MS II Prep U Ch. 13 Fluid and Electrolyte Balance & Acid-Base Balance

The physician has prescribed a hypotonic IV solution for a patient. Which IV solution should the nurse administer?

0.45% sodium chloride Half-strength saline (0.45% sodium chloride) solution is frequently used as an IV hypotonic solution.

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 The major chemical regulator of plasma pH is the bicarbonate-carbonic acid buffer system. Therefore options A and C are incorrect. Option D does not exist, it is only a distractor for this question.

A client has been diagnosed with an intestinal obstruction and has a nasogastric tube set to low continuous suction. Which acid-base disturbance is this client at risk for developing?

Metabolic alkalosis Metabolic alkalosis is a clinical disturbance characterized by a high pH and a high plasma biacarbonate concentration. The most common cuase of metabolic alkalosis is vomiting or gastric suction with loss of hydrogen and choloride ions. Gastric fluid has an acid pH, and loss of this acidic fluid increases the alkalinity of body fluids.

Early signs of hypervolemia include

increased breathing effort and weight gain. 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 is to receive hypotonic IV solution in order to provide free water replacement. Which solution does the nurse anticipate administering?

0.45% NaCl 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.

Upon shift report, the nurse states the following laboratory values: pH, 7.44; PCO2, 30mmHg; and HCO3,21 mEq/L for a client with noted acid-base disturbances. Which acid-base imbalance do both nurses agree is the client's current state?

Compensated respiratory alkalosis The question states that the client has a history of acid-base disturbance. The nurse would first note that the pH has returned to close to normal indicating compensation. The nurse then assess the PCO2 (normal: 35 to 45 mm Hg) and HCO3 (normal: 22 to 27mEq/L) levels. In a respiratory condition, the pH and the PCO2 move in opposite direction; thus, the pH rises and the PCO2 drops (alkalosis) or vice versa (acidosis). In a metabolic condition, the pH and the bicarbonate move in the same direction; if the pH is low, the bicarbonate level will be low, also. In this client, the pH is at the high end of normal, indicating compensation and alkalosis. The PCO2 is low, indicating a respiratory condition (opposite direction of the pH).

A nurse is caring for an adult client with numerous draining wounds from gunshots. The client's pulse rate has increased from 100 to 130 beats per minute over the last hour. The nurse should further assess the client for which of the following?

Extracellular fluid volume deficit Fluid volume deficit (FVD) occurs when the loss extracellular fluid (ECF) volume exceeds the intake of fluid. FVD results from loss of body fluids and occurs more rapidly when coupled with decreased fluid intake. A cause of this loss is hemorrhage.

What foods can the nurse recommend for the patient with hypokalemia?

Fruits such as bananas and apricots Sources of potassium include fruit juices and bananas, melon, citrus fruits, fresh and frozen vegetables, lean meats, milk, and whole grains (Crawford & Harris, 2011b).

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. These losses are noted as unnoticeable and unmeasurable. Those with respiratory deficits and allergies may be only able to be outside for a limited period. Those with cardiovascular compromise may need to alternate outdoor activities with indoor rest

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 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 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 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.

Which of the following arterial blood gas results would be consistent with metabolic alkalosis?

Serum bicarbonate of 28 mEq/L Evaluation of arterial blood gases reveals a pH greater than 7.45 and a serum bicarbonate concentration greater than 26 mEq/L.

A client with respiratory acidosis is admitted to the intensive care unit for close observation. The nurse should stay alert for which complication associated with respiratory acidosis?

Shock Complications of respiratory acidosis include shock and cardiac arrest. Stroke and hyperglycemia aren't associated with respiratory acidosis. Seizures may complicate respiratory alkalosis, not respiratory acidosis.

A client with emphysema is at a greater risk for developing which acid-base imbalance?

chronic respiratory acidosis 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.

The nurse is caring for a client diagnosed with bulimia. The client is being treated for a serum potassium concentration of 2.9 mEq/L (2.9 mmol/L). Which statement made by the client indicates the need for further teaching?

