Chemistry - Acid-base, Blood gases and Electrolytes

35. Which statement best describes the relationship between dietary iron and iron absorption in a healthy individual? A. Only a small percentage of dietary iron is absorbed and used. B. All dietary iron is needed for hemoglobin synthesis and therefore absorbed. C. Most people need to take dietary iron supplements to meet their needs for iron. D. All dietary iron is absorbed and excess is stored.

A

38. A hospitalized patient has a decreased serum copper level and increased urine copper level. This is MOST consistent with: A. Wilson's disease B. Addison's disease C. Parathyroid disease D. Not clinically significant

A

65. Iontophoresis is a technique used in the diagnosis of: A. Phenylketonuria B. Cystic fibrosis C. Pernicious anemia D. Addison's disease

B

49. What changes in potassium and sodium serum results may occur with diuretic use? A. Decrease in both. B. Increase in both. C. Increase in potassium and decrease in sodium. D. Decrease in potassium and increase in sodium

A

57. What is the formula for calculating transferrin saturation (TS)? A. (Serum iron/TIBC) X 100 B. (Serum ferritin/TIBC) X 100 C. TIBC/serum iron D. Serum iron/serum ferritin

A

62. What would you expect the serum iron (SI) and total iron binding capacity (TIBC) to be in a person with hereditary hemochromatosis (HH)? A. Increased SI and decreased TIBC B. Decreased SI and decreased TIBC C. Decreased SI and increased TIBC D. Increased SI and increased TIBC

A

17. MOST of the carbon dioxide present in the blood is in the form of: A. Bicarbonate B. Carbonate C. Carbonic acid D. Dissolved CO2

A

1. pH alteration of normal blood in a closed vessel standing at 37oC for 1 hour is approximately: A. 0.01 to 0.02 pH units B. 0.02 to 0.04 pH units C. 0.04 to 0.08 pH units D. 0.08 to 0.12 pH units

C

13. Patients who develop severe sepsis or septic shock commonly have __________ plasma lactate values. A. Decreased B. Normal C. Increased D. Markedly decreased

C

2. Metabolic acidosis is characterized by: A. Increased pCO2 B. Hypoventilation C. Low pH D. High pH

C

15. Respiratory acidosis is associated with: A. Normal pH B. High pH C. Decreased pCO2 D. Increased pCO2

D

64. 8-Hydroxyquinoline and Ortho-Cresolphthalein complexone (CPC) reagent is commonly used in the determination of: A. Phosphorus B. Magnesium C. Chloride D. Calcium

D

68. All of the following variables related to the collection of blood may falsely increase the potassium level EXCEPT? A. Drawing a purple-top EDTA tube prior to a red-top tube. B. Mixing the blood collection tube aggressively. C. Pouring some sample from a purple-top EDTA tube into a red-top tube to make up for low collection volume. D. Using a 21 G needle with a 10 mL collection tube.

D

70. When a patient is suspected of intoxication, what would you expect the osmol gap to be? A. Slightly decreased B. Normal C. Extremely decreased D. Increased

D

71. Which of the following contributes most to serum osmolality: A. Magnesium B. Albumin C. Potassium D. Sodium

D

8. Which of the following is a cause of metabolic alkalosis? A. Late stage of Salicylate poisoning B. Uncontrolled diabetes mellitus C. Renal failure D. Excessive vomiting

D

9. Select the equation which is used to determine the pH of a solution containing a weak acid and its salt. A. Van Deemter equation B. Van Slyke equation C. Nernst equation D. Henderson-Hasselbalch equation

D

66. An automated method for measuring chloride which generates silver ions in the reaction is called: A. Amperiometric-coulometric titration B. Potentiometry C. Chromatography D. Polarography

A

6. What is the term used to describe inadequate blood supply that decreases availability of oxygen to the myocardium? A. Acute myocardial infarction (AMI) B. Angina C. Congestive heart failure (CHF) D. Myocardial ischemia

D

14. Which one of the following is the correct definition of isoelectric point (pI)? A. Buffer formation of a positively charged ionic cloud that can affect the migration of the negative ionic cloud of the sample B. The ability of a molecule to have both negatively and positively charged groups C. The pH where a molecule has a net charge of zero D. The movement of charged particles in an electrical field

C

55. The measurement of sodium and chloride in sweat is the most useful test for the diagnosis of what condition/disease? A. Steatorrhea B. Direct determination of the exocrine secretory capacity of the pancreas. C. Cystic fibrosis D. Zollinger-Ellison syndrome

C

59. Which three hormones are known to regulate serum Ca2+ by changing their secretion rate in response to changes in ionized Ca2+? A. TSH, vitamin A & calcitonin B. T4, vitamin B12 & calcitonin C. PTH, vitamin D & calcitonin D. T3, vitamin E & calcitonin

