Fluid & Electrolytes II

A client has been placed on a ventilator. The physician has ordered that the ventilator be set to deliver a respiratory rate set of 28 breaths/min. The nurse questions the order, citing concerns about which acid-base problem? a. Acid deficit: alkalosis b. Base excess: alkalosis c. Acid excess: acidosis d. Base deficit: acidosis

ANS: A A ventilator set at too high a ventilation rate and/or too high a tidal volume will cause the client to lose too much carbon dioxide, leading to an acid deficit and respiratory alkalosis.

Which action does the nurse take first for the client who is admitted to the emergency department (ED) with a panic attack and whose blood gases indicate respiratory alkalosis? a. Encourage the client to take slow breaths b. Obtain a prescription for a fluid and electrolyte infusion c. Administer oxygen using ED standard orders d. Place an emergency cart close to the client's room

ANS: A Because respiratory alkalosis is caused by hyperventilation, the nurse's first action should be to assist the client in slowing the respiratory rate. Respiratory alkalosis is caused by hyperventilation; fluid and electrolyte replacement will not help correct hyperventilation. No evidence suggests that hypoxemia exists; therefore, oxygen is not needed at this time. Ongoing respiratory alkalosis may eventually cause fluid and electrolyte shifts requiring IV emergency drugs; however, slowing the breathing and rebreathing of CO2 are the priority interventions.

Which diet would the nurse recommend to the mother of a child who is having mild diarrhea? a. Rice, potatoes, yogurt, cereal, and cooked carrots b. Bananas, rice, applesauce, and toast c. Apple juice, hamburger, and salad d. Whatever the child would like to eat

ANS: A Bland but nutritious foods including complex carbohydrates (rice, wheat, potatoes, cereals), yogurt, cooked vegetables, and lean meats are recommended to prevent dehydration and hasten recovery. These foods used to be recommended for diarrhea (BRAT diet). These foods are easily tolerated, but the BRAT diet is low in energy, density, fat, and protein. Fatty foods, spicy foods, and foods high in simple sugars should be avoided. The child should be offered foods he or she likes but should not be encouraged to eat fatty foods, spicy foods, and foods high in simple sugars.

A 2-month-old breastfed infant is successfully rehydrated with oral rehydration solutions (ORS) for acute diarrhea. What instructions to the mother about breastfeeding should be included by the nurse? A. Continue breastfeeding. B. Stop breastfeeding until breast milk is cultured. C. Stop breastfeeding until diarrhea is absent for 24 hours. D. Express breast milk and dilute with sterile water before feeding.

ANS: A Breastfeeding should continue. Culturing the breast milk is not necessary. Breastfeeding can continue along with ORS to replace the continuing fluid loss from the diarrhea. Breast milk should not be diluted.

A client has mild acidosis but after a day has not compensated for it. Which action by the nurse is best? a. Review the client's daily hemoglobin and hematocrit. b. Ask the laboratory to rerun today's arterial blood gases. c. Document the finding and notify the physician. d. Apply 2 L of oxygen via nasal cannula.

ANS: A Hemoglobin is part of the buffering system. Low hemoglobin affects acid-base balance by decreasing the body's ability to compensate for mild acidosis. Rerunning the specimen would take time and might require another sample. The nurse may need to notify the physician but would need more information to report, such as hemoglobin and hematocrit values. Adding 2 liters of oxygen would not help the client as much as he or she would be helped if the cause of the refractory acidosis was determined.

The nurse is caring for a critically ill client with septic shock. The serum lactate level is 6.2. For which acid-base disturbance should the nurse assess? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis

ANS: A Increased lactate levels are associated with hypoxia and metabolic acidosis secondary to anaerobic metabolism. Metabolic alkalosis is related to bicarbonate therapy, diuretic use, vomiting, and nasogastric suction. Respiratory acidosis is caused by CO2 retention and impaired pulmonary function, which is inconsistent with elevated lactate levels. Respiratory alkalosis is caused by excessive loss of CO2 through hyperventilation, inconsistent with elevated lactate levels.

What is the best response for the nurse to give a parent about contacting the physician regarding an infant with diarrhea? a. "Call your pediatrician if the infant has not had a wet diaper for 6 hours." b. "The pediatrician should be contacted if the infant has two loose stools in an 8-hour period." c. "Call the doctor immediately if the infant has a temperature greater than 100° F." d. "Notify the pediatrician if the infant naps more than 2 hours."

ANS: A No urine output in 6 hours needs to be reported because it indicates dehydration. Two loose stools in 8 hours is not a serious concern. If blood is obvious in the stool or the frequency increases to one bowel movement every hour for more than 8 hours, the physician should be notified. A fever greater than 101° F should be reported to the infant's physician. It is normal for the infant who is not ill to nap for 2 hours. The infant who is ill may nap longer than the typical amount.

A client has moderate acidosis. Which assessment does the nurse perform first? a. Take the client's pulse and blood pressure, and analyze the electrocardiogram (ECG) strip. b. Assess respiratory rate and depth and work of breathing. c. Perform assessments of musculoskeletal strength. d. Determine whether the client is awake, alert, and oriented.

ANS: A Priority assessments for the client with acidosis relate to the cardiovascular system. Acidosis can lead to lethal cardiac dysrhythmias

The hand grasps of a client with acidosis have diminished since the previous assessment 1 hour ago. What action does the nurse take next? a. Assess client's rate, rhythm, and depth of respiration. b. Measure the client's pulse and blood pressure. c. Document findings and continue to monitor. d. Notify the physician as soon as possible.

ANS: A Progressive skeletal muscle weakness is associated with increasing severity of acidosis. Muscle weakness can lead to severe respiratory insufficiency. Acidosis does lead to dysrhythmias (due to hyperkalemia) but these would best be assessed with cardiac monitoring. Findings should be documented, but simply continuing to monitor is not sufficient. Before notifying the physician, the nurse needs to have more data to report.

A new nurse graduate is caring for a postoperative client with the following arterial blood gas values: pH, 7.30; PaCO2, 60 mm Hg; PaO2, 80 mm Hg; bicarbonate, 24 mEq/L; and O2 saturation, 96%. Which of these actions by the new graduate is indicated? a. Encourage the client to use the incentive spirometer and cough. b. Administer oxygen by nasal cannula. c. Request a prescription for sodium bicarbonate from the health care provider

ANS: A Respiratory acidosis is caused by CO2 retention and impaired chest expansion secondary to anesthesia. The nurse takes steps to promote CO2 elimination, including maintaining a patent airway and expanding the lungs through breathing techniques. O2 is not indicated because PaO2 and oxygen saturation are within the normal range. Sodium bicarbonate is not indicated because the bicarbonate level is in the normal range; promoting excretion of respiratory acids is the priority in respiratory acidosis. Postanesthesia, the client will need interventions related to promoting CO2 elimination or the client may progress to a state of somnolence and unresponsiveness.

A morbidly obese client has chosen gastric bypass surgery to promote weight loss. The nurse plans to teach the client about the need to perform monitoring to detect what disturbance consistent with rapid weight loss associated with this procedure? a. Ketosis b. Hypoxemia c. Urinary retention d. Insufficient ventilation

ANS: A Starvation, fasting, or following a strict calorie-reduced diet with rapid weight loss contributes to ketone formation and metabolic acidosis. Weight loss should decrease the work of breathing and improve hypoxemia, if present, as well as hypoventilation. Urinary retention does not occur in acid-base imbalance.

