Chapter 13: Fluid and Electrolytes: Balance and Disturbance
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 Explanation: This client's pH value is below normal, indicating acidosis. The HCO3- value also is below normal, reflecting an overwhelming accumulation of acids or excessive loss of base, which suggests metabolic acidosis. The PaCO2 value is normal, indicating absence of respiratory compensation. These ABG values eliminate respiratory alkalosis, respiratory acidosis, and metabolic alkalosis.
A client with respiratory acidosis is admitted to the intensive care unit for close observation. What client complication associated with respiratory acidosis would the nurse observe?
papilledema Explanation: If respiratory acidosis is severe, intracranial pressure may rise, causing papilledema. Stroke and hyperglycemia are not associated with respiratory acidosis. Seizures may complicate respiratory alkalosis, not respiratory acidosis.
The calcium concentration in the blood is regulated by which mechanism?
Parathyroid hormone (PTH) Explanation: The serum calcium concentration is controlled by PTH and calcitonin. The thyroid hormone, adrenal gland, or androgens do not regulate the calcium concentration in the blood.
A client is to receive hypotonic IV solution in order to provide free water replacement. Which solution does the nurse anticipate administering?
0.45% NaCl Explanation: Half-strength saline (0.45%) is hypotonic. Hypotonic solutions are used to replace cellular fluid because it is hypotonic compared with plasma. Another is to provide free water to excrete body wastes. At times, hypotonic sodium solutions are used to treat hypernatremia and other hyperosmolar conditions. Lactated Ringer solution and normal saline (0.9% NaCl) are isotonic. A solution that is 5% NaCl is hypertonic.
The nurse is caring for a geriatric client in the home setting. Due to geriatric changes decreasing thirst, the nurse is likely to see a decrease in which fluid location which contains the most body water?
Intracellular fluid Explanation: About 60% of the adult human body is water. Most body water is located within the cell (intracellular fluid). Due to several physiological changes of aging, geriatric clients have less bodily fluids.
A client with chronic renal failure has a serum potassium level of 6.8 mEq/L. What should the nurse assess first?
Pulse Explanation: An elevated serum potassium level may lead to a life-threatening cardiac arrhythmia, which the nurse can detect immediately by palpating the pulse. In addition to assessing the client's pulse, the nurse should place the client on a cardiac monitor because an arrythmia can occur suddenly. The client's blood pressure may change, but only as a result of the arrhythmia. Therefore, the nurse should assess blood pressure later. The nurse also may delay assessing respirations and temperature because these aren't affected by the serum potassium level.
A client with hypervolemia asks the nurse by what mechanism the sodium-potassium pump will move the excess body fluid. What is the nurse's best answer?
active transport Explanation: Active transport is the physiologic pump maintained by the cell membrane that results in the movement of fluid from an area of lower concentration to one of higher concentration. Active transport requires adenosine triphosphate (ATP) for energy. The sodium-potassium pump actively moves sodium against the concentration gradient out of the cell, and fluid follows. Passive osmosis does not require energy for transport. Free flow is the natural transport of water. Passive elimination is a filter process carried out in the kidneys.
A client presents with anorexia, nausea and vomiting, deep bone pain, and constipation. The following are the client's laboratory values. sodium 137 mEq/L (137 mmol/L)potassium 4.6 mEq/L (4.6 mmol/L)chloride 94 mEq/L (94 mmol/L)calcium 12.9 mg/dL (3.2 mmol/L) What laboratory value is of highest concern to the nurse?
calcium 12.9 mg/dL (3.2 mmol/L) Explanation: More than 99% of the body's calcium is found in the skeletal system. Hypercalcemia, or calcium levels exceeding 10.2 mg/dL (2.5 mmol/L), can be a dangerous imbalance. The client presents with anorexia, nausea and vomiting, constipation, abdominal pain, bone pain, and confusion. The listed sodium, potassium, and chloride levels are within normal limits.
