis because the pH is greater than 7.35.
A 64-year-old client is brought in to the clinic with thirsty, dry, sticky mucous membranes, decreased urine output, fever, a rough tongue, and lethargy. Serum sodium level is above 145 mEq/L. Should the nurse start salt tablets when caring for this client?
No, sodium intake should be restricted.
Which of the following electrolytes is a major cation in body fluid?
Potassium Explanation: Potassium is a major cation that affects cardiac muscle functioning.
A client comes to the emergency department with status asthmaticus. His respiratory rate is 48 breaths/minute, and he is wheezing. An arterial blood gas analysis reveals a pH of 7.52, a partial pressure of arterial carbon dioxide (PaCO2) of 30 mm Hg, PaO2 of 70 mm Hg, and bicarbonate (HCO3??') of 26 mEq/L. What disorder is indicated by these findings?
Respiratory alkalosis
A client admitted with acute anxiety has the following arterial blood gas (ABG) values: pH, 7.55; partial pressure of arterial oxygen (PaO2), 90 mm Hg; partial pressure of arterial carbon dioxide (PaCO2), 27 mm Hg; and bicarbonate (HCO3-), 24 mEq/L. Based on these values, the nurse suspects:
Respiratory alkalosis. Explanation: This client's above-normal pH value indicates alkalosis. The below-normal PaCO2 value indicates acid loss via hyperventilation; this type of acid loss occurs only in respiratory alkalosis.
The nurse is caring for a patient in the intensive care unit (ICU) following a saltwater near-drowning event. The client is restless, lethargic, and demonstrating tremors. Additional assessment findings include swollen dry tongue, flushed skin, and peripheral edema. The nurse anticipated that the patient's serum sodium value would be which of the following?
Serum bicarbonate of 28 mEq/L Explanation: Evaluation of arterial blood gases reveals a pH greater than 7.45 and a serum bicarbonate concentration greater than 26 mEq/L.
To compensate for decreased fluid volume (hypovolemia), the nurse can anticipate which response by the body?
Tachycardia
A 57-year-old homeless female with a history of alcohol abuse has been admitted to your hospital unit with signs and symptoms of hypovolemia—minus the weight loss. She exhibits a localized enlargement of her abdomen. What condition could she be presenting?
Third-spacing. Explanation: Third-spacing describes the translocation of fluid from the intravascular or intercellular space to tissue compartments, where it becomes trapped and useless.
Treatment of FVE involves dietary restriction of sodium. Which of the following food choices would be part of a low-sodium diet, mild restriction (2 to 3 g/day)?
Three ounces of light or dark meat chicken, 1 cup of spaghetti and a garden salad
A patient is diagnosed with hypocalcemia. The nurse advises the patient and his family to immediately report the most characteristic manifestation. What is the most characteristic manifestation?
Tingling or twitching sensation in the fingers
A nurse is reviewing a report of a client's routine urinalysis. Which value requires further investigation?
Urine pH of 3.0 Explanation: Normal urine pH is 4.5 to 8; therefore, a urine pH of 3.0 is abnormal and requires further investigation. Urine specific gravity normally ranges from 1.010 to 1.025, making this client's value normal.
When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis?
pH 7.48
The nurse is analyzing the arterial blood gas (AGB) results of a patient diagnosed with severe pneumonia. Which of the following ABG results indicates respiratory acidosis?
pH: 7.20, PaCO2: 65 mm Hg, HCO3-: 26 mEq/L. Respiratory acidosis = pH is less than 7.35 and the PaCO2 is greater than 42 mm Hg and a compensatory increase in the plasma HCO3-. Metabolic acidosis = pH: 7.32, PaCO2: 40 mm Hg, HCO3-: 18 mEq/L. Respiratory alkalosis = pH: 7.50, PaCO2: 30 mm Hg, and HCO3-: 24 mEq/L. Normal result/no imbalance = pH 7.42, PaCO2: 45 mm Hg, and HCO3-: 22 mEq/L.
You are caring for a 72-year-old client who has been admitted to your unit for a fluid volume imbalance. You know which of the following is the most common fluid imbalance in older adults?
Dehydration. Because of reduced thirst sensation that often accompanies aging, older adults tend to drink less water.