"I can use laxatives and enemas but only once a week." The client is experiencing hypokalemia, most likely due to the diagnosis of bulimia. Hypokalemia is defined as a serum potassium concentration <3.5 mEq/L (3.5 mmol/L), and usually indicates a deficit in total potassium stores. Clients diagnosed with bulimia frequently suffer increased potassium loss through self-induced vomiting and misuse of laxatives, diuretics, and enemas; thus, the client should avoid laxatives and enemas. Prevention measures may involve encouraging the client at risk to eat foods rich in potassium (when the diet allows), including fruit juices and bananas, melon, citrus fruits, fresh and frozen vegetables, lean meats, milk, and whole grains. If the hypokalemia is caused by abuse of laxatives or diuretics, client education may help alleviate the problem.

Which solution is hypotonic?

0.45% NaCl Half-strength saline is hypotonic. Lactated Ringer solution and normal saline (0.9% NaCl) are isotonic. A 5% NaCl solution is hypertonic.

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 A 2-lb weight gain in 24 hours indicates that the client is retaining 1L of fluid.

A client has chronic hyponatremia, which requires weekly blood labs to keep prevent the client lapsing into convulsions or a coma. What is the level of serum sodium below which convulsions or coma can occur?

135 mEq/L When the level dips below 135 mEq/L, there is hyponatremia. Manifestations include 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. A level of 147 mEq/L would indicate hypernatremia, which is serum sodium level above 145 mEq/L. Normal serum concentration level ranges from 135 to 145 mEq/L.

Below which serum sodium concentration might convulsions or coma occur?

135 mEq/L (135 mmol/L) Normal serum concentration level ranges from 135 to 145 mEq/L (135-145 mmol/L). When the level dips below 135 mEq/L (135 mmol/L), hyponatremia occurs. Manifestations of hyponatremia include 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. Values of 140, 142, and 145 mEq/L (mmol/L) are within the normal range.

The nurse is caring for a client in the intensive care unit (ICU) following a near-drowning event in saltwater. The client is restless, lethargic, and demonstrating tremors. Additional assessment findings include swollen and dry tongue, flushed skin, and peripheral edema. The nurse anticipates that the client's serum sodium value would be

155 mEq/L (155 mmol/L) The client is experiencing signs and symptoms (S/S) of hypernatremia. Hypernatremia is a serum sodium concentration >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 of hypernatremia include thirst, elevated body temperature, swollen and 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. p. 246.

A client weighing 160 pounds 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 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 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. 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 patient is admitted with a diagnosis of renal failure. The patient complains of "stomach distress" and describes ingesting several antacid tablets over the past 2 days. Blood pressure is 110/70 mm Hg, face is flushed, and the patient is experiencing generalized weakness. Which is the most likely magnesium level associated with the symptoms the patient is having?

5 mEq/L Magnesium excess (>2.7 mEq/L) is associated with the following symptoms: flushing, hypotension, muscle weakness, drowsiness, hypoactive reflexes, depressed respirations, and cardiac arrest. The respiratory center is depressed when serum magnesium levels exceed 10 mEq/L (5 mmol/L). This is not present in this patient, so the magnesium level is unlikely to be 11 mEq/L. Coma, atrioventricular heart block, and cardiac arrest can occur when the serum magnesium level is greatly elevated and not treated.

A client experiencing a severe anxiety attack and hyperventilating presents to the emergency department. The nurse would expect the client's pH value to be

7.50 The patient is experiencing respiratory alkalosis. Respiratory alkalosis is a clinical condition in which the arterial pH is >7.45 and the PaCO2 is <38 mm Hg. Respiratory alkalosis is always caused by hyperventilation, which causes excessive "blowing off" of CO2 and, hence, a decrease in the plasma carbonic acid concentration. Causes include extreme anxiety, hypoxemia, early phase of salicylate intoxication, gram-negative bacteremia, and inappropriate ventilator settings.

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 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 patients will not likely have an electrolyte imbalance. Myocardial infarction patients will occasionally have electrolyte imbalance, but this is the exception rather than the rule.

A patient's serum sodium concentration is within the normal range. What should the nurse estimate the serum osmolality to be?

275-300 mOsm/kg In healthy adults, normal serum osmolality is 270 to 300 mOsm/kg (Crawford & Harris, 2011c).

The nurse is caring for a patient with a diagnosis of hyponatremia. What nursing intervention is appropriate to include in the plan of care for this patient? (Select all that apply.)