Which set of arterial blood gas (ABG) results requires further investigation?
pH 7.49, PaCO2 30 mm Hg, PaO2 89 mm Hg, and HCO3- 18 mEq/L Explanation: The ABG results pH 7.49, PaCO2 30 mm Hg, PaO2 89 mm Hg, and HCO3- 18 mEq/L indicate respiratory alkalosis. The pH level is increased, and the HCO3- and PaCO2 levels are decreased. Normal values are pH 7.35 to 7.45; PaCO2 35 to 45 mm Hg; HCO3- 22 to 26 mEq/L.
A client has chronic hyponatremia, which requires weekly laboratory monitoring to prevent the client lapsing into convulsions or a coma. What is the level of serum sodium at which a client can experience these side effects?
114 mEq/L Explanation: Hyponatremia occurs when the serum sodium level dips below 135 mEq/L. When serum sodium levels fall below 115mEq/L, mental confusion, muscular weakness, anorexia, restlessness, elevated body temperature, tachycardia, nausea, vomiting, personality changes, convulsions, or coma can occur. A serum sodium level of 148 mEq/L would indicate hypernatremia. Normal serum concentration levels range from 135 to 145 mEq/L.
What foods can the nurse recommend for the patient with hyperkalemia?
Apples and berries Explanation: Sources of potassium include fruit juices and bananas, melon, citrus fruits, fresh and frozen vegetables, lean meats, milk, and whole grains (Crawford & Harris, 2011b).
A client has a respiratory rate of 38 breaths/min. What effect does breathing faster have on arterial pH level?
Increases arterial pH Explanation: Respiratory alkalosis is always caused by hyperventilation, which is a decrease in plasma carbonic acid concentration. The pH is elevated above normal as a result of a low PaCO2.
Which of the following is the most common cause of symptomatic hypomagnesemia in the United States?
Alcoholism Explanation: Alcoholism is currently the most common cause of symptomatic hypomagnesemia in the United States. Any disruption in small bowel function, as in intestinal resection or inflammatory bowel disease, can lead to hypomagnesemia.
The nurse is caring for a client with a serum sodium concentration of 113 mEq/L (113 mmol/L). The nurse should monitor the client for the development of which condition?
Confusion Explanation: Normal serum concentration ranges from 135 to 145 mEq/L (135-145 mmol/L). Hyponatremia exists when the serum concentration decreases below 135 mEq/L (135 mmol/L). When the serum sodium concentration decreases to <115 mEq/L (<115 mmol/L), signs of increasing intracranial pressure, such as lethargy, confusion, muscle twitching, focal weakness, hemiparesis, papilledema, seizures, and death, may occur. General manifestations of hyponatremia include poor skin turgor, dry mucosa, headache, decreased saliva production, orthostatic fall in blood pressure, nausea, vomiting, and abdominal cramping. Neurologic changes, including altered mental status, status epilepticus, and coma, are probably related to cellular swelling and cerebral edema associated with hyponatremia. Hallucinations are associated with increased serum sodium concentrations.
A client was admitted to the 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 family? Select all that apply.
Drink at least eight glasses of fluid each day. Drink water as an inexpensive way to meet fluid needs. Respond to thirst Explanation: In addition, the nurse teaches clients who have a potential for hypovolemia and their families to respond to thirst because it is an early indication of reduced fluid volume; consume at least 8 to 10 (8 ounce) glasses of fluid each day and more during hot, humid weather; drink water as an inexpensive means to meet fluid requirements; and avoid beverages with alcohol and caffeine because they increase urination and contribute to fluid deficits.
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. Explanation: The ABG results reveal respiratory alkalosis. The best intervention to raise the PaCO2 level would be to have the client breathe into a paper bag. Administering a decongestant, offering fluids frequently, and administering supplemental oxygen wouldn't raise the lowered PaCO2 level.
With which condition should the nurse expect that a decrease in serum osmolality will occur?
Kidney failure Explanation: Failure of the kidneys results in multiple fluid and electrolyte abnormalities including fluid volume overload. If renal function is so severely impaired that pharmacologic agents cannot act efficiently, other modalities are considered to remove sodium and fluid from the body.