The parents of a child with acid-base imbalance ask the nurse about mechanisms that regulate acid-base balance. Which statement by the nurse accurately explains the mechanisms regulating acid-base balance in children? a. The respiratory, renal, and chemical-buffering systems b. The kidneys balance acid; the lungs balance base c. The cardiovascular and integumentary systems d. The skin, kidney, and endocrine systems

ANS: A The acid-base system is regulated by chemical buffering, respiratory control of carbon dioxide, and renal regulation of bicarbonate and secretion of hydrogen ions. Both the kidneys and the lungs, along with the buffering system, contribute to acid-base balance. Neither system regulates acid or base balances exclusively. The cardiovascular and integumentary systems are not part of acid-base regulation in the body. Chemical buffers, the lungs, and the kidneys work together to keep the blood pH within normal range.

Which action is the primary concern in the treatment plan for a child with persistent vomiting? a. Detecting the cause of vomiting b. Preventing metabolic acidosis c. Positioning the child to prevent further vomiting d. Recording intake and output

ANS: A The primary focus of managing vomiting is detection of the cause and then treatment of the cause. Metabolic alkalosis results from persistent vomiting. Prevention of complications is the secondary focus of treatment. The child with persistent vomiting should be positioned upright or side-lying to prevent aspiration. Recording intake and output is a nursing intervention, but it is not the primary focus of treatment.

Which response is an example of compensation for an acid-base imbalance? a. Increase in the rate and depth of respirations when exercising b. Increased urinary output when blood pressure increases during exercise c. Increased thirst when spending time in an excessively dry environment d. Increased release of acids from kidneys during exacerbation of chronic obstructive pulmonary disease (COPD)

ANS: A The respiratory system increases its activity by blowing off excess carbon dioxide. This occurs as a result of the occurrence of lactic acidosis in skeletal muscle, when blood flow and oxygenation are insufficient to meet the increased demand for oxygen (oxygen debt) created during increased skeletal muscle metabolism. The other three options are not compensatory mechanisms for acid-base imbalances.

A client has the following arterial blood gases (ABGs): pH 7.30, HCO3- 22 mEq/L, PCO2 55 mm Hg, PO2 86 mm Hg. Which intervention by the nurse takes priority? a. Assessing the airway b. Administering bronchodilators c. Administering mucolytics d. Providing oxygen

ANS: A All interventions are important for clients with respiratory acidosis; this is indicated by the ABGs. However, the priority is assessing and maintaining an airway. Without a patent airway, other interventions will not be helpful.

A nurse evaluates a client's arterial blood gas values (ABGs): pH 7.30, PaO2 86 mm Hg, PaCO2 55 mm Hg, and HCO3- 22 mEq/L. Which intervention should the nurse implement first? a. Assess the airway. b. Administer prescribed bronchodilators. c. Provide oxygen. d. Administer prescribed mucolytics.

ANS: A All interventions are important for clients with respiratory acidosis; this is indicated by the ABGs. However, the priority is assessing and maintaining an airway. Without a patent airway, other interventions will not be helpful.

In a client with less than the normal amount of bicarbonate in the blood and other extracellular fluids, what response does the nurse anticipate? a. Increased risk for acidosis b. Decreased risk for acidosis c. Increased risk for alkalosis d. Decreased risk for alkalosis

ANS: A Bicarbonate (H2CO3-) is a weak base with an overall negative charge. When hydrogen ions are present in slight or mild excess (mild acidosis), bicarbonate can buffer or absorb the excess hydrogen ions, reducing the hydrogen ion concentration and bringing the pH back up to normal. If the total body bicarbonate concentration is low, especially in the blood, the action of buffering or absorbing excess hydrogen ions is reduced, and the person is at increased risk for acidosis.

A postoperative client received six units of packed red blood cells (PRBCs) for intraoperative blood loss. The nurse monitors the client for which acid-base imbalance? a. Metabolic alkalosis b. Metabolic acidosis c. Respiratory alkalosis d. Respiratory acidosis

ANS: A Citrate is a substance used as a preservative in blood products. It is not only a base, it is also a precursor for bicarbonate (bicarbonate can be formed from citrate). Rapid administration of blood products can cause metabolic alkalosis by infusing large amounts of citrate intravenously. Although this problem is more likely to occur with administration of whole blood or blood plasma, multiple transfusions with packed red cells can also result in excessive amounts of citrate being received by the client.

A nurse assesses a client who is experiencing an acid-base imbalance. The client's arterial blood gas values are pH 7.34, PaO2 88 mm Hg, PaCO2 38 mm Hg, and HCO3- 19 mEq/L. Which assessment should the nurse perform first? a. Cardiac rate and rhythm b. Skin and mucous membranes c. Musculoskeletal strength d. Level of orientation

ANS: A Early cardiovascular changes for a client experiencing moderate acidosis include increased heart rate and cardiac output. As the acidosis worsens, the heart rate decreases and electrocardiographic changes will be present. Central nervous system and neuromuscular system changes do not occur with mild acidosis and should be monitored if the acidosis worsens. Skin and mucous membrane assessment is not a priority now, but will change as acidosis worsens.

The nurse reads in the medical record that a client has Kussmaul respirations. Which assessment finding is consistent with this condition? a. Deep, rapid respirations b. Respirations with an irregular pattern c. Shallow, grunting respirations d. Use of accessory muscles when breathing

ANS: A Kussmaul respirations are described as deep and rapid and are the body's attempt to compensate for acidosis by "blowing off" excess H+ in the form of carbon dioxide.

A nurse assesses a client who is admitted with an acid-base imbalance. The client's arterial blood gas values are pH 7.32, PaO2 85 mm Hg, PaCO2 34 mm Hg, and HCO3- 16 mEq/L. What action should the nurse take next? a. Assess client's rate, rhythm, and depth of respiration. b. Measure the client's pulse and blood pressure. c. Document the findings and continue to monitor. d. Notify the physician as soon as possible.

ANS: A Progressive skeletal muscle weakness is associated with increasing severity of acidosis. Muscle weakness can lead to severe respiratory insufficiency. Acidosis does lead to dysrhythmias (due to hyperkalemia), but these would best be assessed with cardiac monitoring. Findings should be documented, but simply continuing to monitor is not sufficient. Before notifying the physician, the nurse must have more data to report.

The nurse monitors the client with which condition most carefully for metabolic alkalosis? a. A critical illness receiving total parenteral nutrition b. Type 1 diabetes on once-daily insulin therapy c. Metastatic breast cancer on continuous IV morphine d. Asthma using an adrenergic agonist inhaler

ANS: A The IV fluid mixture for total parenteral nutrition (TPN) has an overall basic pH. One common substance in TPN is lactate, which is rapidly converted in the body to bicarbonate. In addition, the TPN mixture is often administered as a continuous slow infusion. A client with diabetes would be at higher risk of metabolic acidosis. The client on IV morphine is more at risk for respiratory acidosis, as is the client with asthma.

A client has just experienced a 90-second tonic-clonic seizure and has these arterial blood gas values: pH 6.88, HCO3- 22 mEq/L, PCO2 60 mm Hg, PO2 50 mm Hg. Which intervention by the nurse is most appropriate? a. Apply oxygen by mask or nasal cannula. b. Apply a paper bag over the client's nose and mouth. c. Administer 50 mL of sodium bicarbonate intravenously. d. Administer 50 mL of 20% glucose and 20 units of regular insulin.