Assessing for symptoms of nausea and malaise Monitoring neurologic status Restricting tap water intake For patients at risk, the nurse closely laboratory values (i.e., sodium) and be alert for GI manifestations such as anorexia, nausea, vomiting, and abdominal cramping. The nurse must be alert for central nervous system changes, such as lethargy, confusion, muscle twitching, and seizures. Neurologic signs are associated with very low sodium levels that have fallen rapidly because of fluid overloading. For a patient with abnormal losses of sodium who can consume a general diet, the nurse encourages foods and fluids with high sodium content to control hyponatremia. For example, broth made with one beef cube contains approximately 900 mg of sodium; 8 oz of tomato juice contains approximately 700 mg of sodium. If the primary problem is water retention, it is safer to restrict fluid intake than to administer sodium.

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. 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.

The nurse is caring for a client with laboratory values indicating dehydration. Which clinical symptom is consistent with the dehydration?

Dark, concentrated urine Dehydration indicates a fluid volume deficit. Dark, concentrated urine indicates a lack of fluid volume. Adding more fluid would dilute the urine. The other options indicate fluid excess.

A client has a respiratory rate of 38 breaths/min. What effect does breathing faster have on arterial pH level?

Increases arterial pH 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 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. 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.

The nurse monitors a patient who is being evaluated for hyperkalemia. She is aware that ECG changes and serum potassium levels are diagnostic. Which of the following are the earliest changes that the nurse should report?

K+ = 7 mEq/L; peaked T waves The earliest changes occur when the serum potassium level is 7 mEq/L. Cardiac tracings include peaked and narrow T waves, ST segment depression and a shortened QT interval. Refer to Figure 4-6.

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 rise in pH?

The lungs are not able to blow off carbon dioxide. 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 nurse is caring for a client in acute renal failure. The nurse should expect hypertonic glucose, insulin infusions, and sodium bicarbonate to be used to treat:

hyperkalemia. Hyperkalemia is a common complication of acute renal failure. It's life-threatening if immediate action isn't taken to reverse it. Administering glucose and regular insulin, with sodium bicarbonate if necessary, can temporarily prevent cardiac arrest by moving potassium into the cells and temporarily reducing serum potassium levels. Hypernatremia, hypokalemia, and hypercalcemia don't usually occur with acute renal failure and aren't treated with glucose, insulin, or sodium bicarbonate.

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 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.

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 Arterial blood gas (ABG) results are the main tool for measuring blood pH, CO2 content (PaCO2), and bicarbonate. An acid-base imbalance may accompany a fluid and electrolyte imbalance. PaO2 and PO2 are not indications of acid-base imbalance. Carbonic acid levels are not shown in an ABG.

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 Arterial blood gas (ABG) results are the main tool for measuring blood pH, CO2 content (PaCO2), and bicarbonate. An acid-base imbalance may accompany a fluid and electrolyte imbalance. PaO2 and PO2 are not indications of acid-base imbalance. Carbonic acid levels are not shown in an ABG.

A 73-year-old female patient with cirrhosis of the liver is evaluated for clinical manifestations of FVE. Which of the following signs are consistent with that diagnosis? Select all that apply.

Blood pressure of 140/110 Hematocrit level of 32% BUN of 8 mg/dL Crackles The blood pressure is increased with FVE. Crackles are abnormal lung sounds found in fluid retention. Hematocrit and BUN may be decreased due to plasma dilution

A patient complains of 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 patient's laboratory work has returned?

Calcium 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.

Which findings indicate that a client has developed water intoxication secondary to treatment for diabetes insipidus?

Confusion and seizures 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.

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 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. Therefore, options A, C, and D are incorrect.

Which of the following is a clinical manifestation of fluid volume excess (FVE)? Select all that apply.

Distended neck veins Crackles in the lung fields Shortness of breath Clinical manifestations of FVE include distended neck veins, crackles in the lung fields, shortness of breath, increased blood pressure, and tachycardia.

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 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 laboratory result does the nurse identify as a direct result of the client's hypovolemic status with hemoconcentration?

Elevated hematocrit level When hemoconcentration occurs due to a hypovolemic state, a high ratio of blood components in relation to watery plasma occurs, thus causing an elevated hematocrit level. A high white blood cell count and urine specific gravity is also noted. Other causes of an abnormal potassium level may be present.

Before seeing a newly assigned client with respiratory alkalosis, a nurse quickly reviews the client's medical history. Which condition is a predisposing factor for respiratory alkalosis?