The nurse is caring for a client undergoing alcohol withdrawal. Which serum laboratory value should the nurse monitor most closely?
Magnesium Explanation: Chronic alcohol abuse is a major cause of symptomatic hypomagnesemia in the United States. The serum magnesium concentration should be measured at least every 2 or 3 days in clients undergoing alcohol withdrawal. The serum magnesium concentration may be normal at admission but may decrease as a result of metabolic changes, such as the intracellular shift of magnesium associated with intravenous glucose administration.
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 Explanation: Metabolic acidosis is a common clinical disturbance characterized by a low pH (increased H+ concentration) and a low plasma bicarbonate concentration. Metabolic alkalosis is a clinical disturbance characterized by a high pH (decreased H+ concentration) and a high plasma bicarbonate concentration. Respiratory acidosis is a clinical disorder in which the pH is less than 7.35 and the PaCO2 is greater than 42 mm Hg and a compensatory increase in the plasma HCO3 occurs. Respiratory alkalosis is a clinical condition in which the arterial pH is greater than 7.45 and the PaCO2 is less than 38 mm Hg
A client with cancer is being treated on the oncology unit for bilateral breast cancer. The client is undergoing chemotherapy. The nurse notes the client's serum calcium concentration is 12.3 mg/dL (3.08 mmol/L). Given this laboratory finding, the nurse should suspect that the
malignancy is causing the electrolyte imbalance. Explanation: The client's laboratory findings indicate hypercalcemia. Hypercalcemia is defined as a calcium concentration >10.2 mg/dL (>2.6 mmol/L).The most common causes of hypercalcemia are malignancies and hyperparathyroidism. Malignant tumors can produce hypercalcemia through a variety of mechanisms. The client's calcium level is elevated; there is no indication that the client's diet is lacking in calcium-rich food products. Hyperaldosteronism is not associated with a calcium imbalance. Alcohol abuse is associated with hypocalcemia.
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.
A nurse correctly identifies a urine specimen with a pH of 4.3 as being which type of solution?
Acidic Explanation: Normal urine pH is 4.5 to 8.0; a value of 4.3 reveals acidic urine pH. A pH above 7.0 is considered an alkaline or basic solution. A pH of 7.0 is considered neutral.
An elderly client takes 40 mg of furosemide 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 deficit in total potassium stores. Potassium-losing diuretics, such as furosemide, can induce hypokalemia. Hyperkalemia refers to increased potassium levels. Loop diuretics can bring about lower sodium levels, not hypernatremia. Furosemide does not affect phosphorus levels
Which electrolyte is a major cation in body fluid?
Potassium Explanation: Potassium is a major cation that affects cardiac muscle functioning. Chloride, bicarbonate, and phosphate are anions.
The nurse is caring for a client with a serum potassium concentration of 6.0 mEq/L (6.0 mmol/L) and a fluid volume excess. The client is ordered to receive oral sodium polystyrene sulfonate and furosemide. What other order should the nurse anticipate giving?
Discontinue the intravenous lactated Ringer solution. Explanation: The lactated Ringer intravenous (IV) fluid is contributing to both the fluid volume excess and the hyperkalemia. In addition to the volume of IV fluids contributing to the fluid volume excess, lactated Ringer solution contains more sodium than daily requirements, and excess sodium worsens fluid volume excess. Lactated Ringer solution also contains potassium, which would worsen the hyperkalemia.
A nurse is assessing a client with syndrome of inappropriate antidiuretic hormone. Which finding requires further action?
Jugular vein distention Explanation: Jugular vein distention requires further action because this finding signals vascular fluid overload. Tetanic contractions aren't associated with this disorder, but weight gain and fluid retention from oliguria are. Polyuria is associated with diabetes insipidus, which occurs with inadequate production of antidiuretic hormone.
When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis?
pH 7.48 Explanation: Metabolic alkalosis is a clinical disturbance characterized by a high pH and high plasma bicarbonate concentration. The HCO value is below normal. The PaCO value and the oxygen saturation level are within a normal range.
