Chapter 10 Prep U Exam 2
The physician has prescribed a hypotonic IV solution for a patient. Which IV solution should the nurse administer?
0.45% sodium chloride
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 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.
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 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.
To evaluate a client for hypoxia, the physician is most likely to order which laboratory test?
ABGs 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.
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 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.
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 lactated ringers IV 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.
The physician has prescribed a hypotonic IV solution for a patient. Which IV solution should the nurse administer?
Half-strength saline (0.45% sodium chloride) solution is frequently used as an IV hypotonic solution.
An elderly client takes 40 mg of furosemide 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 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.
A client presents with muscle weakness, tremors, slow muscle movements, and vertigo. The following are the client's laboratory values: Sodium 134 mEq/L (134 mmol/L)Potassium 3.2 mEq/L (3.2 mmol/L)Chloride 111 mEq/L (111 mmol/L)Magnesium 1.1 mg/dL (0.45 mmol/L)Calcium 8.4 mg/dL (2.1 mmol/L)
Magnesium, the second most abundant intracellular cation, The most common cause of this imbalance is loss in the gastrointestinal tract. Hypomagnesemia is a value less than 1.3 mg/dL (0.45 mmol/L). Signs and symptoms include muscle weakness, tremors, irregular movements, tetany, vertigo, focal seizures, and positive Chvostek's and Trousseau's signs.
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 bicarbonate concentration. The most common cause of metabolic alkalosis is vomiting or gastric suction with loss of hydrogen and chloride ions. Gastric fluid has an acid pH, and loss of this acidic fluid increases the alkalinity of body fluids.
Upon shift report, the nurse states the following laboratory values: pH, 7.44; PCO2, 30 mm Hg; 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?
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 27 mEq/L) levels. In a respiratory condition, the pH and the PCO2 move in opposite directions; 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 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.
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
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.
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. Anasarca 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.
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 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.
checking the effectiveness of mechanical ventilation
check ABGs
A client hospitalized for treatment of a pulmonary embolism develops respiratory alkalosis. Which clinical findings commonly accompany respiratory alkalosis?
lightheadedness and paresthesia 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.
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.
At which serum sodium concentration might convulsions or coma occur?
130 mEq/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.
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 laxities, 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.
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.
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.
