Lab values

Question 1

You are transporting a patient following a near drowning/submersion injury. The most recent serum magnesium level is 1.0 mEq/L. Based on this, you suspect which of the following?
Choose one answer.
A. The patient received 2 mg of IV atropine during resuscitation.
B. The patient underwent prolonged resuscitation after submersion in his home pool.
C. The patient sustained the submersion injury in sea water and aspirated.
D. The patient received 4 units of packed red blood cells during resuscitation.

Answer 1

C. The patient sustained the submersion injury in sea water and aspirated.

Question 2

Blood, urine, and sputum cultures are primarily used to determine which of the following?
Choose one answer.
	A. the presence of microorganisms 
	B. the pH of body fluids 
	C. the presence of ketone bodies 
	D. the presence of anaerobic metabolism

Answer 2

A. the presence of microorganisms

Question 3

Your patient had a computed tomography (CT) scan at the transferring facility. Which of the following statements is TRUE regarding CT scans?
Choose one answer.
A. A patient on a mechanical ventilator should not undergo CT scanning due to potential interference with the scanner’s field.
B. Patients with implanted medical devices cannot undergo CT scans.
C. CT scanning provides cross-sectional images of the body part in question.
D. CT scanning uses magnetic radiation.

Answer 3

C. CT scanning provides cross-sectional images of the body part in question. Correct

Question 4

You are caring for a 30-year-old male who has sustained a significant crush injury. On review of his laboratory studies, you note that his serum myoglobin is 210 μg/L. Based on your understanding of myoglobin, you know that this number is most likely explained by which of the following statements?
Choose one answer.
A. The patient is in compensated hypovolemia shock.
B. Having sustained a crush injury would possibly cause large quantities of myoglobin to be released from the damaged skeletal muscle tissue.
C. Myoglobin is a protein that is released specifically during times of cardiac stress or ischemia.
D. Myoglobin is present in cardiac, skeletal, and smooth muscle tissue.

Answer 4

B. Having sustained a crush injury would possibly cause large quantities of myoglobin to be released from the damaged skeletal muscle tissue.

Question 5

While caring for a 50-year-old male who has just been diagnosed with an acute myocardial infarction, you notice that his creatine kinase-MB (CK-MB) levels are elevated outside of the normal range. You know that the CK-MB level may be elevated for reasons other than an acute myocardial infarction. Which of the following statements best explains the usefulness of the CK-MB level in diagnosing his condition?
Choose one answer.
A. The CK-MB isoenzyme is not a very sensitive test.
B. The CK-MB isoenzyme is a highly specific test.
C. The CK-MB isoenzyme is a precise test.
D. The CK-MB isoenzyme is a somewhat reliable test.

Answer 5

A. The CK-MB isoenzyme is not a very sensitive test.

Question 6

Which of the following is considered the respiratory component of the ABG values?
Choose one answer.
	A. HCO3 
	B. pH 
	C. PaO2 
	D. PaCO2

Answer 6

D. PaCO2

Question 7

Your patient has sustained a myocardial infarction. In addition to the 12-lead ECG showing significant ST elevations in II, III, and AVF, which of the following specifically indicates myocardial damage?
Choose one answer.
A. a CK-MB level of 124 ng/mL
B. a lactate dehydrogenase (LDH) level of 24 U/L
C. a troponin value of 0.02 ng/mL
D. a troponin value of 0.12 ng/mL

Answer 7

D. a troponin value of 0.12 ng/mL

Question 8

The percentage of potential oxygen-binding sites on hemoglobin that are occupied by oxygen molecules is reflected by which of the following values?
Choose one answer.
	A. hemoglobin  	
	B. SaO2 
	C. FiO2 
	D. PaO2

Answer 8

B. SaO2

Question 9

In a patient suffering from diabetes insipidus, which of the following urine specific gravity values would you most likely expect to see?
Choose one answer.
	A. 1.025 
	B. 1.041
	C. 1.001
	D. 1.004

Answer 9

C. 1.001

Question 10

You suspect that your ventilated patient has developed bacterial pneumonia. Sputum cultures have been obtained, and culture and sensitivity testing have been ordered. The purpose of sensitivity testing is:
Choose one answer.
A. to determine if the patient has a potential for an anaphylactic reaction.
B. to determine what antibiotic will best treat the infection.
C. to determine the presence of bacteria in the pulmonary tissue.
D. to determine if the pneumonia was caused by the ventilator.