Extreme anxiety Extreme anxiety may lead to respiratory alkalosis by causing hyperventilation, which results in excessive carbon dioxide (CO2) loss. Other conditions that may set the stage for respiratory alkalosis include fever, heart failure, injury to the brain's respiratory center, overventilation with a mechanical ventilator, pulmonary embolism, and early salicylate intoxication. Type 1 diabetes may lead to diabetic ketoacidosis; the deep, rapid respirations occurring in this disorder (Kussmaul's respirations) don't cause excessive CO2 loss. Myasthenia gravis and opioid overdose suppress the respiratory drive, causing CO2 retention, not CO2 loss; this may lead to respiratory acidosis, not alkalosis.

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 The normal reference range for serum calcium is 9 to 11 mg/dl. A serum calcium level of 12 mg/dl clearly indicates hypercalcemia. The client's other laboratory findings are within their normal ranges, so the client doesn't have hypernatremia, hypochloremia, or hypokalemia. pg 260

A client presents with fatigue, nausea, vomiting, muscle weakness, and leg cramps. Laboratory values are as follows: Na + 147 mEq/L K + 3.0 mEq/L Cl - 112 mEq/L Mg ++ 2.3 mg/dL Ca ++ 1.5 mg/dL

Hypokalemia Potassium is the major intracellular electrolyte. Hypokalemia (below 3.5 mEq/L) usually indicates a deficit in total potassium stores. Potassium deficiency can result in derangements in physiology. Clinical signs include fatigue, anorexia, nausea, vomiting, muscles weakness, leg cramps, decreased bowel motility, and paresthesias.

Oral intake is controlled by the thirst center, located in which of the following cerebral areas?

Hypothalamus Oral intake is controlled by the thirst center located in the hypothalamus. The thirst center is not located in the cerebellum, brainstem, or thalamus.

Which could be a potential cause of respiratory acidosis?

Hypoventilation Respiratory acidosis is always due to inadequate excretion of CO2, with inadequate ventilation, resulting in elevated plasma CO concentration, which causes increased levels of carbonic acid. In addition to an elevated PaCO2, hypoventilation usually causes a decrease in PaO2.

A client with a magnesium concentration of 2.6 mEq/L (1.3 mmol/L) is being treated on a medical-surgical unit. Which treatment should the nurse anticipate will be used?

Intravenous furosemide (Lasix) The nurse should anticipate the administration of furosemide (Lasix) for the treatment of hypermagnesemia. Administration of loop diuretics (e.g., furosemide) and sodium chloride or lactated Ringer intravenous solution enhances magnesium excretion in clients with adequate renal function. Fluid restriction is contraindicated. The client should be encouraged to increase fluids to promote the excretion magnesium through the urine. Magnesium oxide (MagOx) is contraindicated because it would further elevate the client's serum magnesium concentration. In acute emergencies, when the magnesium concentration is severely elevated, hemodialysis with a magnesium-free dialysate can reduce the serum magnesium to a safe concentration within hours.

A physician orders an isotonic I.V. solution for a client. Which solution should the nurse plan to administer?

Lactated Ringer's solution Lactated Ringer's solution, with an osmolality of approximately 273 mOsm/L, is isotonic. The nurse shouldn't give half-normal saline solution because it's hypotonic, with an osmolality of 154 mOsm/L. Giving 5% dextrose and normal saline solution (with an osmolality of 559 mOsm/L) or 10% dextrose in water (with an osmolality of 505 mOsm/L) also would be incorrect because these solutions are hypertonic.

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 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.

The nurse is caring for a client undergoing alcohol withdrawal. Which serum laboratory value should the nurse monitor most closely?

Magnesium 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 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

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 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. Anion gap is not used to check for respiratory alkalosis, metabolic alkalosis, or respiratory acidosis.

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 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 is experiencing edema in the tissue. The nurse is correct in anticipating which tonicity of intravenous fluid?

No intravenous solution There are three types (tonicity) of intravenous fluids, which are isotonic, hypotonic, and hypertonic solutions. By process of osmosis and diffusion, solutes are moved through the body. A hypertonic solution is used to pull water back in to circulation as a hypertonic solution has more particles than the body's water. An isotonic solution is the same concentration as the body's water and is used as an intravenous volume expander. A hypotonic solution has fewer particles than the body's water thus shifting water from the vascular space to the tissue.