ANS: A The client has experienced a combination of metabolic and acute respiratory acidosis through heavy skeletal muscle contractions and no gas exchange. When the seizures have stopped and the client can breathe again, the fastest way to return to acid-base balance is to administer oxygen. Sodium bicarbonate should not be administered because the client's arterial bicarbonate level is normal. Applying a paper bag over the client's nose and mouth would worsen the acidosis.

A nurse is caring for a client who has chronic emphysema and is receiving oxygen therapy at 6 L/min via nasal cannula. The following clinical data are available: Arterial Blood Gases Vital Signs pH = 7.28 Pulse rate = 96 beats/min PaO2 = 85 mm Hg Blood pressure = 135/45 PaCO2 = 55 mm Hg Respiratory rate = 6 breaths/min HCO3- = 26 mEq/L O2 saturation = 88% Which action should the nurse take first? a. Notify the Rapid Response Team and provide ventilation support. b. Change the nasal cannula to a mask and reassess in 10 minutes. c. Place the client in Fowler's position if he or she is able to tolerate it. d. Decrease the flow rate of oxygen to 2 to 4 L/min, and reassess.

ANS: A The primary trigger for respiration in a client with chronic respiratory acidosis is a decreased arterial oxygen level (hypoxic drive). Oxygen therapy can inhibit respiratory efforts in this case, eventually causing respiratory arrest and death. The nurse could decrease the oxygen flow rate; eventually, this might improve the client's respiratory rate, but the priority action would be to call the Rapid Response Team whenever a client with chronic carbon dioxide retention has a respiratory rate less than 10 breaths/min. Changing the cannula to a mask does nothing to improve the client's hypoxic drive, nor would it address the client's most pressing need. Positioning will not help the client breathe at a normal rate or maintain client safety.

A nurse assesses a client with diabetes mellitus who is admitted with an acid-base imbalance. The client's arterial blood gas values are pH 7.36, PaO2 98 mm Hg, PaCO2 33 mm Hg, and HCO3- 18 mEq/L. Which manifestation should the nurse identify as an example of the client's compensation mechanism? a. Increased rate and depth of respirations b. Increased urinary output c. Increased thirst and hunger d. Increased release of acids from the kidneys

ANS: A This client has metabolic acidosis. The respiratory system compensates by increasing its activity and blowing off excess carbon dioxide. Increased urinary output, thirst, and hunger are manifestations of hyperglycemia but are not compensatory mechanisms for acid-base imbalances. The kidneys do not release acids.

A nurse assesses a client who is experiencing an acid-base imbalance. The client's arterial blood gas values are pH 7.32, PaO2 94 mm Hg, PaCO2 34 mm Hg, and HCO3- 18 mEq/L. For which clinical manifestations should the nurse assess? (Select all that apply.) a. Reduced deep tendon reflexes b. Drowsiness c. Increased respiratory rate d. Decreased urinary output e. Positive Trousseau's sign

ANS: A, B, C Metabolic acidosis causes neuromuscular changes, including reduced muscle tone and deep tendon reflexes. Clients usually present with lethargy and drowsiness. The respiratory system will attempt to compensate for the metabolic acidosis; therefore, respirations will increase rate and depth. A positive Trousseau's sign is associated with alkalosis. Decreased urine output is not a manifestation of metabolic acidosis.

A nurse is planning interventions that regulate acid-base balance to ensure the pH of a client's blood remains within the normal range. Which abnormal physiologic functions may occur if the client experiences an acid-base imbalance? (Select all that apply.) a. Reduction in the function of hormones b. Fluid and electrolyte imbalances c. Increase in the function of selected enzymes d. Excitable cardiac muscle membranes e. Increase in the effectiveness of many drugs

ANS: A, B, D Acid-base imbalances interfere with normal physiology, including reducing the function of hormones and enzymes, causing fluid and electrolyte imbalances, making heart membranes more excitable, and decreasing the effectiveness of many drugs.

In the client with alkalosis, the nurse assesses for which clinical manifestations? (Select all that apply.) a. Positive Chvostek's sign b. Positive Trousseau's sign c. Hyporeflexia d. Bradycardia e. Elevated blood pressure f. Elevated urinary output

ANS: A, B, D The client with alkalosis demonstrates signs of hypocalcemia and decreased heart rate. Many symptoms are the result of low calcium levels (hypocalcemia) and low potassium levels (hypokalemia), which usually occur with alkalosis. These problems change the function of the nervous, neuromuscular, cardiac, and respiratory systems.

Which assessment findings indicate to the nurse that a child has excess fluid volume? Select all that apply. a. Weight gain b. Decreased blood pressure c. Moist breath sounds d. Poor skin turgor e. Rapid bounding pulse

ANS: A, C, E A child with fluid volume excess will have a weight gain, moist breath sounds due to the excess fluid in the pulmonary system, and a rapid bounding pulse. Other signs seen with fluid volume excess are increased blood pressure, edema, and fatigue. Decreased blood pressure and poor skin turgor are signs of fluid volume deficit.

A nurse assesses a client who is receiving total parenteral nutrition. For which adverse effects related to an acid-base imbalance should the nurse assess? (Select all that apply.) a. Positive Chvostek's sign b. Elevated blood pressure c. Bradycardia d. Increased muscle strength e. Anxiety and irritability

ANS: A, E A client receiving total parenteral nutrition is at risk for metabolic alkalosis. Manifestations of metabolic alkalosis include positive Chvostek's sign, normal or low blood pressure, increased heart rate, skeletal muscle weakness, and anxiety and irritability.

Which client would be appropriate to assign to the new nurse working on the medical-surgical unit? a. Client with diabetic ketoacidosis and change in mental status who has a pH of 7.18 b. Client with emphysema and cellulitis with a PaCO2 level of 58 mm Hg c. Client with reactive airway disease, wheezing, and a PaO2 level of 62 mm Hg d. Client with a small bowel obstruction and vomiting with a bicarbonate level of 40 mEq/L

ANS: B A PaCO2 level of 58 mm Hg in the client with emphysema and cellulitis, although abnormal, is anticipated for a client with chronic obstructive pulmonary disease and is stable for assignment to a new graduate. The client with diabetic ketoacidosis and change in mental status is unstable and requires care by a more experienced nurse. The client with reactive airway disease is still wheezing, and requires experienced nursing care. The client with a small bowel obstruction is unstable and may likely require surgery, which requires more experienced nursing care.

A client has moderate metabolic alkalosis. What is the priority intervention for the nurse? a. Monitor daily laboratory values. b. Assess the client's muscle strength. c. Determine the cause of the problem. d. Teach the client preventive measures.

ANS: B Although all options are viable nursing interventions, the priority is providing for client safety. Clients with metabolic alkalosis have muscle weakness and thus are at risk for falling.

What is the best response by the nurse to a parent asking about antidiarrheal medication for her 18-month-old child? a. "It is okay to give antidiarrheal medication to a young child as long as you follow the directions on the box for correct dosage." b. "Antidiarrheal medication is not recommended for young children because it slows the body's attempt to rid itself of the pathogen." c. "I'm sure your child won't like the taste, so give extra fluids when you give the medication." d. "Antidiarrheal medication will lessen the frequency of stools, but give your child Gatorade to maintain electrolyte balance."

ANS: B Antidiarrheal medications are not recommended for children younger than 2 years old. Antidiarrheal medications may actually prolong diarrhea because the body will retain the organism causing the diarrhea, further increasing fluid and electrolyte losses. The use of these medications is not recommended for children younger than 2 years old because of their binding nature and potential for toxicity. This action is inappropriate because antidiarrheal medications should not be given to a child younger than 2 years old. It is not appropriate to advise a parent to use antidiarrheal medication for a child younger than 2 years old. Education about appropriate oral replacement fluids includes avoidance of sugary drinks, apple juice, sports beverages, and colas.

