Egan's Chapter 14 Test Bank Question with answers rated A+

Egan's Chapter 14 Test Bank Question with answers rated A+ANS: C The primary goal of acid-base homeostasis is to maintain which of the following? a. Normal HCO3- b. Normal PCO2 c. Normal pH d. Normal PO2 ANS: B What is the normal arterial blood pH range? a. 7.25 to 7.35 b. 7.35 to 7.45 c. 7.45 to 7.55 d. 7.55 to 7.65 ANS: B Which of the following is a volatile acid of physiologic significance? a. Hydrochloric b. Carbonic c. Phosphoric d. Lactic ANS: D What are the major mechanisms responsible for maintaining a stable pH despite massive CO2 production? 1. Isohydric buffering 2. Gastrointestinal secretion 3. Pulmonary ventilation a. 2 and 3 only b. 1 and 2 only c. 1, 2, and 3 d. 1 and 3 only ANS: C Fixed acids are produced primarily from the catabolism of which of the following? a. Carbohydrates b. Fats c. Proteins d. Simple sugars ANS: B What is the primary buffer system for fixed acids? a. Cl- b. HCO3- c. Phosphate d. Plasma proteins ANS: B By comparison, how much fixed acid is produced in any given period compared to the volatile acid CO2? a. Approximately the same amount b. Less fixed than volatile c. More fixed than volatile d. CO2 is not a volatile acid ANS: C Which of the following statements about the equilibrium constant of an acid is true? a. The equilibrium constant of a weak acid is large. b. The equilibrium constant of a strong acid is small. c. The equilibrium constant of a weak acid is small. d. The more an acid ionizes, the smaller is the equilibrium constant. ANS: B A solution that resists large changes in pH upon addition of an acid or a base best describes which of the following? a. Acid-base excretor b. Buffer solution c. Catabolic regulator d. Homeostatic control ANS: C When a strong acid is added to the bicarbonate buffer system, what is the result? a. Strong base and neutral salt b. Strong acid and neutral salt c. Weak acid and neutral salt d. Weak acid and basic salt ANS: D Which of the following are components of the body's nonbicarbonate buffer system? 1. Hemoglobin 2. Plasma proteins 3. Organic phosphates 4. Inorganic phosphates a. 1, 2, and 3 only b. 2 and 4 only c. 3 only d. 1, 2, 3, and 4 ANS: A What is the sum of all blood buffers in 1 L of blood? a. Buffer base b. Base excess c. Standard bicarbonate d. Base deficit ANS: C Why is the bicarbonate buffer system considered an open buffer system? a. As the major blood and body buffer system, it is open by definition. b. It operates only in the extracellular fluid, avoiding cell closure. c. Its acid (carbonic acid) is converted to CO2 and removed. d. Its chemical reactions occur very quickly. ANS: A Why is a buffer system such as phosphate considered a closed system? a. All the components remain in the system. b. It has limited utility in buffering acids. c. Its ability to buffer volatile acids is incomplete. d. Once its buffer level is established, it will never change. ANS: D What factor would limit the ability of the H2CO3/HCO3- buffer system to perform efficiently? a. Temperature rise of more than 3° C b. Inadequate amount of 2,3-DPG in the blood c. Increased production of nonvolatile acids d. Lungs failing to excrete adequate levels of CO2 ANS: A Which buffer system has the greatest capacity? a. Bicarbonate b. Hemoglobin c. Phosphates d. Plasma proteins ANS: B What effect does hyperventilation have on the closed buffer systems? a. It causes them to bind with more H+. b. It causes them to release more H+. c. It has no effect on them at all. d. It increases the affinity of the closed buffer system. ANS: D [H+] can be determined by the use of which factors? 