Which of the following is a correct route of administration for potassium?
Oral. Explanation: Potassium may be administered through the oral route. Potassium is never administered by IV push or intramuscularly to avoid replacing potassium too quickly. Potassium is not administered subcutaneously.
A 160-pound patient, diagnosed with hypovolemia, is weighed every day. The health care provider asked to be notified if the patient loses 1,000 mL of fluid in 24 hours. Choose the weight that would be consistent with this amount of fluid loss.
158 lbs. Explanation: A loss of 0.5 kg or 1 lb represents a fluid loss of about 500 mL. Therefore, a loss of 1,000 mL would be equivalent to the loss of 2 lbs (160 - 2 = 158 lbs).
A client with an intravenous infusion is rubbing his arm. The nurse assesses the site and decides to discontinue the current infusion because of concern that the client has developed phlebitis. Which of the following clinical manifestations would the nurse assess with phlebitis? Select all that apply.
• Tender area around the insertion site • Reddended area along the path of the vein
A 42-year-old client has chronic hypo natremia, which requires weekly blood labs to keep him from lapsing into convulsions or a coma. What is the level of serum sodium below which convulsions or coma can occur?
135 mEq/L Explanation: Normal serum concentration level = 135 to 145 mEq/L. Manifestations = mental confusion, muscular weakness, anorexia, restlessness, elevated body temperature, tachycardia, nausea, vomiting, and personality changes. Convulsions or coma can occur, if the deficit is severe. Hyper natremia = serum sodium level above 145 mEq/L.
Below which serum sodium level may convulsions or coma can occur?
135 mEq/L Explanation: Normal serum concentration level ranges from 135 to 145 mEq/L. When the level dips below 135 mEq/L, there is hyponatremia.
To confirm an acid-base imbalance, it is necessary to assess which of the following findings from the results of a client's arterial blood gas (ABG) results? Select all that apply.
155 mEq/L Explanation: Hypernatremia is a serum sodium level higher than 145 mEq/L (145 mmol/L). A cause of hypernatremia is near drowning in seawater (which contains a sodium concentration of approximately 500 mEq/L). S/S include thirst, elevated body temperature, swollen dry tongue and sticky mucous membranes, hallucinations, lethargy, restlessness, irritability, simple partial or tonic-clonic seizures, pulmonary edema, hyperreflexia, twitching, nausea, vomiting, anorexia, elevated pulse, and elevated blood pressure.
A patient who is semiconscious presents with restlessness and weakness. The nurse assesses a dry, swollen tongue and a body temperature of 99.3°F. The urine specific gravity is 1.020. What is the most likely serum sodium value for this patient?
155 mEq/L. Explanation: In hypernatremia, the serum sodium level exceeds 145 mEq/L (145 mmol/L) and the serum osmolality exceeds 300 mOsm/ kg (300 mmol/L).
A nurse can estimate serum osmolality at the bedside by using a formula. A patient who has a serum sodium level of 140 mEq/L would have a serum osmolality of:
280 mOsm/kg. Explanation: Serum osmolality can be estimated by doubling the serum sodium or using the formula: Na × 2 = glucose/18 + BUN/3. Therefore, the nurse could estimate a serum osmolality of 280 mOsm/kg by doubling the serum sodium value of 140 mEq/L.
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 52-year-old with diarrhea
The nurse is correct to state that a client's body needs to have adequate nutrition to maintain energy. Which type of transport of dissolved substances requires adenosine triphosphate (ATP)?
Active transport
The nurse is caring for a client with laboratory values indicating dehydration. Which clinical symptom is consistent with the dehydration?
Dark, concentrated urine
What foods can the nurse recommend for the patient with hypokalemia?
Fruits such as bananas and apricots
Which of the following conditions does the nurse need to confirm when he or she taps the facial nerve of a client who has dysphagia?
Hypomagnesemia. Explanation: If there is a unilateral spasm of facial muscles when the nurse taps over the facial muscle, it is known as Chvostek's sign, which is a sign of hypocalcemia and hypomagnesemia. The additional symptom of dysphagia reinforces the possibility of hypomagnesemia rather than hypocalcemia.
Which sign suggests that a client with the syndrome of inappropriate antidiuretic hormone (SIADH) secretion is experiencing complications?