The nurse is caring for a client who has taken a large quantity of furosemide (Lasix) to promote weight loss. The nurse anticipates the finding of which acid-base imbalance? a. PaO2 of 78 mm Hg b. HCO3- of 34 mEq/L c. PaCO2 of 56 mm Hg d. pH of 7.31

ANS: B Diuretics (non-potassium-sparing), evidenced by a finding of HCO3- of 34 mEq/L, cause metabolic alkalosis. A PaO2 of 78 mm Hg demonstrates mild hypoxemia consistent with respiratory disorders, not with diuretic use. CO2 retention results from hypoventilation, which is not consistent with diuretic use. A pH of 7.31 is acidotic; diuretics promote metabolic alkalosis.

Which client is most likely to exhibit the following ABG results: pH, 7.30; PaCO2, 49; HCO3-, 26; PaO2, 76? a. Client with kidney failure b. Client taking hydromorphone (Dilaudid) c. Client with anxiety disorder d. Client with hyperkalemia

ANS: B Hydromorphone (Dilaudid), a narcotic analgesic, can cause respiratory depression, hypoventilation, and respiratory acidosis, as this blood gas reading demonstrates. Kidney failure causes metabolic acidosis. Anxiety will cause hyperventilation and subsequent respiratory alkalosis. Although hyperkalemia can be caused by acidosis, it is not a cause of acidosis.

A preschooler with severe vomiting and diarrhea was admitted to the hospital. The vomiting has stopped and rehydration has begun intravenously. When should the nurse begin feeding the child solid food? A. When the parents give their permission to feed their child B. After the child has been rehydrated C. After the diarrhea has stopped for 24 hours D. When the IV rehydration can be stopped

ANS: B It is not up to the parents to decide when resumption of solid food begins. Feeding of solids or formula is started as soon as the child is rehydrated. Children should be encouraged to eat frequently—every 3 to 4 hours. Parents should be instructed that although stool output may increase, feeding will not prolong diarrhea, and the child will be absorbing necessary nutrients and calories. Parents should be instructed that although stool output may increase, feeding will not prolong diarrhea, and the child will be absorbing necessary nutrients and calories. The intravenous solutions may run a little longer to ensure that the child remains hydrated.

A toddler is hospitalized with severe dehydration. The nurse should assess the child for which possible complication? A. Hypertension B. Hypokalemia C. A rapid, bounding pulse D. Decreased specific gravity

ANS: B The child needs to be monitored for hypotension. Hypokalemia is a concern in severe dehydration. A rapid, thready pulse would be seen in severe dehydration. The urine would be concentrated, so the specific gravity would increase.

What is the most important factor in determining the rate of fluid replacement in the dehydrated child? a. The child's weight b. The type of dehydration c. Urine output d. Serum potassium level

ANS: B The child's weight determines the amount of fluid needed, not the rate of fluid replacement. One milliliter of body fluid is equal to 1 g of body weight; therefore a loss of 1 kg (2.2 lb) is equal to 1 L of fluid. Isonamtremic and hyponatremic dehydration resuscitation involves fluid replacement over 24 hours. Hypernatremic dehydration involves a slower replacement rate to prevent a sudden decrease in the sodium level. Urine output is not a consideration for determining the rate of administration of replacement fluids. Potassium level is not as significant in determining the rate of fluid replacement as the type of dehydration.

A nurse is caring for a client who has the following arterial blood values: pH 7.12, PaO2 56 mm Hg, PaCO2 65 mm Hg, and HCO3- 22 mEq/L. Which clinical situation should the nurse correlate with these values? a. Diabetic ketoacidosis in a person with emphysema b. Bronchial obstruction related to aspiration of a hot dog c. Anxiety-induced hyperventilation in an adolescent d. Diarrhea for 36 hours in an older, frail woman

ANS: B Arterial blood gas values indicate that the client has acidosis with normal levels of bicarbonate, suggesting that the problem is not metabolic. Arterial concentrations of oxygen and carbon dioxide are abnormal, with low oxygen and high carbon dioxide levels. Thus, this client has respiratory acidosis from inadequate gas exchange. The fact that the bicarbonate level is normal indicates that this is an acute respiratory problem rather than a chronic problem, because no renal compensation has occurred.

A client has acidosis. Which laboratory finding is of greatest concern to the nurse? a. Sodium 154 mEq/L b. Potassium 5.9 mEq/L c. Calcium 8.9 mg/dL d. Magnesium 2.1 mg/dL

ANS: B In the client with acidosis, intracellular buffering leads to entry of hydrogen ions (H+) into cells, and in return potassium leaves the cell. This leads to elevated serum potassium levels. Many severe problems with acidosis are due to the accompanying hyperkalemia.

Which client does the nurse assess for potential metabolic acidosis? a. Client admitted after collapsing during a marathon run b. Young adult following a carbohydrate-free diet c. Older adult with asthma who is on long-term steroid therapy d. Older client on antacids for gastroesophageal reflux disease

ANS: B One cause of acidosis is a strict low-calorie diet or one that is low in carbohydrate content. Such a diet increases the rate of fat catabolism and results in the formation of excessive ketoacids. Dehydration is not directly associated with acid-base disorders. In the client with asthma, acid-base status will be determined by a combination of depth of respirations and oxygen saturation. Excessive intake of sodium bicarbonate may increase the risk of metabolic alkalosis

A client is being discharged from the emergency department with several broken ribs. For which acid-base imbalance does the nurse provide discharge teaching? a. Respiratory alkalosis from anxiety and hyperventilation b. Respiratory acidosis from inadequate ventilation c. Metabolic acidosis from calcium loss from broken bones d. Metabolic alkalosis from taking base-containing analgesics

ANS: B Pain from broken ribs often causes the client to breathe more shallowly to avoid moving his or her ribs and increasing pain. If respiration is shallow enough, ventilation is inadequate, leading to poor gas exchange and respiratory acidosis. Hyperventilation would more likely cause respiratory alkalosis. The calcium loss from broken ribs probably would not affect acid-base balance. Taking analgesics as prescribed for pain probably also would not affect acid-base balance.

A client is in the emergency department after an overdose of an unknown substance. Which assessment findings does the nurse correlate with possible salicylate poisoning? a. Increased deep tendon reflexes b. Increased rate and depth of respiration c. Decreased capillary refill d. Decreased intestinal motility and paralytic ileus

ANS: B Salicylates are acidic, and salicylate poisoning increases the rate and depth of ventilation in two ways. First, salicylates directly stimulate the respiratory centers. Second, by causing a metabolic acidosis and reducing the pH of the blood, the respiratory centers are stimulated to compensate.

A client who was malnourished is being discharged. The nurse evaluates that teaching to decrease risk for the development of metabolic acidosis has been effective when the client states, "I will: a. Increase my milk intake to at least three glasses daily." b. Be sure to eat three well-balanced meals and a snack daily." c. Avoid taking pain medication and antihistamines together." d. Not add salt to food when cooking or during meals."

ANS: B Starvation or a diet with too few carbohydrates can lead to metabolic acidosis by forcing cells to switch to using fats for fuel and by creating ketoacids as a by-product of excessive fat metabolism. Eating sufficient calories from all food groups helps reduce this risk.