A nurse is providing an afternoon shift report and relates morning assessment findings to the oncoming nurse. Which daily assessment data is necessary to determine changes in the client's hypervolemia status?
weight Explanation: Daily weight provides the ability to monitor fluid status. A 2-lb (0.9 kg) weight gain in 24 hours indicates that the client is retaining 1 L of fluid. Also, the loss of weight can indicate a decrease in edema. Vital signs do not always reflect fluid status. Edema could represent a shift of fluid within body spaces and not a change in weight. Intake and output do not account for unexplainable fluid loss.
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 weight of a client with congestive heart failure is monitored daily and entered into the medical record. In a 24-hour period, the client's weight increased by 2 lb. How much fluid is this client retaining?
1 L Explanation: A 2-lb weight gain in 24 hours indicates that the client is retaining 1L of fluid.
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.
Reddened area along the path of the vein Tender area around the insertion site Explanation: Phlebitis is inflammation of a vein and is characterized by a reddened, warm area around an insertion site or along the path of a vein. The involved area is also tender and swollen. The nurse assesses infusion sites and determines the proper action to take. If indications lead to suspected phlebitis, the nurse will discontinue the intravenous line and restart with a different vessel.
The nurse is caring for a client in heart failure with signs of hypervolemia. Which vital sign is indicative of the disease process?
Elevated blood pressure Explanation: Indicative of hypervolemia is a bounding pulse and elevated blood pressure due to the excess volume in the system. Respirations are not typically affected unless there is fluid accumulation in the lungs. Temperature is not generally affected.
Which of the following electrolytes is the primary determinant of extracellular fluid (ECF) osmolality?
Sodium Explanation: Sodium is the primary determinant of ECF osmolality. Sodium plays a major role in controlling water distribution throughout the body because it does not easily cross the intracellular wall membrane and because of its abundance and high concentration in the body. Potassium, calcium, and magnesium are not primary determinants of ECF osmolality.
A patient with diabetes insipidus presents to the emergency room for treatment of dehydration. The nurse knows to review serum laboratory results for which of the diagnostic indicators?
Sodium level of 150 mEq/L Explanation: Hypernatremia (normal serum sodium is 135 to 145 mEq/L) is consistent with increased fluid loss and dehydration in diabetes insipidus.
The nurse is caring for a client diagnosed with chronic obstructive pulmonary disease (COPD) and experiencing respiratory acidosis. The client asks what is making the acidotic state. The nurse is most correct to identify which result of the disease process that causes the fall in pH?
The lungs are not able to blow off carbon dioxide. Explanation: In clients with chronic respiratory acidosis, the client is unable to blow off carbon dioxide leaving in increased amount of hydrogen in the system. The increase in hydrogen ions leads to acidosis. In COPD, the client is able to breathe in oxygen and gas exchange can occur, it is the lungs ability to remove the carbon dioxide from the system. Although individuals with COPD frequently have a history of smoking, cilia is not the cause of the acidosis.
A client with emphysema is at a greater risk for developing which acid-base imbalance?
chronic respiratory acidosis Explanation: Respiratory acidosis, which may be either acute or chronic, is caused by excess carbonic acid, which causes the blood pH to drop below 7.35. Chronic respiratory acidosis is associated with disorders such as emphysema, bronchiectasis, bronchial asthma, and cystic fibrosis.
Early signs of hypervolemia include
increased breathing effort and weight gain. Explanation: Early signs of hypervolemia are weight gain, elevated blood pressure, and increased breathing effort. Eventually, fluid congestion in the lungs leads to moist breath sounds. One of the earliest symptoms of hypovolemia is thirst.
A client who complains of an "acid stomach" has been taking baking soda (sodium bicarbonate) regularly as a self-treatment. This may place the client at risk for which acid-base imbalance?
metabolic alkalosis Explanation: Metabolic alkalosis results in increased plasma pH because of accumulated base bicarbonate or decreased hydrogen ion concentrations. The client's regular use of baking soda (sodium bicarbonate) may create a risk for this condition. Metabolic acidosis refers to decreased plasma pH because of increased organic acids (acids other than carbonic acid) or decreased bicarbonate. Respiratory acidosis, which may be either acute or chronic, is caused by excess carbonic acid. Respiratory alkalosis results from a carbonic acid deficit that occurs when rapid breathing releases more CO2 than necessary with expired air.