A 64-year-old client is brought in to the clinic feeling thirsty with dry, sticky mucous membranes; decreased urine output; fever; a rough tongue; and is lethargic. 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. The symptoms and the high level of serum sodium suggest hypernatremia, (excess of sodium). It is necessary to restrict sodium intake. Salt tablets and sodium chloride IV can only worsen this condition but may be required in hyponatremia (sodium deficit). Hypotonic solution IV may be a part of the treatment but not along with the salt tablets

Which electrolyte is a major cation in body fluid?

Potassium Potassium is a major cation that affects cardiac muscle functioning. Chloride, bicarbonate, and phosphate are anions.

A client with pancreatic cancer has the following blood chemistry profile: Glucose, fasting: 204 mg/dl; blood urea nitrogen (BUN): 12 mg/dl; Creatinine: 0.9 mg/dl; Sodium: 136 mEq/L; Potassium: 2.2 mEq/L; Chloride: 99 mEq/L; CO2: 33 mEq/L. Which result should the nurse identify as critical and report immediately?

Potassium The nurse should identify potassium: 2.2 mEq/L as critical because a normal potassium level is 3.8 to 5.5 mEq/L. Severe hypokalemia can cause cardiac and respiratory arrest, possibly leading to death. Hypokalemia also depresses the release of insulin and results in glucose intolerance. The glucose level is above normal (normal is 75 to 110 mg/dl) and the chloride level is a bit low (normal is 100 to 110 mEq/L). Although these levels should be reported, neither is life-threatening. The BUN (normal is 8 to 26 mg/dl) and creatinine (normal is 0.8 to 1.4 mg/dl) are within normal range.

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. Respiratory acidosis is associated with hypoventilation; in this client, hypoventilation suggests intake of a drug that has suppressed the brain's respiratory center. Therefore, the nurse should assume the client has respiratory depression and should prepare to assist with ventilation. After the client's respiratory function has been stabilized, the nurse can safely monitor the heart rhythm, prepare for gastric lavage, and obtain a urine specimen for drug screening.

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 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 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 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.

The nurse is participating in the care of a client who had a peripherally inserted central catheter (PICC) placed in the right arm. After catheter placement, the nurse should complete which action?

Send the client for a chest x-ray. A chest x-ray is needed to confirm the placement of catheter tip before initiating ordered infusions. Consent should be obtained before, not after, the procedure. No BPs should be taken on the extremity where the catheter is placed.

A client with nausea, vomiting, and abdominal cramps and distention is admitted to the health care facility. Which test result is most significant?

Serum potassium level of 3 mEq/L A serum potassium level of 3 mEq/L is below normal, indicating hypokalemia. Because hypokalemia may cause cardiac arrhythmias and asystole, it's the most significant finding. In a client with a potential fluid volume imbalance, such as from vomiting, the other options are expected but none are as life-threatening as hypokalemia. A BUN level of 29 mg/dl indicates slight dehydration. A serum sodium level of 132 mEq/L is slightly below normal but not life-threatening. A urine specific gravity of 1.025 is normal.

A client is diagnosed with syndrome of inappropriate antidiuretic hormone (SIADH). The nurse should anticipate which laboratory test result?

Serum sodium level of 124 mEq/L In SIADH, the posterior pituitary gland produces excess antidiuretic hormone (vasopressin), which decreases water excretion by the kidneys. This, in turn, reduces the serum sodium level, causing hyponatremia, as indicated by a serum sodium level of 124 mEq/L. In SIADH, the serum creatinine level isn't affected by the client's fluid status and remains within normal limits. A hematocrit of 52% and a BUN level of 8.6 mg/dl are elevated. Typically, the hematocrit and BUN level decrease.

Which medication does the nurse anticipate administering to antagonize the effects of potassium on the heart for a patient in severe metabolic acidosis?

Sodium bicarbonate IV administration of sodium bicarbonate may be necessary in severe metabolic acidosis to alkalinize the plasma, shift potassium into the cells, and furnish sodium to antagonize the cardiac effects of potassium (Crawford & Harris, 2011b).

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 Hypernatremia (normal serum sodium is 135 to 145 mEq/L) is consistent with increased fluid loss and dehydration in diabetes insipidus.