Answer 10

B. to determine what antibiotic will best treat the infection.

Question 11

Your patient has a history of chronic hypertension, which has been poorly treated in the past. You suspect that the patient may be experiencing renal failure secondary to the essential hypertension. Which of the following is a TRUE statement regarding protein in the urine?
Choose one answer.
A. Proteinuria is always due to a renal cause.
B. In renal failure, the protein level is zero.
C. Protein in the urine has a better specificity than sensitivity for renal disease.
D. Up to 40 to 80 mg of protein may be excreted in the urine normally and is not detectable.

Answer 11

D. Up to 40 to 80 mg of protein may be excreted in the urine normally and is not detectable.

Question 12

Calcium is found in the body in which three states?
Choose one answer.
	A. dispersed, viscous, and saturated 
	B. free, chelated, and bound 
	C. saturated, chelated, and free 
	D. ionized, saturated, and free

Answer 12

B. free, chelated, and bound

Question 13

You are transporting a patient who recently sustained major crush injuries to both legs. The cardiac monitor shows peaked T waves. Which of the following laboratory potassium values most closely reflect the monitor changes?
Choose one answer.
	A. 4.7 mEq/L 
	B. 2.9 mEq/L 
	C. 5.8 mEq/L
	D. 3.8 mEq/L

Answer 13

C. 5.8 mEq/L

Question 14

A serum acetone level is drawn on a patient with diabetic ketoacidosis. You recall that this is a qualitative measurement. Based on this, which of the following test results reflect a qualitative value?
Choose one answer.
	A. Serum acetone is 23. 
	B. Serum acetone is positive.  	
	C. Serum acetone is negligible. 
	D. Serum acetone is variable.

Answer 14

B. Serum acetone is positive.

Question 15

You are transporting a trauma patient to a tertiary care facility for definitive care. Prior to transport, this patient underwent a prolonged resuscitation effort at the sending hospital. Based on the prolonged resuscitation, which of the following would be the most specific test to reflect organ perfusion?
Choose one answer.
	A. bicarbonate 
	B. alkaline phosphatase
	C. lactate
	D. serum pH

Answer 15

C. lactate

Question 16

You are caring for a 40-year-old male with severe gastrointestinal bleeding. He is to receive two units of packed red blood cells due to profound anemia. Based on your understanding of hemoglobin, which of the following statements is TRUE?
Choose one answer.
A. Hemoglobin is a measurement of the percentage of red blood cells in the circulating volume.
B. Hemoglobin levels typically elevate under periods of acute stress or sudden trauma to compensate for increased oxygenation needs.
C. A hemoglobin level of 10 g/dL is acceptable for males and females.
D. Hemoglobin is the protein responsible for carrying oxygen to the cells.

Answer 16

D. Hemoglobin is the protein responsible for carrying oxygen to the cells.

Question 17

The ability of a laboratory test to give consistently similar results each time it is run is called:
Choose one answer.
	A. reliability. 
	B. accuracy. 
	C. precision. 
	D. effectiveness.

Answer 17

C. precision.

Question 18

You are transporting a patient being treated for diabetic ketoacidosis. The patient is on the ventilator, and the most recent arterial blood gas (ABG) panel from the sending facility was pH, 7.34; PaO2, 96 mm Hg; PCO2, 43 mm Hg. Your patient is receiving an intravenous potassium drip at 10 mEq/hour and an insulin drip/continuous infusion at 6 units/hour. What lab value must be frequently reassessed during the care and transport of this patient?
Choose one answer.
	A. lactate 
	B. glucose
	C. calcium 
	D. potassium