Jugular vein distention
A client in the emergency department reports that he has been vomiting excessively for the past 2 days. His arterial blood gas analysis shows a pH of 7.50, partial pressure of arterial carbon dioxide (PaCO2) of 43 mm Hg, partial pressure of arterial oxygen (PaO2) of 75 mm Hg, and bicarbonate (HCO3-) of 42 mEq/L. Based on these findings, the nurse documents that the client is experiencing which type of acid-base imbalance?
Metabolic alkalosis
A priority nursing intervention for a client with hypervolemia involves which of the following?
Monitoring respiratory status for signs and symptoms of pulmonary complications. Explanation: Hypervolemia, or fluid volume excess (FVE), refers to an isotonic expansion of the extracellular fluid. Nursing interventions for FVE include measuring intake and output, monitoring weight, assessing breath sounds, monitoring edema, and promoting rest. The most important intervention = monitoring the respiratory status for any signs of pulmonary congestion. Breath sounds are assessed at regular intervals.
The nurse is reviewing client lab work for a critical lab value. Which value is called to the physician for additional orders?
Potassium: 5.8 mEq/L Normal potassium level is 3.5 to 5.5 mEq/L. Elevated potassium levels can lead to muscle weakness, paresthesias, and cardiac dysrhythmias.
The calcium level of the blood is regulated by which mechanism?
Parathyroid hormone (PTH) Explanation: The serum calcium level is controlled by PTH and calcitonin.
A client with a suspected overdose of an unknown drug is admitted to the emergency department. Arterial blood gas values indicate respiratory acidosis. What should the nurse do first?
Prepare to assist with ventilation.
The nurse is analyzing the electrocardiographic (ECG) rhythm tracing of a patient experiencing hypercalcemia. Which of the following ECG changes is typically associated with this electrolyte imbalance?
Prolonged PR intervals Explanation: Cardiovascular changes associated with hypercalcemia may include a variety of dysrhythmias (e.g., heart blocks) and shortening of the QT interval and the ST segment. The PR interval is sometimes prolonged.
Which of the following arterial blood gas results would be consistent with metabolic alkalosis?
Serum bicarbonate of 28 mEq/L. Explanation: Evaluation of arterial blood gases reveals a pH greater than 7.45 and a serum bicarbonate concentration greater than 26 mEq/L.
The nurse is caring for a patient diagnosed with hyperchloremia. Signs and symptoms of hyperchloremia include which of the following? Select all that apply.
Tachypnea, Weakness, and Lethargy. Explanation: The signs and symptoms of hyperchloremia are the same as those of metabolic acidosis: hypervolemia and hypernatremia. Tachypnea; weakness; lethargy; deep, rapid respirations; diminished cognitive ability; and hypertension occur. If untreated, hyperchloremia can lead to a decrease in cardiac output, dysrhythmias, and coma. A high chloride level is accompanied by a high sodium level and fluid retention.
A nurse is conducting an initial assessment on a client with possible tuberculosis. Which assessment finding indicates a risk factor for tuberculosis?
The client had a liver transplant 2 years ago. A history of immunocompromised status, such as that which occurs with liver transplantation, places the client at a higher risk for contracting tuberculosis.
A client has a serum calcium level of 7.2 mg/dl. During the physical examination, the nurse expects to assess:
Trousseau's sign. Explanation: Hypocalcemia, an electrolyte imbalance that causes Trousseau's sign (carpopedal spasm induced by inflating the blood pressure cuff above systolic pressure). Homans' sign (pain on dorsiflexion of the foot) indicates deep vein thrombosis. Hegar's sign (softening of the uterine isthmus). Goodell's sign (cervical softening) are probable signs of pregnancy.
Which of the following would be appropriate nursing interventions for a client with hypokalemia? Select all that apply.
• Offer a diet with fruit juices and citrus fruits. • Monitor intake and output every shift. Hypokalemia is a potassium level less than 3.5 mEq/L.
A client was admitted to your unit with a diagnosis of hypovolemia. When it is time to complete discharge teaching, which of the following will the nurse teach the client and his family? Select all that apply.
• Respond to thirst • Drink water as an inexpensive way to meet fluid needs. • Drink at least eight glasses of fluid each day.