1. HCO3- 2. H2CO3 3. Inorganic phosphorus 4. PaO2 a. 1, 2, and 3 only b. 2 and 3 only c. 4 only d. 1 and 2 only ANS: B A patient has a PCO2 of 80 mm Hg. What is the concentration of dissolved CO2 (in mmol/L) in the blood? a. 1.2 mmol/L b. 2.4 mmol/L c. 24 mmol/L d. 40 mmol/L ANS: D Of what use is the Henderson-Hasselbalch equation for a clinician? a. It can guide therapeutic decision for critically ill patients. b. It establishes the baseline values for buffer enhancement treatments. c. Given H2CO3 and CO2 values, the pH can be computed. d. It allows validation of the reported values on a blood gas report. ANS: D What drives the bicarbonate buffer systems enormous ability to buffer acids? a. The fact that H2CO3 is a strong buffer b. The Henderson-Hasselbalch equation c. The large amounts of 2,3-DPG in red blood cells d. Ventilation continually removing CO2 from system ANS: A Of the nonbicarbonate buffer systems, which one is the most important? a. Hemoglobin b. Inorganic phosphates c. Organic phosphates d. Plasma proteins ANS: B Which of the following systems is primarily responsible for the buffering of fixed acids? a. Ammonia b. HCO3- c. Hb d. Phosphate ANS: A Which of the following acts as the "first-line" or immediate defense against the accumulation of H+ ions? a. Blood buffer system b. GI tract c. Renal system d. Respiratory system ANS: B Which of the following organ systems assist in acid excretion? 1. Kidneys 2. Liver 3. Lungs a. 3 only b. 1 and 3 only c. 2 only d. 1, 2, and 3 ANS: A In regard to acid excretion by the body, which of the following statements are true? 1. If one system fails, the other can help compensate. 2. The kidneys can only remove fixed acids. 3. The kidneys can quickly remove acid. 4. The lungs can quickly remove acid. a. 1, 2, and 4 only b. 2 and 3 only c. 4 only d. 1 and 4 only ANS: D The majority of the acid the body produces in a day is excreted through the lungs as CO2. What happens to the H+ ions? a. They are bound to Hb. b. They bind to phosphate. c. They form carbamino compounds. d. They bind to an OH-forming H2O. ANS: A Which organ system actually excretes H+ from the body? a. Kidneys b. Liver c. Lungs d. Spleen ANS: A If the blood PCO2 is high, the kidneys will do which of the following? a. Excrete more H+ and reabsorb more HCO3-. b. Excrete less H+ and reabsorb more HCO3-. c. Excrete less H+ and reabsorb less HCO3-. d. Excrete more H+ and reabsorb less HCO3-. ANS: A Normally which of the following occur when the kidneys eliminate H+? 1. Sodium ions (and water) are reabsorbed. 2. HCO3- is reabsorbed in proportion to the H+ excreted. 3. Bicarbonate buffer capacity is restored. a. 1, 2, and 3 b. 1 and 3 only c. 2 only d. 2 and 3 only ANS: A What is the role of carbonic anhydrase in the kidneys? a. It drives the recovery of HCO3- and excretion of H+. b. It is the catalyst for the hamburger phenomenon. c. It promotes the excretion of CO2 in the urine. d. It promotes the loss of fluids in congestive heart failure. ANS: A What effect does hyperventilation have on HCO3– recovery in the kidneys? a. Less H+ excretion, greater HCO3– loss b. No effect as these involve two independent systems. c. Vicious cycle of worsening alkalemia as hyperventilation stimulates increased HCO3– retention. d. Escalating retention of other buffer bases along with HCO3–. ANS: C What is the limiting factor for H+ excretion in the renal tubules? a. Excessive amounts of Cl- b. Excessive amounts of HCO3- c. Insufficient buffers d. Insufficient sodium ANS: D Which of the following mechanisms helps to eliminate excess H+ via the kidneys? 1. Reabsorption of HCO3- 2. Phosphate buffering 3. Ammonia buffering a. 2 and 3 only b. 1 and 3 only c. 2 only d. 1, 2, and 3 ANS: B Which of the following is/are true about the relationship between chloride (Cl-) and bicarbonate HCO3- in acid-base balance? 1. For each Cl- ion excreted into the urine, the blood gains an HCO3- ion. 2. Blood Cl- and HCO3- ion levels are reciprocally related. 3. People with chronically high CO2 tend to have low blood Cl- levels. 