C

10. A young man is experiencing difficult breathing after fainting. The physician orders an arterial blood gas analysis which shows the following results: pH = 7.25 pCO2 = 62 mmHg pO2 = 70 mmHg HCO3- = 23 mmol/L Which condition is most likely afflicting this patient? A. Metabolic alkalosis B. Metabolic acidosis C. Respiratory alkalosis D. Respiratory acidosis

D

21. Which of the following additives should be used for the collection of a sample for blood gas analysis? A. Sodium citrate B. EDTA C. Sodium oxalate D. Heparin

D

5. Which of the following is TRUE of a fully compensated metabolic acidosis? A. pH will be decreased without a decrease in pCO2 B. pH will be decreased with a decrease in pCO2 C. pH will be decreased with an increase in pCO2 D. pH will be normal with a decrease in pCO2

D

50. Which of the following will give the best overall picture of a patient's iron stores: A. Albumin B. Transferrin C. Haptoglobin D. Ferritin

D

69. The selectivity of an ion-selective electrode is determined by the: A. Properties of the membrane used B. Magnitude of the potential across the membrane C. The size of the membrane used D. Neural potential of the membrane

A

72. In which of the following condition(s) would an increased serum osmolality be an expected finding? A. Increased arginine vasopressin hormone (AVP formerly ADH) secretion B. Diabetes insipidus C. Hyponatremia D. Acute myocardial infarction

B

74. A patient's electrolyte results are the following: Sodium = 145 mmol/L Chloride = 113 mmol/L Bicarbonate = 24 mmol/L Calculate the anion gap for this patient and choose the correct answer below. A. 32 mmol/L B. 8 mmol/L C. 27.7 mmol/L D. 3.7 mmol/L

B

42. It is important to specify if a blood specimen is a capillary specimen rather than a venous specimen. How will the following laboratory results be affected if a capillary specimen is tested? A. Potassium, calcium, and total protein are lower in capillary specimens, where glucose is typically higher than in venous blood. B. Potassium, calcium, and total protein are higher in capillary specimens, where glucose is typically lower than in venous blood. C. Potassium and total protein are lower in capillary specimens, where glucose and calcium are typically higher than in venous blood. D. Potassium and total protein are higher in capillary specimens, where glucose and calcium are typically lower than in venous blood.

A

56. What percentage of dietary iron is normally absorbed daily? A. 5% to 15% B. 25% to 35% C. 50% to 75% D. 75% to 100%

A

12. A 14-year-old male was taken to the emergency room in a coma by his school nurse. He had lost 15 pounds in 3 months. His teacher said he was always thirsty and that was he spent a lot of time running between the water fountain and the bathroom. Considering the patient's results and symptoms, what could be the cause for the osmolality result, and increased thirst? Results: pH = 7.11 (7.35-7.45) pCO2 = 20 mm Hg (35-45 mm Hg) Glucose 1050 mg/dL (60-110 mg/dL) Serum osmolality 385 mOsm/Kg (275-295 mOsm/Kg) Urine ketone strongly positive (negative) Urine glucose strongly positive (negative) *Reference ranges in ( ) A. Because the patient is in a coma, it has been a prolonged period since he has eaten or drank water. B. The increased glucose level causes a more concentrated extracellular solution, stimulating the thirst center of the hypothalamus. C. The increased glucose level causes water to go inside the cell to equilibrate with the extracellular fluid. D. None of the above

B

23.A 46-year-old woman was admitted to the hospital through the emergency room after having a bout of severe diarrhea for 3 days along with headaches, muscle aches, shortness of breath, and an increased heart rate. Blood gas measurements were ordered by her concerned physician. The results showed the following: pH = 7.30 pCO2 = 32 mm Hg HCO3- = 15 mmol/L pO2 = 93 mmol/L What acid base disorder is most consistent with this patient's results and symptoms? A. Respiratory acidosis B. Respiratory alkalosis C. Metabolic acidosis D. Metabolic alkalosis

C

24. A 56-year old female was taken to the emergency room in a coma by her employer's nurse. She had lost 35 pounds in 3 months; she was always thirsty; drinking a lot of water and running to the bathroom. The following are her laboratory results: Results: (indicates reference range) pH: 7.11 (7.35-7.45) pCO2: 21 mm Hg (35-45 mm Hg) Glucose: 950 mg/dL (60-110 mg/dL) Serum osmolality: 365 mOsm/Kg (275-295 mOsm/Kg) Urine ketone: strongly positive (negative) Urine glucose: strongly positive (negative) What is the MOST likely cause of this patient's symptoms? A. Gestational diabetes B. Diabetes insipidus C. Insulin dependent diabetes mellitus D. Type II diabetes mellitus