A patient is admitted with severe vomiting for 24 hours as well as weakness and "feeling exhausted." The nurse observes flat T waves and ST-segment depression on the electrocardiogram. Which potassium level does the nurse observe when the laboratory studies are complete?
2.5 mEq/L Explanation: Symptoms of hypokalemia (<3.0 mEq/L) include fatigue, anorexia, nausea and vomiting, muscle weakness, polyuria, decreased bowel motility, ventricular asystole or fibrillation, paresthesias, leg cramps, hypotension, ileus, abdominal distention, and hypoactive reflexes. Electrocardiogram findings associated with hypokalemia include flattened T waves, prominent U waves, ST depression, and prolonged PR interval.
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 Explanation: Electrolytes are in both intracellular and extracellular water. Electrolyte deficiency occurs from an inadequate intake of food, conditions that deplete water such as nausea and vomiting, or disease processes that cause an excess of electrolyte amounts. The 52-year-old with diarrhea would be the client most likely to have an electrolyte imbalance. The orthopedic client will not likely have an electrolyte imbalance. Myocardial infarction clients will occasionally have electrolyte imbalance, but this is the exception rather than the rule.
To evaluate a client for hypoxia, the physician is most likely to order which laboratory test?
Arterial blood gas (ABG) analysis Explanation: Red blood cell count, sputum culture, total hemoglobin, and ABG analysis all help evaluate a client with respiratory problems. However, ABG analysis is the only test that evaluates gas exchange in the lungs, providing information about the client's oxygenation status.
A client reports tingling in the fingers as well as feeling depressed. The nurse assesses positive Trousseau's and Chvostek's signs. Which decreased laboratory results does the nurse observe when the client's laboratory work has returned?
Calcium Explanation: Calcium deficit is associated with the following symptoms: numbness and tingling of the fingers, toes, and circumoral region; positive Trousseau's sign and Chvostek's sign; seizures, carpopedal spasms, hyperactive deep tendon reflexes, irritability, bronchospasm, anxiety, impaired clotting time, decreased prothrombin, diarrhea, and hypotension. Electrocardiogram findings associated with hypocalcemia include prolonged QT interval and lengthened ST.
The physician has prescribed 0.9% sodium chloride IV for a hospitalized client in metabolic alkalosis. Which nursing actions are required to manage this client? Select all that apply.
Compare ABG findings with previous results. Maintain intake and output records. Document presenting signs and symptoms. Explanation: Metabolic alkalosis results in increased plasma pH because of accumulated base bicarbonate or decreased hydrogen ion concentrations. The result is retention of sodium bicarbonate and increased base bicarbonate. Nursing management includes documenting all presenting signs and symptoms to provide accurate baseline data, monitoring laboratory values, comparing ABG findings with previous results (if any), maintaining accurate intake and output records to monitor fluid status, and implementing prescribed medical therapy.
Which findings indicate that a client has developed water intoxication secondary to treatment for diabetes insipidus?
Confusion and seizures Explanation: Classic signs of water intoxication include confusion and seizures, both of which are caused by cerebral edema. Weight gain will also occur. Sunken eyeballs, thirst, and increased BUN levels indicate fluid volume deficit. Spasticity, flaccidity, and tetany are unrelated to water intoxication.
The nurse is caring for a 72-year-old client who has been admitted to the unit for a fluid volume imbalance. The nurse knows which of the following is the most common fluid imbalance in older adults?
Dehydration Explanation: The most common fluid imbalance in older adults is dehydration. Because of reduced thirst sensation that often accompanies aging, older adults tend to drink less water. Use of diuretic medications, laxatives, or enemas may also deplete fluid volume in older adults. Chronic fluid volume deficit can lead to other problems such as electrolyte imbalances.