4. Activation of the NH3 buffer system enhances Cl- gain and HCO3 loss. a. 2 and 3 only b. 1, 2, and 3 only c. 2 only d. 2, 3, and 4 only ANS: C Which organ system maintains the normal level of HCO3- at 24 mEq/L? a. Liver b. Lung c. Renal d. Spleen ANS: B According to the Henderson-Hasselbalch equation, the pH of the blood will be normal as long as the ratio of HCO3- to dissolved CO2 is which of the following? a. 10:1 b. 20:1 c. 24:1 d. 30:1 ANS: C The numerator of the Henderson-Hasselbalch (H-H) equation (HCO3-) relates to which of the following? a. Blood concentration of nonbicarbonate buffers b. Excretion of volatile acid by the lungs c. Renal buffering and excretion of fixed acids d. Respiratory component of acid-base balance ANS: C According to the Henderson-Hasselbalch equation, the blood pH will rise (alkalemia) under which of the following conditions? 1. The buffer capacity increases. 2. The volatile acid (CO2) increases. 3. The volatile acid (CO2) decreases. 4. The buffer capacity decreases. a. 1 only b. 3 only c. 1 and 3 only d. 2 and 4 only ANS: D When does a state of alkalemia exist? 1. The HCO3-/CO2 ratio exceeds 20:1. 2. The blood pH exceeds 7.45. 3. The blood PCO2 exceeds 54 mm Hg. a. 2 and 3 only b. 1, 2, and 3 c. 3 only d. 1 and 2 only ANS: C What is the primary chemical event in respiratory acidosis? a. Decrease in blood CO2 levels b. Decrease in blood HCO3- levels c. Increase in blood CO2 levels d. Increase in blood HCO3- levels ANS: D What is the primary chemical event in metabolic alkalosis? a. Decrease in blood CO2 levels b. Decrease in blood HCO3- levels c. Increase in blood CO2 levels d. Increase in blood HCO3- levels ANS: B What is a normal response of the body to a failure in one component of the acid-base regulatory mechanism? a. Autoregulation b. Compensation c. Correction d. Homeostasis ANS: D Compensation for respiratory acidosis occurs through which of the following? a. Decrease in blood CO2 levels b. Decrease in blood HCO3- levels c. Increase in blood CO2 levels d. Increase in blood HCO3- levels ANS: B Compensation for metabolic acidosis occurs through which of the following? a. Increase in blood CO2 levels b. Decrease in blood CO2 levels c. Decrease in blood HCO3- levels d. Increase in blood HCO3- levels ANS: C A patient has a bicarbonate concentration of 36 mEq and a PCO2 of 60 mm Hg. What is the approximate pH? a. 7.2 b. 7.3 c. 7.4 d. 7.5 ANS: A Which of the following accurately describes compensation for acid-base disorders? a. Kidneys take hours to days to compensate for respiratory disorders. b. Lungs take hours to days to compensate for metabolic disorders. c. Renal compensation is always complete. d. Respiratory compensation is always complete. ANS: B A patient with a measured plasma HCO3- concentration of 24 mmol/L has an episode of acute hypoventilation, with the PCO2 rising from 40 to 70 mm Hg. What do you predict will happen acutely to the plasma HCO3- concentration? a. HCO3- will remain unchanged. b. HCO3- will rise to approximately 27 to 28 mmol/L. c. HCO3- will fall to approximately 20 to 21 mmol/L. d. HCO3- will rise to approximately 54 to 55 mmol/L. ANS: B A patient has a pH of 7.49. How would you describe this? a. Acidemia b. Alkalemia c. Not sufficient information to determine d. Normal acid-base status ANS: C An increase in the H+ ion concentration [H+] of the blood due only to an increase in the arterial PCO2 (hypercapnia) best describes which of the following? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis ANS: D An ABG result shows the pH to be 7.56 and the HCO3- to be 23 mEq/L. Which of the following is the most likely disorder? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis ANS: A An ABG result shows pH of 7.35, PaCO2 of 30 mm Hg, and HCO3- of 18 mEq/L. Which of the following is the patient's most likely primary disorder? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis ANS: A An ABG result shows pH of 7.35, PaCO2 of 30 mm Hg, and HCO3- of 18 mEq/L. What compensatory measure has the body taken to at least partially compensate for the acid-base disorder? a. Blown off CO2 b. Retained HCO3- c. Retained H+ d. Not enough information to determine ANS: A Which of the following clinical findings would you expect in a fully compensated respiratory acidosis? 1. Elevated HCO3- 2. pH below 7.35 3. pH between 7.35 and 7.39 4. Elevated PO2 a. 1 and 3 only b. 2 and 3 only c. 2 and 4 only d. 1, 3, and 4 only ANS: A Causes of respiratory acidosis in patients with normal lungs include which of the following? 