C

30. In healthy individuals, calcitonin is synthesized by which cells in the body? A. Hepatocytes B. Leukocytes C. Thyroid C cells D. Red blood cells

C

33. Which of the following methods would be employed to collect sweat for chloride analysis: A. Electrophoresis B. Counter electrophoresis C. Iontophoresis D. Isoelectric focusing

C

37. Which of the following is considered a cause of hypomagnesemia (decreased levels of magnesium in the blood)? A. Hypothyroidism B. Hypoaldosteronism C. Pancreatitis D. Bone carcinoma

C

4. A three-year-old boy was brought unconscious to the emergency room. Arterial blood gas results were as follows: pH = 7.07pCO2 = 90 mm HgHCO3- = 23 mmol/L This patient is most likely suffering from: A. Metabolic alkalosis B. Metabolic acidosis C. Respiratory acidosis D. Respiratory alkalosis

C

40. What drug may be used to decrease iron levels in patients with iron overload? A. Desferrioxamine B. Cobalamin C. Antibiotics D. Eculizumab

A

16. What is the term used to describe cardiac tissue death due to lack of oxygen caused by obstruction of circulation? A. Acute myocardial infarction (AMI) B. Angina C. Congestive heart failure (CHF) D. Myocardial ischemia

A

73. A patient has the following serum results: Na = 130 mEq/L K = 4.9 mEq/L Cl = 107 mEq/L Glucose = 300 mg/dL BUN = 18 mg/dL Creatinine = 1.1 mg/dL Which osmolality result is consistent with these results?. A. 240 mosmol/kg B. 251 mosmol/kg C. 281 mosmol/kg D. 293 mosmol/kg

C

31. All of the following are causes of hypernatremia EXCEPT: A. Excess water loss B. Low aldosterone production C. Decreased water intake D. Increased sodium intake or retention

B

32. All of the following anticoagulants will produce a significant effect on calcium levels in plasma, EXCEPT? A. EDTA B. Heparin C. Oxalates D. Citrates

B

34. Total iron-binding capacity measures the serum iron transporting capacity of: A. Hemoglobin B. Transferrin C. Ferritin D. Ceruloplasmin

B

22. The following results were obtained on arterial blood: pH = 7.51 pCO2= 49 mm Hg HCO3- = 38.7 mmol/L pO2= 85 mm Hg These results are compatible with: A. Metabolic acidosis B. Respiratory acidosis C. Metabolic alkalosis D. Respiratory alkalosis

C

43. In blood, bicarbonate leaves the red blood cell and enters the plasma through an exchange mechanism with: A. Sodium B. Potassium C. Chloride D. Phosphorus

C

45. What is the term used to describe a clinical syndrome caused by heart disease, represented by abnormal sodium and water retention and breathlessness, usually resulting in edema? A. Acute myocardial infarction (AMI) B. Angina C. Congestive heart failure (CHF) D. Myocardial ischemia

C

51. All of the following analytes would be significantly increased in a plasma sample as a result of hemolysis, EXCEPT? A. Potassium B. LDH C. Sodium D. AST

C

67. Which of the following would most likely occur as the result of hemodilution? A. Low serum electrolyte values B. High serum electrolyte values C. Increased anion gap D. Electrolyte concentrations would remain the same

A

44. Which of the following are terms used to describe storage pool iron? A. Hemosiderin and myoglobin B. Ferritin and hemosiderin C. Hemopectin and hemoglobin D. Apoferritin and transferrin

B

48. The parathyroid hormone (PTH) is important in the regulation of: A. Iodine and bromine B. Calcium and phosphate C. Acid and alkaline phosphatase D. Zinc and magnesium

B

53. Blood lactate concentration is an indicator of impaired circulation and tissue oxygenation in critically ill patients. If circulation and tissue oxygenation are impaired: A. Blood lactate concentration will decrease below the lower end of the established reference range. B. Blood lactate concentration will increase. C. Blood lactate will not be affected. D. Blood lactate will be slightly decreased.