Answer 18

B. glucose

Question 19

Your patient is being treated for diabetic ketoacidosis. The most recent chemistry panel for this patient reveals a serum potassium of 2.5 mEq/L. Based on your understanding of this potassium abnormality, which of the following is the most likely cause for this value?
Choose one answer.
A. 50% dextrose administration
B. insufficient isotonic fluid resuscitation
C. insulin administration
D. metabolic alkalosis

Answer 19

C. insulin administration

Question 20

You are caring for a patient who develops a sudden altered level of consciousness. Which of the following laboratory tests is readily available in the out-of-hospital setting and is of possible diagnostic use for this condition?
Choose one answer.
A. point-of-care cardiac biomarkers (ie, troponin)
B. urinalysis dipstick
C. point-of-care glucose
D. point-of-care brain natriuretic peptide (BNP)

Answer 20

C. point-of-care glucose

Question 21

You are transporting a seriously brain-injured patient. Review of the chemistry panel at the transferring hospital shows a serum sodium of 155 mEq/L. Which of the following statements is TRUE regarding serum sodium measurements?
Choose one answer.
A. This result may indicate overhydration.
B. This result necessitates you to prepare and administer a hypertonic saline drip.
C. The normal range for serum sodium is approximately 145 to 165 mEq/L.
D. A sodium of 155 mEq/L may be the result of overly aggressive diuresis.

Answer 21

D. A sodium of 155 mEq/L may be the result of overly aggressive diuresis.

Question 22

Your patient is suffering from profound liver failure. When reviewing the patient's laboratory values, you note that the direct bilirubin level is 2.2 mg/dL. Based on this information, you would anticipate which of the following physical findings?
Choose one answer.
	A. a body-wide petechial rash 
	B. pulmonary edema 
	C. anemia
	D. hypotension

Answer 22

C. anemia

Question 23

Which of the following statements best describes an enzyme?
Choose one answer.
A. It is a chemical substance that remains inert in human tissues.
B. It is a polar molecule that does not cross-react.
C. It is a protein that catalyzes biochemical reactions.
D. It is a molecule that is modified from its base structure.

Answer 23

C. It is a protein that catalyzes biochemical reactions.

Question 24

Osmotic pressure depends on:
Choose one answer.
A. the size of the particles in the solution. Incorrect
B. the total number of particles in the solution. Correct
C. the net ionic charge of the particulate. Incorrect
D. the number of different particle types in the solution. Incorrect

Answer 24

B. the total number of particles in the solution.

Question 25

\_\_\_\_\_\_\_ is the proportion of people without the target disorder who have a negative test result.
Choose one answer.
	A. Sensitivity 
	B. Specificity 
	C. Reliability 
	D. Accuracy

Answer 25

B. Specificity

Question 26

Which of the following is the major intracellular cation?
Choose one answer.
	A. potassium  	
	B. sodium 
	C. calcium 
	D. glucose

Answer 26

A. potassium

Question 27

Which of the following statements regarding ultrasonography is TRUE?
Choose one answer.
A. It is based on measuring sound waves as they travel through body tissues.
B. It can only be performed by a physician.
C. It is contraindicated in pregnancy.
D. It requires very little training.

Answer 27

A. It is based on measuring sound waves as they travel through body tissues.

Question 28

The physiologic measurement of osmotic pressure in humans is called:
Choose one answer.
	A. osmolality. 
	B. osmolarity. 
	C. diffusion. 
	D. concentration.

Answer 28

A. osmolality.

Question 29

You are caring for a patient who was found initially unresponsive. Which of the following laboratory values most likely represents a cause for this depressed mental state?
Choose one answer.
A. carboxyhemoglobin = 5% Incorrect
B. lithium = 1.4 mEq/L Incorrect
C. alcohol = 0.6% Correct
D. acetaminophen (Tylenol) level = 125 μg/mL

Answer 29

C. alcohol = 0.6%

Question 30

You receive a report that an ICU patient is in acute renal failure. You inquire as to the most recent ionized calcium level result. You are told that 1 hour ago it was 4.40 mg/dL. Based on your knowledge of ionized calcium, you recognize that the most serious possible complication at this time, in light of the lab value, is:
Choose one answer.
	A. serious arrhythmias. 
	B. sudden respiratory failure. 
	C. status epilepticus. 
	D. brain herniation.