1. Neuromuscular disorders 2. Spinal cord trauma 3. Anesthesia 4. Use of incentive spirometry a. 1, 2, and 3 only b. 4 only c. 2, 3, and 4 only d. 1 and 3 only ANS: B In the face of uncompensated respiratory acidosis, which of the following blood gas abnormalities would you expect to encounter? 1. Decreased pH 2. Increased HCO3- 3. Increased PCO2 4. Increased pH a. 1, 2, and 4 only b. 1 and 3 only c. 3 only d. 2, 3, and 4 only ANS: B How is acute respiratory acidosis accomplished? a. By increasing HCO3- reabsorption b. By increasing alveolar ventilation c. By decreasing HCO3- reabsorption d. By decreasing alveolar ventilation ANS: D A decrease in the H+ ion concentration [H+] of the blood caused by a low PaCO2 best describes which of the following? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis ANS: C What is the most common cause of respiratory alkalosis? a. Anxiety b. Central nervous system depression c. Hypoxemia d. Pain ANS: B Which of the following are potential causes of respiratory alkalosis? 1. Anxiety 2. Central nervous system depression 3. Hypoxemia 4. Pain a. 1, 2, and 3 only b. 1, 3, and 4 only c. 1 and 4 only d. 1, 2, 3, and 4 ANS: B What condition or treatment could cause iatrogenic respiratory alkalosis? a. Central nervous system stimulation b. Mechanical hyperventilation c. Severe hypoxemia d. Vagal stimulation ANS: B Which of the following are signs and symptoms of acute respiratory alkalosis? 1. Convulsions 2. Depressed reflexes 3. Dizziness 4. Paresthesia a. 1, 2, and 4 only b. 1, 3, and 4 only c. 2 and 4 only d. 1, 2, 3, and 4 ANS: B Compensation for respiratory alkalosis occurs through which of the following? a. Renal excretion of H+ b. Renal excretion of HCO3- c. Renal excretion of NH4+ d. Renal reabsorption of HCO3- ANS: D In a patient with partially compensated respiratory alkalosis, which of the following blood gas abnormalities would you expect to encounter? 1. Decreased pH 2. Decreased HCO3- 3. Decreased PCO2 4. Increased pH a. 1, 2, and 4 b. 1 and 3 c. 3 only d. 2, 3, and 4 ANS: B A patient who has fully compensated respiratory acidosis becomes severely hypoxic. If her lungs are not too severely compromised, what might her gases now appear to be? a. Fully compensated metabolic acidosis b. Fully compensated metabolic alkalosis c. Fully compensated respiratory alkalosis d. No change ANS: D Metabolic acidosis may be caused by: 1. an increase in fixed (nonvolatile) acids. 2. an increase in blood carbon dioxide (CO2). 3. excessive loss of bicarbonate (HCO3-). a. 1 only b. 1 and 2 only c. 1, 2, and 3 d. 1 and 3 only ANS: C What is a normal anion gap range? a. 3 to 5 mEq/L b. 6 to 8 mEq/L c. 9 to 14 mEq/L d. 24 to 26 mEq/L ANS: B A patient has an anion gap of 21 mEq/L. Based on this information, what can you conclude? 1. There is an abnormal excess of unmeasured anions in the plasma. 2. The patient probably has metabolic acidosis. 3. The concentration of fixed acids is decreased. a. 2 only b. 1 and 2 only c. 1 and 3 only d. 3 only ANS: A What explains the lack of an increased anion gap seen in metabolic acidosis caused by HCO3- loss? a. For each HCO3- ion lost, a Cl- ion is reabsorbed by the kidney. b. For each HCO3- ion lost, the body produces another to replace it. c. HCO3- is not a measured anion, so its loss does not affect the anion gap. d. Replacement of HCO3- occurs by ammonia ions which are also anions. ANS: C What are some causes of metabolic acidosis with an increased anion gap? 1. Diarrhea 2. Ketoacidosis 3. Lactic acidosis 4. Renal failure a. 2 and 3 only b. 2 and 4 only c. 2, 3, and 4 only d. 1, 3, and 4 only ANS: B Which of the following is/are cause(s) of hyperchloremic metabolic acidosis? 