A nurse evaluates the following arterial blood gas values in a client: pH 7.48, PaO2 98 mm Hg, PaCO2 28 mm Hg, and HCO3- 22 mEq/L. Which client condition should the nurse correlate with these results? a. Diarrhea and vomiting for 36 hours b. Anxiety-induced hyperventilation c. Chronic obstructive pulmonary disease (COPD) d. Diabetic ketoacidosis and emphysema

ANS: B The elevated pH level indicates alkalosis. The bicarbonate level is normal, and so is the oxygen partial pressure. Loss of carbon dioxide is the cause of the alkalosis, which would occur in response to hyperventilation. Diarrhea and vomiting would cause metabolic alterations, COPD would lead to respiratory acidosis, and the client with emphysema most likely would have combined metabolic acidosis on top of a mild, chronic respiratory acidosis.

A nurse is planning care for a client who is hyperventilating. The client's arterial blood gas values are pH 7.30, PaO2 94 mm Hg, PaCO2 31 mm Hg, and HCO3- 26 mEq/L. Which question should the nurse ask when developing this client's plan of care? a. "Do you take any over-the-counter medications?" b. "You appear anxious. What is causing your distress?" c. "Do you have a history of anxiety attacks?" d. "You are breathing fast. Is this causing you to feel light-headed?

ANS: B The nurse should assist the client who is experiencing anxiety-induced respiratory alkalosis to identify causes of the anxiety. The other questions will not identify the cause of the acid-base imbalance.

The nurse prepares to administer bicarbonate intravenously to the client with which clinical manifestations? a. pH 7.28, HCO3- 22 mEq/L, PCO2 52 mm Hg, PO2 82 mm Hg secondary to an acute asthma attack b. pH 7.28, HCO3- 16 mEq/L, PCO2 45 mm Hg, PO2 98 mm Hg secondary to excessive diarrhea c. Client with chronic emphysema and bronchitis who has the following arterial blood gases: pH 7.30, HCO3- 30 mEq/L, PCO2 60 mm Hg, PO2 72 mm Hg secondary to chronic bronchitis and emphysema d. pH 7.31, HCO3- 20 mEq/L, PCO2 34 mm Hg, PO2 96 mm Hg secondary to a urinary tract infection and type 2 diabetes

ANS: B The only client who has lower than normal bicarbonate levels is the client with diarrhea. This deficit is most likely the result of an actual bicarbonate loss, and bicarbonate should be replaced to help return this client's acid-base balance to normal. Giving bicarbonate to any of the other clients listed would be adding too much base and would risk the development of alkalosis.

A nurse is assessing a client who has acute pancreatitis and is at risk for an acid-base imbalance. For which manifestation of this acid-base imbalance should the nurse assess? a. Agitation b. Kussmaul respirations c. Seizures d. Positive Chvostek's sign

ANS: B The pancreas is a major site of bicarbonate production. Pancreatitis can cause a relative metabolic acidosis through underproduction of bicarbonate ions. Manifestations of acidosis include lethargy and Kussmaul respirations. Agitation, seizures, and a positive Chvostek's sign are manifestations of the electrolyte imbalances that accompany alkalosis.

A nurse is caring for a client who is experiencing excessive diarrhea. The client's arterial blood gas values are pH 7.28, PaO2 98 mm Hg, PaCO2 45 mm Hg, and HCO3- 16 mEq/L. Which provider order should the nurse expect to receive? a. Furosemide (Lasix) 40 mg intravenous push b. Sodium bicarbonate 100 mEq diluted in 1 L of D5W c. Mechanical ventilation d. Indwelling urinary catheter

ANS: B This client's arterial blood gas values represent metabolic acidosis related to a loss of bicarbonate ions from diarrhea. The bicarbonate should be replaced to help restore this client's acid-base balance. Furosemide would cause an increase in acid fluid and acid elimination via the urinary tract; although this may improve the client's pH, the client has excessive diarrhea and cannot afford to lose more fluid. Mechanical ventilation is used to treat respiratory acidosis for clients who cannot keep their oxygen saturation at 90%, or who have respirator muscle fatigue. Mechanical ventilation and an indwelling urinary catheter would not be prescribed for this client.

Why are infants at greater risk for fluid and electrolyte imbalances than older children? A. Their metabolic rate is lower. B. They have a decreased surface area. C. Their kidney functioning is immature. D. Their daily exchange of extracellular fluid is decreased.

ANS: C The infant has a higher metabolic rate. The infant has a proportionately greater body surface area, which allows for greater insensible water loss. The infant's kidneys are unable to concentrate or dilute urine, conserve or excrete sodium, and acidify urine. There is an increased amount of extracellular fluid in the infant. Forty percent of a neonate's body fluid is extracellular fluid, compared with 20% in an adult. Fluid is lost from the extracellular space first.

A nurse is planning care for a client who is anxious and irritable. The client's arterial blood gas values are pH 7.30, PaO2 96 mm Hg, PaCO2 43 mm Hg, and HCO3- 19 mEq/L. Which questions should the nurse ask the client and spouse when developing the plan of care? (Select all that apply.) a. "Are you taking any antacid medications?" b. "Is your spouse's current behavior typical?" c. "Do you drink any alcoholic beverages?" d. "Have you been experiencing any vomiting?" e. "Are you experiencing any shortness of breath?"

ANS: B, C This client's symptoms of anxiety and irritability are related to a state of metabolic acidosis. The nurse should ask the client's spouse or family members if the client's behavior is typical for him or her, and establish a baseline for comparison with later assessment findings. The nurse should also assess for alcohol intake because alcohol can change a client's personality and cause metabolic acidosis. The other options are not causes of metabolic acidosis.

A nurse is assessing clients who are at risk for acid-base imbalance. Which clients are correctly paired with the acid-base imbalance? (Select all that apply.) a. Metabolic alkalosis - Young adult who is prescribed intravenous morphine sulfate for pain b. Metabolic acidosis - Older adult who is following a carbohydrate-free diet c. Respiratory alkalosis - Client on mechanical ventilation at a rate of 28 breaths/min d. Respiratory acidosis - Postoperative client who received 6 units of packed red blood cells e. Metabolic alkalosis - Older client prescribed antacids for gastroesophageal reflux disease

ANS: B, C, E Respiratory acidosis often occurs as the result of underventilation. The client who is taking opioids, especially IV opioids, is at risk for respiratory depression and respiratory acidosis. One cause of metabolic acidosis is a strict low-calorie diet or one that is low in carbohydrate content. Such a diet increases the rate of fat catabolism and results in the formation of excessive ketoacids. A ventilator set at a high respiratory rate or tidal volume will cause the client to lose too much carbon dioxide, leading to an acid deficit and respiratory alkalosis. Citrate is a substance used as a preservative in blood products. It is not only a base, it is also a precursor for bicarbonate. Multiple units of packed red blood cells could cause metabolic alkalosis. Sodium bicarbonate antacids may increase the risk of metabolic alkalosis.

A school-age child with acute diarrhea and mild dehydration is being given oral rehydration solutions (ORS). The child's mother calls the clinic nurse to report the child has occasional vomiting. What is the appropriate recommendation by the nurse? A. Bring the child to the hospital for intravenous fluids. B. Alternate giving the child ORS and carbonated drinks. C. Continue to give the child ORS frequently in small amounts. D. Maintain the child on NPO for 8 hours and resume ORS if vomiting subsides.