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). Headache, blurry vision, abdominal pain, and diarrhea may accompany respiratory acidosis. Hallucinations and tinnitus rarely are associated with respiratory alkalosis or any other acid-base imbalance.
The nurse is caring for a client with multiple organ failure and in metabolic acidosis. Which pair of organs is responsible for regulatory processes and compensation?
Lungs and kidney Explanation: The lungs and kidneys facilitate the ratio of bicarbonate to carbonic acid. Carbon dioxide is one of the components of carbonic acid. The lungs regulate carbonic acid levels by releasing or conserving CO2 by increasing or decreasing the respiratory rate. The kidneys assist in acid-base balance by retaining or excreting bicarbonate ions.
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 in the list involves monitoring the respiratory status for any signs of pulmonary congestion. Breath sounds are assessed at regular intervals.
The nurse is caring for a client with severe diarrhea. The nurse recognizes that the client is at risk for developing which acid-base imbalance?
Metabolic acidosis Explanation: The client is at risk for developing metabolic acidosis. Metabolic acidosis is caused by diarrhea, lower intestinal fistulas, ureterostomies, and use of diuretics; early renal insufficiency; excessive administration of chloride; and the administration of parenteral nutrition without bicarbonate or bicarbonate-producing solutes (e.g., lactate).
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.
Which is the preferred route of administration for potassium?
Oral Explanation: When the client cannot ingest sufficient potassium by consuming foods that are high in potassium, administering oral potassium is ideal because oral potassium supplements are absorbed well. Administration by IV is done with extreme caution using an infusion pump, with the patient monitored by continuous ECG. To avoid replacing potassium too quickly, potassium is never administered by IV push or intramuscularly. Potassium is not administered subcutaneously.
A client is being treated in the ICU 24 hours after having a radical neck dissection completed. The client's serum calcium concentration is 7.6 mg/dL (1.9 mmol/L). Which physical examination finding is consistent with this electrolyte imbalance?
Presence of Trousseau sign Explanation: After radical neck resection, a client is prone to developing hypocalcemia. Hypocalcemia is defined as a serum value <8.6 mg/dL (<2.15 mmol/L). Signs and symptoms of hypocalcemia include Chvostek sign, which consists of muscle twitching enervated by the facial nerve when the region that is about 2 cm anterior to the earlobe, just below the zygomatic arch, is tapped; and a positive Trousseau sign can be elicited by inflating a blood pressure cuff on the upper arm to about 20 mm Hg above systolic pressure; within 2 to 5 minutes, carpal spasm (an adducted thumb, flexed wrist and metacarpophalangeal joints, and extended interphalangeal joints with fingers together) will occur as ischemia of the ulnar nerve develops. Slurred speech and muscle weakness are signs of hypercalcemia.
A nurse is caring for a client admitted with a diagnosis of exacerbation of myasthenia gravis. Upon assessment of the client, the nurse notes the client has severely depressed respirations. The nurse would expect to identify which acid-base disturbance?
Respiratory acidosis Explanation: Respiratory acidosis is always from inadequate excretion of CO2 with inadequate ventilation, resulting in elevated plasma CO2 concentrations. Respiratory acidosis can occur in diseases that impair respiratory muscles such as myasthenia gravis.
A nurse reviews the arterial blood gas (ABG) values of a client admitted with pneumonia: pH, 7.51; PaCO2, 28 mm Hg; PaO2, 70 mm Hg; and HCO3--, 24 mEq/L. What do these values indicate?
Respiratory alkalosis Explanation: A client with pneumonia may hyperventilate in an effort to increase oxygen intake. Hyperventilation leads to excess carbon dioxide (CO2) loss, which causes alkalosis — indicated by this client's elevated pH value. With respiratory alkalosis, the kidneys' bicarbonate (HCO3-) response is delayed, so the client's HCO3- level remains normal. The below-normal value for the partial pressure of arterial carbon dioxide (PaCO2) indicates CO2 loss and signals a respiratory component. Because the HCO3- level is normal, this imbalance has no metabolic component. Therefore, the client is experiencing respiratory alkalosis
A nurse reviews the arterial blood gas (ABG) values of a client admitted with pneumonia: pH, 7.51; PaCO2, 28 mm Hg; PaO2, 70 mm Hg; and HCO3--, 24 mEq/L. What do these values indicate?