1. Hyperalimentation 2. Methanol intoxication 3. Severe diarrhea 4. NH4Cl administration a. 2 only b. 1 and 4 only c. 1, 3, and 4 only d. 1, 2, 3, and 4 ANS: B What is the main compensatory mechanism for metabolic acidosis? a. Excretion of HCO3- b. Hyperventilation c. Hypoventilation d. Retention of CO2 ANS: A In a patient with Kussmaul's respirations, what acid-base disturbance would you expect to see? a. Metabolic acidosis b. Metabolic alkalosis c. Respiratory acidosis d. Respiratory alkalosis ANS: D What is the treatment for severe metabolic acidosis? a. Charcoal b. Insulin c. Glucose d. NaHCO3- infusion ANS: A Primary metabolic alkalosis is associated with which of the following? a. Gain of buffer base b. Gain in fixed acids c. Low blood CO2 levels d. Diabetic crisis ANS: A Which of the following is/are cause(s) of metabolic alkalosis? 1. Diuretics 2. Hyperkalemia 3. Hypochloremia 4. Vomiting a. 1, 3, and 4 only b. 2 and 3 only c. 1, 2, and 4 only d. 2 only ANS: A What would be an example of an iatrogenic cause of metabolic alkalosis? a. Gastric suction b. High-salt diet c. Discontinuing the patient's diuretics d. Vomiting ANS: D What is the kidneys' most important function? a. Acid-base balance b. Chloride maintenance c. HCO3- maintenance d. Sodium maintenance ANS: B What compensates for a metabolic alkalosis? a. Hyperventilation b. Hypoventilation c. Renal excretion of HCO3- d. Renal retention of H+ ANS: A Based on the following ABG results, what is the most likely acid-base diagnosis? pH = 7.43, PCO2 = 39 mm Hg, HCO3- = 25.1 mEq/L a. Acid-base status within normal limits b. Fully compensated metabolic acidosis c. Fully compensated respiratory alkalosis d. Partially compensated metabolic acidosis ANS: A Based on the following ABG results, what is the most likely acid-base diagnosis? pH = 7.62, PCO2 = 41 mm Hg, HCO3- = 40.9 mEq/L a. Acute (uncompensated) metabolic alkalosis b. Acute (uncompensated) respiratory alkalosis c. Fully compensated metabolic alkalosis d. Partially compensated metabolic alkalosis ANS: C Based on the following ABG results, what is the most likely acid-base diagnosis? pH = 7.43, PCO2 = 20 mm Hg, HCO3- = 12.6 mEq/L a. Acute (uncompensated) respiratory alkalosis b. Fully compensated metabolic acidosis c. Fully compensated respiratory alkalosis d. Partially compensated respiratory alkalosis ANS: C Based on the following ABG results, what is the most likely acid-base diagnosis? pH = 6.89, PCO2 = 24 mm Hg, HCO3- = 4.7 mEq/L a. Acute (uncompensated) metabolic acidosis b. Acute (uncompensated) respiratory acidosis c. Partially compensated metabolic acidosis d. Partially compensated respiratory acidosis ANS: A Based on the following ABG results, what is the most likely acid-base diagnosis? pH = 7.08, PCO2 = 39 mm Hg, HCO3- = 11.8 mEq/L a. Acute metabolic acidosis b. Acute respiratory acidosis c. Partially compensated metabolic acidosis d. Partially compensated respiratory acidosis ANS: B Based on the following ABG results, what is the most likely acid-base diagnosis? pH = 7.28, PCO2 = 53 mm Hg, HCO3- = 25.8 mEq/L a. Acute metabolic acidosis b. Acute respiratory acidosis c. Partially compensated metabolic acidosis d. Partially compensated respiratory acidosis ANS: B Based on the following ABG results, what is the most likely acid-base diagnosis? pH = 7.38, PCO2 = 21 mm Hg, HCO3- = 11.7 mEq/L a. Acute metabolic acidosis b. Fully compensated metabolic acidosis c. Partially compensated metabolic acidosis d. Fully compensated respiratory alkalosis ANS: C Based on the following ABG results, what is the most likely acid-base diagnosis? pH = 7.35, PCO2 = 68 mm Hg, HCO3- = 34.3 mEq/L a. Acute respiratory acidosis b. Combined metabolic and respiratory acidosis c. Fully compensated respiratory acidosis d. Fully compensated metabolic alkalosis ANS: D Correction of metabolic alkalosis may involve which of the following? 1. Restoring normal fluid volume 2. Administering acidifying agents 3. Restoring normal K+ and Cl− levels a. 3 only b. 1 and 2 only c. 2 and 3 only d. 1, 2, and 3 ANS: D In order to eliminate the influence of PCO2 changes on plasma HCO3- concentrations, what additional measures of the metabolic component of acid-base balance can be used? a. HCO3- b. Hemoglobin content c. Henderson-Hasselbalch equation d. Standard bicarbonate