ANS: C A school-age child with mild dehydration can be rehydrated safely at home with oral solutions. Carbonated drinks should not be given to the child. They may have a high carbohydrate content and contain caffeine, which is a diuretic. Vomiting is not a contraindication to the use of ORS unless it is severe. The mother should continue to give the ORS in small amounts and at frequent intervals. NPO status is not indicated. Frequent intake of ORS in small amounts is recommended.

In the client with hypoventilation, which change in arterial blood gases does the nurse evaluate to determine whether treatment measures are being effective? a. Decreased arterial blood pH b. Decreased arterial blood carbon dioxide c. Increased arterial blood bicarbonate d. Increased arterial blood oxygen

ANS: C Because kidneys regulate pH by controlling bicarbonate concentration and the lungs regulate pH by controlling carbon dioxide loss, loss of one function can be at least partially compensated for by the other function. When pulmonary function is decreased, so that adequate amounts of carbon dioxide are not excreted, the pH falls, stimulating the kidneys to reabsorb more bicarbonate to balance the increased acid production.

Which assessment is most relevant to the care of an infant with dehydration? a. Temperature, heart rate, and blood pressure. b. Respiratory rate, oxygen saturation, and lung sounds. c. Heart rate, sensorium, and skin color. d. Diet tolerance, bowel function, and abdominal girth.

ANS: C Children can compensate and maintain an adequate cardiac output when they are hypovolemic. Blood pressure is not as reliable an indicator of shock as are changes in heart rate, sensorium, and skin color. Respiratory assessments will not provide data about impending hypovolemic shock. Changes in heart rate, sensorium, and skin color are early indicators of impending shock in the child. Diet tolerance, bowel function, and abdominal girth are not as important indicators of shock as heart rate, sensorium, and skin color.

What assessment should the nurse make before initiating an intravenous (IV) infusion of dextrose 5% in 0.9% normal saline solution with 10 mEq of potassium chloride for a child hospitalized with dehydration? a. Fluid intake b. Number of stools c. Urine output d. Capillary refill

ANS: C Fluid intake does not give information about renal function. Stool count sheds light on intestinal function. Renal function is the concern before potassium chloride is added to an IV solution. Potassium chloride should never be added to an IV solution in the presence of oliguria or anuria (urine output less than 0.5 mL/kg/hr). Assessment of capillary refill does not provide data about renal function.

In a client 4 minutes post cardiac arrest, the nurse correlates the largest source of excess hydrogen ions with which cause? a. Excess renal retention of carbon dioxide due to hypoxia b. Release of intracellular acids due to widespread tissue destruction c. Anaerobic metabolism, leading to the buildup of lactic acid d. Using fat as a fuel source, resulting in increased fat degradation

ANS: C Glucose metabolism continues under anaerobic conditions to supply the body with chemical energy (adenosine triphosphate [ATP]). However, this metabolism is incomplete, stopping at lactic acid production instead of continuing into the Krebs' cycle. This results in a large buildup of lactic acid, which releases excessive amounts of hydrogen ions into the blood.

The nurse is caring for a group of clients with acidosis. The nurse recognizes that Kussmaul respirations are consistent with which situation? a. Client receiving mechanical ventilation b. Use of hydrochlorothiazide c. Aspirin overdose d. Administration of sodium bicarbonate

ANS: C If acidosis is metabolic in origin, the rate and depth of breathing increase as the hydrogen ion level rises; this is known as Kussmaul respirations. Metabolic acidosis is caused by alcoholic beverages, methyl alcohol, and acetylsalicylic acid (aspirin). Mechanical ventilation is used to correct hypoxemia and hypercapnia (elevated PaCO2). Hydrochlorothiazide causes metabolic alkalosis. Sodium bicarbonate is used in the treatment of metabolic acidosis; administration of this buffer may cause metabolic alkalosis.

Which acid-base imbalance does the nurse anticipate the client with morbid obesity may develop? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis

ANS: C Respiratory acidosis is related to CO2 retention secondary to respiratory depression, inadequate chest expansion, airway obstruction, and reduced alveolar-capillary diffusion, which are common in morbidly obese clients who experience inadequate chest expansion owing to their size and work of breathing. Metabolic acidosis is related to overproduction of hydrogen ions, underelimination of hydrogen ions, underproduction of bicarbonate ions, and overelimination of bicarbonate ions. Metabolic alkalosis is related to loss of bicarbonate or buffers (i.e., vomiting or nasogastric suction). Respiratory alkalosis usually is caused by excessive loss of CO2 through hyperventilation secondary to fever, central nervous system lesions, and salicylates.

The nurse is caring for a client with an oxygen saturation of 88% and accessory muscle use. The nurse provides oxygen and anticipates which of these health care provider orders? a. Administration of IV sodium bicarbonate b. Computed tomography of the chest, STAT c. Intubation and mechanical ventilation d. Administration of concentrated potassium chloride solution

ANS: C Support with mechanical ventilation may be needed for clients who cannot keep their oxygen saturation at 90% or who have respiratory muscle fatigue. Sodium bicarbonate is used to treat metabolic acidosis; this client displays hypoxemia. Although the underlying reason for this client's hypoxemia may eventually require a diagnostic study, the priority is to restore oxygenation. No indication suggests that this client has hypokalemia; signs of hypoxemia and work of breathing are present, requiring correction with intubation and mechanical ventilation.

The nurse assesses for acidosis in the client with which assessment data? a. Serum sodium level of 130 mEq per liter and peripheral edema b. Serum sodium level of 144 mEq per liter and tachycardia c. Serum potassium level of 6.5 mEq per liter and flaccid paralysis d. Serum potassium level of 4.5 mEq per liter and hyperactive deep tendon reflexes

ANS: C When acidosis is present, the hydrogen ion concentration of the extracellular fluid (ECF) is increased above normal. The physiologic action to reduce the ECF hydrogen ion concentration is to move the hydrogen ions into the cells in exchange for potassium ions, thereby maintaining the electroneutrality of the intracellular fluid. As a result, acidosis is accompanied by hyperkalemia, which diminishes nerve and skeletal muscle excitability, causing flaccid paralysis.

A client has respiratory acidosis. The nurse evaluates that treatment is being effective with which arterial blood gas values? a. pH 7.28, HCO3- 12 mEq/L, PCO2 45 mm Hg, PO2 96 mm Hg b. pH 7.32, HCO3- 17 mEq/L, PCO2 25 mm Hg, PO2 98 mm Hg c. pH 7.35, HCO3- 36 mEq/L, PCO2 65 mm Hg, PO2 78 mm Hg d. pH 7.48, HCO3- 12 mEq/L, PCO2 35 mm Hg, PO2 85 mm Hg

ANS: C A pH of 7.35 is normal, indicating acid-base balance (fully compensated). A respiratory problem with carbon dioxide retention and inadequate gas exchange is apparent from the high PCO2 and the low PO2. The bicarbonate level is greatly elevated, indicating renal synthesis and reabsorption of HCO3-, a powerful acid-base compensatory mechanism. Thus, the amount of bicarbonate (base) in the blood adequately compensates for the increased carbon dioxide level, so that the pH is normal, although no other arterial blood gas value is normal.