Respiratory alkalosis Explanation: A client with pneumonia may hyperventilate in an effort to increase oxygen intake. Hyperventilation leads to excess carbon dioxide (CO2) loss, which causes alkalosis — indicated by this client's elevated pH value. With respiratory alkalosis, the kidneys' bicarbonate (HCO3-) response is delayed, so the client's HCO3- level remains normal. The below-normal value for the partial pressure of arterial carbon dioxide (PaCO2) indicates CO2 loss and signals a respiratory component. Because the HCO3- level is normal, this imbalance has no metabolic component. Therefore, the client is experiencing respiratory alkalosis.
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 Explanation: Respiratory alkalosis results from alveolar hyperventilation. It's marked by a decrease in PaCO2 to less than 35 mm Hg and an increase in blood pH over 7.45. Metabolic acidosis is marked by a decrease in HCO3? to less than 22 mEq/L, and a decrease in blood pH to less than 7.35. In respiratory acidosis, the pH is less than 7.35 and the PaCO2 is greater than 45 mm Hg. In metabolic alkalosis, the HCO3? is greater than 26 mEq/L and the pH is greater than 7.45.
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 Explanation: Ham (1,400 mg Na for 3 oz) and bacon (155 mg Na/slice) are high in sodium as is tomato juice (660 mg Na/¾ cup) and low fat cottage cheese (918 mg Na/cup). Packaged meals are high in sodium.
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. Normally, urine contains no protein, glucose, ketones, bilirubin, bacteria, casts, or crystals. Red blood cells should measure 0 to 3 per high-power field; white blood cells, 0 to 4 per high-power field. Urine should be clear, with color ranging from pale yellow to deep amber.
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?
bicarbonate-carbonic acid buffer system Explanation: The major chemical regulator of plasma pH is the bicarbonate-carbonic acid buffer system. The renin-angiotensin-aldosterone system regulates blood pressure. The sodium-potassium pump regulate homeostasis. The ADH-ANP buffer system regulates water balance in the body.
A client is taking spironolactone to control hypertension. The client's serum potassium level is 6 mEq/L. What is the nurse's priority during assessment?
electrocardiogram (ECG) results Explanation: Although changes in all these findings are seen in hyperkalemia, ECG results should take priority because changes can indicate potentially lethal arrhythmias such as ventricular fibrillation. It wouldn't be appropriate to assess the client's neuromuscular function, bowel sounds, or respiratory rate for effects of hyperkalemia.
A nurse evaluates a client's laboratory results. What is a factor that may be affecting an increase in serum osmolality?
free water loss Explanation: Osmolality measures the solute concentration per kilogram in blood and urine. Water loss in the serum would increase the solute concentration. Free water loss is a factor increasing serum osmolality. Diuretic use, overhydration, and hyponatremia are factors decreasing serum osmolality.
Fluid and electrolyte balance is maintained through the process of translocation. What specific process allows water to pass through a membrane from a dilute to a more concentrated area?
osmosis Explanation: Osmosis is the movement of water through a semipermeable membrane; one that allows some but not all substances in a solution to pass through from a diluted area to a more concentrated area. Filtration promotes the movement of fluid and some dissolved substances through a semipermeable membrane according to pressure differences. Evaporation is the process of converting water into a vapor. Active transport requires the energy source ATP to drive dissolved chemicals from an area of low concentration to an area of higher concentration; the opposite of passive diffusion.
A client is diagnosed with hypocalcemia and the nurse is teaching the client about symptoms. What symptom would the nurse include in the teaching?
tingling sensation in the fingers Explanation: Tingling or numbness in the fingers is a symptom of hypocalcemia. Flank pain, polyuria, and hypertension are symptoms of hypercalcemia.
