Exam 1 - Chapter 4
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 137 mEq/L Potassium level of 3.8 mEq/L Sodium level of 150 mEq/L Potassium level of 6 mEq/L
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.
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? 4.5 mEq/L 5.5 mEq/L 2.5 mEq/L 3.5 mEq/L
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.
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? Myasthenia gravis Type 1 diabetes mellitus Extreme anxiety Opioid overdose
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 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.
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? Respiratory acidosis Respiratory alkalosis Metabolic acidosis Metabolic alkalosis
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.
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? Metabolic acidosis Metabolic alkalosis Respiratory acidosis Respiratory alkalosis
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 patient with a history of poorly controlled type 1 diabetes has begun displaying the characteristic signs and symptoms of diabetic nephropathy. The patient's nurse recognizes that the patient is at risk of disruptions to fluid balance. What role do the kidneys play in the maintenance of normal fluid balance? Secreting or withholding antidiuretic hormone in response to extracellular fluid volume Selectively retaining needed substances and excreting waste products Synthesizing and releasing angiotensin in cases of fluid volume deficit Maintaining the correct concentration of H+ ions in the blood
Selectively retaining needed substances and excreting waste products Major functions of the kidneys in maintaining normal fluid balance include regulation of extracellular fluid (ECF) volume and osmolality by selective retention and excretion of body fluids and regulation of electrolyte levels in the ECF by selective retention of needed substances and excretion of unneeded substances. Antidiuretic hormone (ADH) is secreted by the pituitary gland, and angiotensin is ultimately derived from the liver, not the kidneys. Concentration of H+ ions contributes the buffer action of the kidneys, not the maintenance of fluid balance.
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 filtration evaporation active transport
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.
When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis? HCO 21 mEq/L pH 7.48 PaCO 36 O saturation 95%
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.
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, 7.5; PaCO2 30 mm Hg pH, 7.40; PaCO2 35 mm Hg pH, 7.35; PaCO2 40 mm Hg pH, 7.25; PaCO2 50 mm Hg
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 patient with a diagnosis of thyroid cancer is postoperative day 1 following a total thyroidectomy in which her parathyroid gland was also removed. When assessing for related electrolyte imbalances, what question should the nurse ask the patient? "Do you feel like you're having heart palpitations where your heart feels like it skips a beat?" "How thirsty are you feeling right now?" "Are you feeling any tingling in your hands or around your mouth?" "How would you rate your energy level right now?"
"Are you feeling any tingling in your hands or around your mouth?" Removal of the parathyroid can precipitate hypocalcemia, which often results in tetany. Arrhythmias, increased thirst, and fatigue are not common assessment findings associated with low serum calcium.
To evaluate a client for hypoxia, the physician is most likely to order which laboratory test? Red blood cell count Sputum culture Total hemoglobin Arterial blood gas (ABG) analysis
Arterial blood gas (ABG) analysis 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 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? PaO2 PO2 Carbonic acid Bicarbonate
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.
Oral intake is controlled by the thirst center, located in which of the following cerebral areas? Hypothalamus Cerebellum Brainstem Thalamus
Hypothalamus
A client has a respiratory rate of 38 breaths/min. What effect does breathing faster have on arterial pH level? No effect Increases arterial pH Decreases arterial pH Provides long-term pH regulation
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.
The nurse on a surgical unit is caring for a client recovering from recent surgery with the placement of a nasogastric tube to low continuous suction Which acid-base imbalance is most likely to occur? Respiratory alkalosis Metabolic alkalosis Respiratory acidosis Metabolic acidosis
Metabolic alkalosis Metabolic alkalosis results in increased plasma pH because of an accumulated base bicarbonate or decreased hydrogen ion concentration. Factors that increase base bicarbonate include excessive oral or parenteral use of bicarbonate-containing drugs, a rapid decrease in extracellular fluid volume and loss of hydrogen and chloride ions as with gastric suctioning. Acidotic states are from excess carbonic acid and hydrogen ions in the system. Respiratory alkalosis results from a carbonic acid deficit that occurs when rapid breathing releases more CO2 than necessary.
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? Metabolic acidosis Metabolic alkalosis Respiratory acidosis Respiratory alkalosis
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 with emphysema is at a greater risk for developing which acid-base imbalance? chronic respiratory acidosis metabolic alkalosis metabolic acidosis respiratory alkalosis
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.
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: 210 mOsm/kg. 230 mOsm/kg. 250 mOsm/kg. 280 mOsm/kg.
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 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 7.45 7.35 7.30
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 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 500 ml 1500 ml 1250 ml
1L A 2-lb weight gain in 24 hours indicates that the client is retaining 1L of fluid.
A client is to receive hypotonic IV solution in order to provide free water replacement. Which solution does the nurse anticipate administering? Lactated Ringer solution 0.45% NaCl 0.9% NaCl 5% NaCl
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.
The physician has prescribed a hypotonic IV solution for a patient. Which IV solution should the nurse administer? 0.45% sodium chloride 0.9% sodium chloride 5% glucose in water 5% glucose in normal saline solution
0.45% sodium chloride Half-strength saline (0.45% sodium chloride) solution is frequently used as an IV hypotonic solution.
Which is considered an isotonic solution? 0.9% normal saline Dextran in normal saline 0.45% normal saline 3% NaCl
0.9% normal saline An isotonic solution is 0.9% normal saline (NaCl). Dextran in normal saline is a colloid solution, 0.45% normal saline is a hypotonic solution, and 3% NaCl is a hypertonic solution.