In clients with any type of acid-base imbalance, the nurse places the priority on monitoring which electrolyte? a. Sodium b. Calcium c. Potassium d. Magnesium

ANS: C Any type of acid-base imbalance usually alters the blood potassium level. Both potassium and hydrogen ions carry or express an overall positive charge (cations). Body fluids maintain electroneutrality by keeping the number of positive ions matched with an equal number of negative ions (anions). In acidosis, hydrogen ions enter cells in exchange for potassium ions. Thus, a relative hyperkalemia accompanies acidosis. In alkalosis, hydrogen ions leave the cells and enter the blood in exchange for potassium ions. Thus, a relative hypokalemia usually accompanies alkalosis as extracellular potassium ions move into cells in exchange for intracellular hydrogen ions entering the extracellular fluid. The normal potassium level of the blood has a narrow range (3.5 to 5.0 mEq/L). When blood potassium levels are too high, lethal cardiac dysrhythmias may occur. When blood potassium levels are too low, skeletal muscle weakness and respiratory failure may occur.

A client has metabolic alkalosis. Which laboratory results is the nurse most likely to assess as consistent with this condition? a. Na+ 134 mg/dL b. Mg2+ 1.5 mg/dL c. K+ 3.1 mEq/L d. Ca2+ 11.5 mg/dL

ANS: C Both potassium and hydrogen ions carry or express an overall positive charge (cations). Body fluids maintain electroneutrality by keeping the number of positive ions matched with an equal number of negative ions (anions). A compensation of alkalosis is the movement of hydrogen ions into cells inside the blood and other extracellular fluids. To prevent the blood from expressing too many positive charges, another positive ion must leave the blood and enter the cells. Potassium is the positive ion that usually is exchanged for a hydrogen ion. Thus, a relative hypokalemia usually accompanies alkalosis as extracellular potassium ions move into cells in exchange for intracellular hydrogen ions entering the extracellular fluid.

The nurse monitors for which acid-base imbalance in a client who has hypoxemia? a. Reduced carbon dioxide production leading to alkalosis b. Reduced carbon dioxide retention leading to alkalosis c. Excess carbon dioxide production leading to acidosis d. Excess carbon dioxide retention leading to acidosis

ANS: C Hypoxemia (lower than normal blood oxygen level) causes some organs, tissues, and cells to have anaerobic metabolism. This situation leads to a buildup of carbon dioxide. Elevated levels of carbon dioxide lead to an increase in blood hydrogen ion levels and acidosis.

A client has a prolonged fever. For which acid-base imbalance does the nurse assess the client further? a. Metabolic acidosis from excess bicarbonate production b. Metabolic alkalosis from dehydration and hyperkalemia c. Metabolic acidosis from increased production of hydrogen ions d. Respiratory alkalosis from impaired gas exchange

ANS: C Increased body temperature is associated with hypermetabolism and increases the rate at which hydrogen ions are produced. Increased bicarbonate production would lead to metabolic alkalosis. Hyperkalemia leads to metabolic acidosis. Having a fever would not directly lead to gas exchange problems.

A client has the following arterial blood gases: pH 7.30, HCO3- 17 mEq/L, PCO2 25 mm Hg, PO2 98 mm Hg. Which intervention by the nurse is most appropriate? a. Prepare to give intravenous sodium bicarbonate. b. Document the findings and continue to assess. c. Assist the physician in determining the cause. d. Administer oxygen at 2 L per nasal cannula.

ANS: C The client has a partially compensated metabolic acidosis. Interventions are aimed at reducing or eliminating the cause. The nurse needs to assist in determining the cause so that proper interventions can be initiated. Sodium bicarbonate is rarely used for acidosis unless the pH is life threatening, or for specific causes of acidosis wherein bicarbonate deficit is known to be the problem. Simply documenting the findings will not help the client. Because the client's PO2 is 98 mm Hg, oxygen therapy is not indicated on the basis of these arterial blood gases.

A client is admitted with mixed respiratory and metabolic acidosis secondary to bronchitis and diabetic ketoacidosis. The nurse evaluates that teaching about the client's confusion was effective when a family member makes which statement? a. "It is too early to tell if the ketoacidosis will cause permanent changes." b. "Her memory will improve, but loss of some brain cells has occurred." c. "The confusion should clear when oxygen and electrolyte levels are normal." d. "The confusion should clear when blood glucose levels and other laboratory tests are normal."

ANS: C The pH abnormality alone is not responsible for the confusion. Most of the confusion is caused by hypoxia in combination with electrolyte imbalances that accompany severe combined acidosis. None of the other options address the client's hypoxia.

The nurse interprets which arterial blood gas values as partially compensated metabolic acidosis? a. pH 7.28, HCO3- 19 mEq/L, PCO2 45 mm Hg, PO2 96 mm Hg b. pH 7.45, HCO3- 22 mEq/L, PCO2 40 mm Hg, PO2 98 mm Hg c. pH 7.32, HCO3- 17 mEq/L, PCO2 25 mm Hg, PO2 98 mm Hg d. pH 7.48, HCO3- 28 mEq/L, PCO2 45 mm Hg, PO2 92 mm Hg

ANS: C The pH is lower than normal, indicating mild acidosis. The acidosis is metabolic in origin, as indicated by the normal arterial oxygen partial pressure and the low bicarbonate level. The decreased carbon dioxide level indicates an increased respiratory rate, causing the carbon dioxide to be blown off and bringing the pH closer to normal (but not completely normal). Thus, the metabolic acidosis is only partially compensated for by the respiratory effort.

A client has an arterial blood gas pH of 7.48. How does the nurse interpret this client's acid-base status? a. An unknown acid-base balance status b. A normal blood hydrogen ion concentration c. A deficit in blood hydrogen ion concentration d. An excess in blood hydrogen ion concentration

ANS: C The pH is the negative log of the hydrogen ion concentration. The normal pH of arterial blood ranges between 7.35 and 7.45. A pH of 7.48 indicates a decrease in the hydrogen ion concentration (alkalosis).

Which statement best describes why infants are at greater risk for dehydration than older children? a. Infants have an increased ability to concentrate urine. b. Infants have a greater volume of intracellular fluid. c. Infants have a smaller body surface area. d. Infants have an increased extracellular fluid volume.

ANS: D Because the kidneys are immature in early infancy, there is a decreased ability to concentrate the urine. Infants have a larger proportion of fluid in the extracellular space. Infants have proportionately greater body surface area in relation to body mass, which creates the potential for greater fluid loss through the skin and gastrointestinal tract. The larger ratio of extracellular fluid to intracellular fluid predisposes the infant to dehydration.

When a client has an arterial blood pH of 7.48, which buffer action will bring the pH back to normal? a. Absorption of bicarbonate ions from the blood b. Release of bicarbonate ions into the blood c. Absorption of hydrogen ions from the blood d. Release of hydrogen ions into the blood

ANS: D Buffers can act as an acid (releasing a hydrogen ion) or as a base (absorbing a hydrogen ion) to assist in keeping the pH and hydrogen ion concentration of body fluids within the normal range. An arterial pH of 7.48 indicates a deficiency of hydrogen ions. This situation would cause buffers to act like acids and release hydrogen ions into the blood.

A nurse is teaching parents about diarrhea. Which statement by the parents indicates understanding of the teaching? a. Diarrhea results from a fluid deficit in the small intestine. b. Organisms destroy intestinal mucosal cells, resulting in an increased intestinal surface area. c. Malabsorption results in metabolic alkalosis. d. Increased motility results in impaired absorption of fluid and nutrients.

ANS: D Diarrhea results from fluid excess in the small intestine. Destroyed intestinal mucosal cells result in decreased intestinal surface area. Loss of electrolytes in the stool from diarrhea results in metabolic acidosis. Increased motility and rapid emptying of the intestines result in impaired absorption of nutrients and water. Electrolytes are drawn from the extracellular space into stool, and dehydration results.