To compensate for decreased fluid volume (hypovolemia), the nurse can anticipate which response by the body?

Tachycardia Fluid volume deficit, or hypovolemia, occurs when the loss of extracellular fluid exceeds the intake of fluid. Clinical signs include oliguia, rapid heart rate, vasoconstriction, cool and clammy skin, and muscle weakness. The nurse monitors for rapid, weak pulse and orthostatic hypotension.

A nurse is reviewing a report of a client's routine urinalysis. Which value requires further investigation?

Urine pH of 3.0 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 client was admitted to the hospital unit after 2 days of vomiting and diarrhea. The client's spouse became alarmed when the client demonstrated confusion and elevated temperature, and reported "dry mouth." The nurse suspects the client is experiencing which condition?

dehydration Dehydration results when the volume of body fluid is significantly reduced in both extracellular and intracellular compartments. In dehydration, all fluid compartments have decreased volumes; in hypovolemia, only blood volume is low. The most common fluid imbalance in older adults is dehydration. Hypervolemia is caused by fluid intake that exceeds fluid loss, such as from excessive oral intake or rapid IV infusion of fluid. Early signs of hypervolemia are weight gain, elevated BP, and increased breathing effort. Hypercalcemia occurs when the serum calcium level is higher than normal. Some of its signs include tingling in the extremities and the area around the mouth (circumoral paresthesia) and muscle and abdominal cramps. Hyperkalemia is an excess of potassium in the blood. Symptoms include diarrhea, nausea, muscle weakness, paresthesias, and cardiac dysrhythmias.

An elderly client takes 40 mg of Lasix twice a day. Which electrolyte imbalance is the most serious adverse effect of diuretic use?

hypokalemia 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.

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 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.

Following a unilateral adrenalectomy, a nurse should assess for hyperkalemia as indicated by:

muscle weakness Muscle weakness, bradycardia, nausea, diarrhea, and paresthesia of the hands, feet, tongue, and face are findings associated with hyperkalemia, which is transient and results from transient hypoaldosteronism when the adenoma is removed. Tremors, diaphoresis, and constipation aren't seen in hyperkalemia.

To confirm an acid-base imbalance, it is necessary to assess which findings from a client's arterial blood gas (ABG) results? Select all that apply.

pH PaCO2 HCO3 Arterial blood gas (ABG) results are the main tool for measuring blood pH, CO2 content (PaCO2), and bicarbonate (HCO3). The two types of acid-base imbalances are acidosis and alkalosis. pg 267

When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis?

pH 7.48 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.

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 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 with Guillain-Barré syndrome develops respiratory acidosis as a result of reduced alveolar ventilation. Which combination of arterial blood gas (ABG) values confirms respiratory acidosis?

pH, 7.25; PaCO2 50 mm Hg In respiratory acidosis, ABG analysis reveals an arterial pH below 7.35 and partial pressure of arterial carbon dioxide (PaCO2) above 45 mm Hg. Therefore, the combination of a pH value of 7.25 and a PaCO2 value of 50 mm Hg confirms respiratory acidosis. A pH value of 7.5 with a PaCO2 value of 30 mm Hg indicates respiratory alkalosis. A ph value of 7.40 with a PaCO2 value of 35 mm Hg and a pH value of 7.35 with a PaCO2 value of 40 mm Hg represent normal ABG values, reflecting normal gas exchange in the lungs.

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. 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. These ABG values wouldn't occur in metabolic acidosis, respiratory acidosis, or metabolic alkalosis.

A client has been admitted to the hospital unit with signs and symptoms of hypovolemia; however, the client has not lost weight. The client exhibits a localized enlargement of her abdomen. What condition could the client be presenting?

third-spacing Third-spacing describes the translocation of fluid from the intravascular or intercellular space to tissue compartments, where it becomes trapped and useless. The client manifests signs and symptoms of hypovolemia with the exception of weight loss. There may be signs of localized enlargement of organ cavities (such as the abdomen) if they fill with fluid, a condition referred to as ascites. Pitting edema occurs when indentations remain in the skin after compression. Anascara is another term for generalized edema, or brawny edema, in which the interstitial spaces fill with fluid. Hypovolemia (fluid volume deficit) refers to a low volume of extracellular fluid.