B

54. Which of the following is the most common cause of hyperkalemia in hospitalized patients? A. Cellular injury B. Therapeutic potassium replacement C. Chemotherapy D. Leukemia

B

60. Zinc deficiency in the elderly is often caused by: A. Decreased intake and absorption B. Decreased intake and excretion C. Increased intake and excretion D. Increased excretion and decreased absorption

A

46. Which of the following contributes most to serum osmolality: A. Magnesium B. Albumin C. Potassium D. Sodium

D

58. Ionized calcium is currently most commonly measured using which of the following method? A. Flame photometry B. Color complex formation between calcium and o-cresolphthalein C. Atomic absorption D. Calcium ion selective electrodes

D

39. Which one of the following statements about serum ferritin is true? A. It is a sensitive indicator of iron deficiency B. Elevation of serum ferritin is specific for hemochromatosis C. It is synonymous with transferrin D. It is a better test for bone marrow iron stores than a Prussian blue stain of marrow particles

A

11. Which of the following statements is TRUE with respect to uncompensated metabolic alkalosis? A. pH will be elevated without an elevation of pCO2 B. pH will be elevated with an elevation of pCO2 C. pH will be elevated with a decrease in pCO2 D. pH will be normal with an elevation of pCO2

A

26. Calcium and phosphorus levels were determined for a 4-year-old patient as follows: Ca - 14 mg/dL Phosphorus - 1 mg/dL These results are MOST compatible with: A. Hyperparathyroidism B. Renal failure C. Rickets D. Hypervitaminosis

A

28. Which of the following electrolytes is most likely to be spuriously elevated in a hemolyzed specimen? A. Sodium B. Potassium C. Chloride D. BUN

B

52. A serum specimen for potassium testing is collected in a red top tube without a gel separator barrier. If testing is delayed by a few hours, how should the specimen be handled? A. Discard the specimen and recollect right before testing is available again. B. Discard the specimen and recollect in a gel separator tube. C. The specimen should be centrifuged as soon as it clotted and serum should be transferred to another tube. D. There is no special handling procedure for this specimen.

C

25. When iontophoresis is used to collect sweat for chloride analysis, pilocarpine is used to: A. Clean the skin area B. Complex with chloride C. Stimulate nervous system D. Induce the sweat secretion

D

29. A liquid ion-exchange membrane electrode using the antibiotic valinomycin is MOST selective for: A. Sodium B. Glucose C. Chloride D. Potassium

D

18. Which values would be expected with metabolic alkalosis? A. Elevated pH, increased bicarbonate, normal PCO2 B. Elevated pH, decreased bicarbonate, normal PCO2 C. Lowered pH, normal bicarbonate, decreased PCO2 D. Increased pH, normal bicarbonate, increased PCO2

A

27. Which of the following would you find in a primary hyperparathyroidism case? A. Elevated serum calcium and decreased serum phosphorus B. Elevated serum calcium and elevated serum phosphorus C. Decreased serum calcium and decreased serum phosphorus D. Decreased serum calcium and increased serum phosphorus

A

41. What is the cause of iron overload in hereditary hemochromatosis? A. Absorption of excessive amounts of iron in the small intestine B. Ingestion of excessive amounts of iron from diet or supplements C. Inability of the body to excrete normal amounts of dietary iron D. Failure of developing red blood cells to incorporate iron into protoporphyrin IX

A

47. In which of the following condition(s) would an increased serum osmolality be an expected finding? A. Dehydration and Diabetes insipidus B. Hyponatremia and Dehydration C. Increased arginine vasopressin hormone (AVP formerly ADH) secretion and in Hyponatremia D. AVP and Diabetes insipidus

A

63. Ion selective electrodes, for pH determinations, are called selective rather than specific because they actually measure the: A. Activity of one ion only B. Concentration of one ion C. Activity of one ion much more than other ions present D. Concentration and activity of one ion only

C

19. What is the term used to describe chest pain caused by inadequate supply of oxygen to heart myocardium? A. Acute myocardial infarction (AMI) B. Angina C. Congestive heart failure (CHF) D. Myocardial ischemia

B

20. Hydrogen ion concentration (pH) in blood is usually determined by means of which of the following electrodes? A. Silver B. Glass C. Platinum D. Gold

B

61. Which of the following conditions should be suspected if a healthy patient presents with an elevated potassium level while all other chemistry results are normal? A. The sample is turbid. B. The sample is hemolyzed. C. The sample is clotted. D. The sample is lipemic.

B

7. When the body compensates for a respiratory or metabolic disorder, the MAIN goal is to achieve: A. Correct carbonic acid level, since it is the most important system in the body B. A normal pH C. Normal pO2 and pCO2 for normal respiration D. Correct bicarbonate level, since it is the most important system in the body

B

3. What condition is indicated by the following arterial blood gas results? Bicarbonate = 32 mmol/L (Normal = 22 - 29 mmol/L) pCO2 = 65 mm Hg (Normal = 35 - 45 mmHg) pH = 7.28 (normal = 7.35 - 7.45) A. Healthy condition B. Uncompensated metabolic acidosis C. Compensated metabolic acidosis D. Uncompensated respiratory acidosis

D

36. Which of the following forms of calcium is biologically active: A. Protein-bound calcium B. Non-ionized calcium C. Calcium carbonate D. Free ionized calcium

D