A nurse is evaluating an infant brought to the clinic with severe diarrhea. What signs and symptoms indicate that the infant has severe dehydration? A. Tachycardia, decreased tears, 5% weight loss B. Normal pulse and blood pressure, intense thirst C. Irritability, moderate thirst, normal eyes and fontanel D. Tachycardia, capillary refill greater than 3 seconds, sunken eyes and fontanel

ANS: D In severe dehydration, there is a 15% weight loss in infants. Tachycardia, orthostatic hypotension and shock, and intense thirst would be expected. The infant would be extremely irritable, with sunken eyes and fontanel. Tachycardia, capillary refill greater than 3 seconds, and sunken eyes and fontanel are the symptoms of severe dehydration.

What is the priority nursing intervention for a 6-month-old infant hospitalized with diarrhea and dehydration? a. Estimating insensible fluid loss b. Collecting urine for culture and sensitivity c. Palpating the posterior fontanel d. Measuring the infant's weight

ANS: D Infants have a greater total body surface area and therefore a greater potential for fluid loss through the skin. It is not possible to measure insensible fluid loss. Urine for culture and sensitivity is not usually part of the treatment plan for the infant who is dehydrated from diarrhea. The posterior fontanel closes by 2 months of age. The anterior fontanel can be palpated during an assessment of an infant with dehydration. Weight is a crucial indicator of fluid status. It is an important criterion for assessing hydration status and response to fluid replacement.

The nurse monitors for which acid-base problem in a client who is taking furosemide (Lasix) for hypertension? a. Acid excess secondary to respiratory acidosis b. Acid deficit secondary to respiratory alkalosis c. Acid excess secondary to metabolic acidosis d. Acid deficit secondary to metabolic alkalosis

ANS: D Many diuretics, especially loop diuretics, increase the excretion of hydrogen ions, leading to excess acid loss through the renal system. This situation is an acid deficit of metabolic origin.

The nurse is caring for a client with hypoxemia and metabolic acidosis. Which task can be delegated to the nursing assistant who is helping with the client's care? a. Assess the client's respiratory pattern. b. Increase the IV normal saline to 120 mL/hr c. Titrate O2 to maintain an O2 saturation of 95% to 100% d. Apply the pulse oximeter for continuous readings

ANS: D Placing a peripheral pulse oximeter is a standardized nursing skill that is within the scope of practice for unlicensed personnel. Assessment and intravenous therapy are skills performed by the professional nurse. Titration of O2 requires assessment and intervention beyond the scope of practice of an unlicensed individual.

The nurse expects to find renal compensation for an acid-base imbalance in which situation? a. Mild to moderate dehydration in a middle-aged client who jogged for 2 hours b. Acute asthma attack with wheezing of 6 hours' duration in an older man c. Food poisoning with vomiting for 12 hours in a middle-aged woman d. Hypoxemia for 4 days from pneumonia in an adult woman

ANS: D Renal compensation (change in excretion or reabsorption of hydrogen ions and bicarbonate ions) for an acid-base imbalance is very potent and requires from many hours up to several days to begin. It does not provide immediate compensation, nor does it respond to acute imbalances. For a person who has been hypoxemic for several days, renal compensation with increased excretion of hydrogen ions and increased reabsorption of bicarbonate would have been initiated.

A child has a 2-day history of vomiting and diarrhea. He has hypoactive bowel sounds and an irregular pulse. Electrolyte values are sodium, 139 mEq/L; potassium, 3.3 mEq/L; and calcium, 9.5 mg/dL. This child is likely to have which of the following electrolyte imbalances? a. Hyponatremia b. Hypocalcemia c. Hyperkalemia d. Hypokalemia

ANS: D The normal serum sodium level is 135 to 145 mEq/L. A level of 139 mEq/L is within normal limits. A serum calcium level less than 8.5 mg/dL is considered hypocalcemia. A serum potassium level greater than 5 mEq/L is considered hyperkalemia. A serum potassium level less than 3.5 mEq/L is considered hypokalemia. Clinical manifestations of hypokalemia include muscle weakness, decreased bowel sounds, cardiac irregularities, hypotension, and fatigue.

Which nursing intervention takes priority for a client admitted with severe metabolic acidosis? a. Perform medication reconciliation b. Assess the client's strength in the extremities c. Obtain a diet history for the past 3 days d. Initiate cardiac monitoring

ANS: D The nurse follows the ABCs and initiates cardiac monitoring to observe for signs of hyperkalemia or cardiac arrest. Medication reconciliation should be performed as soon as possible; however, this client is at risk for cardiac and neurologic complications of acidosis. Starvation may precipitate ketosis/acidosis, but this is not the priority.

A nurse assesses a client who is prescribed furosemide (Lasix) for hypertension. For which acid-base imbalance should the nurse assess to prevent complications of this therapy? a. Respiratory acidosis b. Respiratory alkalosis c. Metabolic acidosis d. Metabolic alkalosis

ANS: D Many diuretics, especially loop diuretics, increase the excretion of hydrogen ions, leading to excess acid loss through the renal system. This situation is an acid deficit of metabolic origin.

A client has severe metabolic alkalosis. Which nursing diagnosis does the nurse choose as the client's priority problem? a. Fluid volume excess related to reduced kidney function b. Fluid volume deficit related to increased insensitive fluid loss through lungs c. Risk for impaired skin integrity related to accompanying peripheral edema d. Risk for injury related to increased neuronal sensitivity from hypocalcemia

ANS: D Metabolic alkalosis is manifested by a high pH, which causes serum calcium to bind and reduces the concentration of free calcium. This relative hypocalcemia increases the risk for increased neuromuscular activity, including tetany and seizures.

The nurse assesses the client with which condition most carefully for the risk of developing acute respiratory acidosis? a. Allergic rhinitis and sinusitis on sulfa antibiotics b. Type 1 diabetes and urinary tract infection c. Emphysema and undergoing nasogastric (NG) tube suctioning d. On patient-controlled analgesia after abdominal surgery

ANS: D Respiratory acidosis often occurs as the result of underventilation. The client who is taking narcotics, especially IV narcotics, is at risk for respiratory depression. The client may also be breathing more shallowly than usual to prevent pain. This gives the client two risk factors for developing hypoventilation and subsequent respiratory acidosis. None of the other clients are at risk for ineffective ventilation.

A client has been NPO after a colectomy with nasogastric (NG) suction in place. On assessment, the nurse finds the client reporting cramps in the calves. Which action by the nurse is most appropriate? a. Document findings and notify the physician. b. Stop suction and request that the laboratory draw arterial blood gases. c. Prepare to administer lorazepam (Ativan). d. Raise the siderails and notify the physician.

ANS: D The client has a metabolic alkalosis probably caused by prolonged suctioning. The client also is experiencing tetany, caused by the accompanying hypocalcemia, and is at risk for seizures. The priority is to maintain the client's safety; this includes raising the siderails and then notifying the physician. Documentation is important but not as important as providing safety. The nurse would not stop the suction without an order. The client may need lorazepam if he or she has seizures, but this is not the first action the nurse would perform.

A nurse is caring for a client who is experiencing moderate metabolic alkalosis. Which action should the nurse take? a. Monitor daily hemoglobin and hematocrit values. b. Administer furosemide (Lasix) intravenously. c. Encourage the client to take deep breaths. d. Teach the client fall prevention measures.

ANS: D The priority nursing care for a client who is experiencing moderate metabolic alkalosis is providing client safety. Clients with metabolic alkalosis have muscle weakness and are at risk for falling. The other nursing interventions are not appropriate for metabolic alkalosis.