The nurse knows which is the normal serum value for potassium? 135-145 mEq/L (135-145 mmol/L). 96-106 mEq/L (96-106 mmol/L). 3.5-5.0 mEq/L (3.5-5.0 mmol/L). 8.5-10.5 mg/dL (2.13-2.63 mmol/L).
135-145 mEq/L (135-145 mmol/L).
The actions of buffer systems allow the body to rapidly and effectively respond to alterations in the H+ concentration of body fluids. How do the kidneys primarily contribute to a stable balance between acids and bases? By regulating the combination of water and carbon dioxide, thus controlling levels of carbonic acid By selectively reabsorbing HCO3- ions, which in turn act as H+ ion receptors By regulating the ventilation rate and consequent blood levels of CO2 By controlling the process of erythropoiesis and consequent hemoglobin levels
By selectively reabsorbing HCO3- ions, which in turn act as H+ ion receptors The kidneys' role in the bicarbonate-carbonic acid buffer system is to reabsorb filtered bicarbonate. The bicarbonate ion acts as a H+ ion acceptor, and is responsible for buffering 90% of the hydrogen ions in blood. Hemoglobin is a minor contributor to buffering, and the kidneys regulate neither ventilation nor the combination of water with carbon dioxide.
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. Administer IV bicarbonate. Suction the client's airway.
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 a serum sodium concentration of 113 mEq/L (113 mmol/L). The nurse should monitor the client for the development of which condition? Confusion Headache Nausea Hallucinations
Confusion 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.
An adult client is brought in to the clinic feeling thirsty with dry, sticky mucous membranes; decreased urine output; fever; a rough tongue; and lethargy. The nurse reconciles the client's medication list and notes that salt tablets had been prescribed. What would the nurse do next? Continue to monitor client with another appointment. Be prepared to administer a lactated Ringer's IV. Be prepared to administer a sodium chloride IV. Consider sodium restriction with discontinuation of salt tablets.
Consider sodium restriction with discontinuation of salt tablets.
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. Increase the rate of the intravenous lactated Ringer solution. Change the lactated Ringer solution to 3% saline. Change the lactated Ringer solution to 2.5% dextrose.
Discontinue the intravenous lactated Ringer solution 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 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 caffeinated beverages to retain fluid. Drink carbonated beverages to help balance fluid volume. Drink water as an inexpensive way to meet fluid needs. Respond to thirst
Drink at least eight glasses of fluid each day. Drink water as an inexpensive way to meet fluid needs. Respond to thirst 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.
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? Hyperkalemia Hypocalcemia Hypokalemia Hypercalcemia
Hypercalemia The normal reference range for serum calcium is 8.6 to 10.2 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.
Which could be a potential cause of respiratory acidosis? Vomiting Hypoventilation Diarrhea Hyperventilation
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.
When caring for a client who has risk factors for fluid and electrolyte imbalances, which assessment finding is the highest priority for the nurse to follow up? Irregular heart rate Weight loss of 4 lb Mild confusion Blood pressure 96/53 mm Hg
Irregular heart rate Irregular heart rate may indicate a potentially life-threatening cardiac dysrhythmia. Potassium, magnesium, and calcium imbalances may cause dysrhythmias. Weight loss is a good indicator of the amount of fluid lost, confusion may occur with dehydration and hyponatremia, and blood pressure is slightly lower than normal (though not life threatening); in each case, following up on potential cardiac dysrhythmias is a higher priority.
A physician orders an isotonic I.V. solution for a client. Which solution should the nurse plan to administer? 5% dextrose and normal saline solution Lactated Ringer's solution Half-normal saline solution 10% dextrose in water
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.
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 Slurred speech Negative Chvostek sign Muscle weakness
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 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. Cool area around the insertion site Reddened area along the path of the vein Tender area around the insertion site Ecchymosis at the insertion site Rapid, shallow respirations
Reddened area along the path of the vein Tender area around the insertion site 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.
An elderly patient has developed Clostridium difficile-related diarrhea and been subsequently diagnosed with fluid volume deficit (FVD). The nurse providing care for this patient should anticipate: A decreased level of blood urea nitrogen (BUN) An increased level of serum potassium The administration of a hypertonic IV solution The administration of hypotonic or isotonic IV solution
The administration of hypotonic or isotonic IV solution FVD necessitates the administration of isotonic IV solutions (in hypotensive patients) or hypotonic solutions (in normotensive patients). FVD is associated with increased levels of BUN and hypokalemia, especially in patients whose losses are due to vomiting or diarrhea.
A nurse is reviewing a report of a client's routine urinalysis. Which value requires further investigation? Specific gravity of 1.02 Urine pH of 3.0 Absence of protein Absence of glucose
Urine pH of 3.0
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? passive osmosis free flow passive elimination active transport
active transport 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.
Following a unilateral adrenalectomy, a nurse should assess for hyperkalemia as indicated by: muscle weakness. tremors. diaphoresis. constipation.
muscle weakness. Muscle weakness; bradycardia; nausea; diarrhea; and paresthesia of the hands, feet, tongue, and face are findings associated with hyperkalemia, which results from transient hypoaldosteronism when the adenoma is removed. Tremors, diaphoresis, and constipation aren't seen in hyperkalemia.