Answer 30

A. serious arrhythmias.

Question 31

The diffusion of fluid across membranes is referred to as:
Choose one answer.
	A. tonicity. 
	B. osmosis. 
	C. the concentration gradient. 
	D. dieresis.

Answer 31

B. osmosis.

Question 32

While reviewing your patient’s lab values prior to transfer, you note that the hematocrit is 48%. Based on your knowledge of the hematocrit test, you know that it has a:
Choose one answer.
A. high sensitivity and high specificity.
B. high sensitivity and low specificity.
C. low sensitivity and high specificity.
D. low sensitivity and low specificity.

Answer 32

B. high sensitivity and low specificity. Correct

Question 33

Creatinine is a very reliable marker for kidney function because:
Choose one answer.
A. it can be run at the bedside, just off of a drop of blood.
B. it has a steady, predictable rate of production in the kidneys.
C. it has a narrow range of values.
D. it can be run quickly by the laboratory.

Answer 33

B. it has a steady, predictable rate of production in the kidneys.

Question 34

You are caring for a 35-year-old female who was the victim of an inhalational smoke injury during a house fire. She was intubated due to respiratory compromise. Currently, she is being ventilated with a capital tidal volume of 500 mL, a respiratory rate of 12 breaths/min, and an FiO2 of 40%. While on continuous waveform capnography, you note that her end tidal CO2 is increasing to 60 mm Hg. Which of the following statements is TRUE?
Choose one answer.
A. 60 mm Hg is a quantitative measurement.
B. 60 mm Hg is a qualitative measurement.
C. 60 mm Hg is a specific measurement.
D. 60 mm Hg is a sensitive measurement.

Answer 34

A. 60 mm Hg is a quantitative measurement.

Question 35

While caring for a burn patient in the intensive care unit, you receive a critical value for the serum potassium. The serum potassium is reported to be 7.7 mEq/L. You know that sometimes an underlying condition can cause the test to be inaccurate. Your first action in this case should be to:
Choose one answer.
A. assess the patient’s cardiovascular status. Correct
B. prepare to administer D50, insulin, and calcium. Incorrect
C. redraw and rerun the blood test. Incorrect
D. call the laboratory to ask if their analyzer is calibrated correctly. Incorrect

Answer 35

A. assess the patient’s cardiovascular status.

Question 36

While caring for your trauma patient with crush injuries, you see that his serum creatinine level is 2.3 mg/dL. Which of the following statements best accounts for this lab value?
Choose one answer.
A. Fluid resuscitation has been too aggressive.
B. This patient may also be suffering from an acetaminophen toxidrome.
C. The byproducts of the muscle tissue damage are affecting renal functioning.
D. The patient is suffering from anaerobic metabolism.

Answer 36

C. The byproducts of the muscle tissue damage are affecting renal functioning.

Question 37

Magnetic resonance imaging (MRI) testing is especially useful for diagnostic images of the spinal cord, heart, and which of the following?
Choose one answer.
	A. brain 	
	B. bladder  	
	C. pulmonary tree 
	D. upper gastrointestinal tract

Answer 37

A. brain

Question 38

Which of the following best describes an ion?
Choose one answer.
A. a molecule that carries either a positive or negative charge
B. an isotope that carries extra neutrons
C. an atom that has gained or lost electrons
D. an atom with equal numbers of protons and neutrons

Answer 38

C. an atom that has gained or lost electrons

Question 39

MRI testing uses a very strong magnetic field. Because of this, several considerations may exclude a patient from undergoing MRI testing. Which of the following patients should not receive an MRI?
Choose one answer.
A. a patient who has a central line catheter in place
B. a patient who has a Foley catheter in place
C. a patient who has received a blood transfusion
D. a patient who has an implantable defibrillator

Answer 39

D. a patient who has an implantable defibrillator

Question 40

The ability of a test to detect a particular condition is referred to as its:
Choose one answer.
	A. sensitivity.	
	B. feasibility. 
	C. reliability. 
	D. specificity.

Answer 40

A. sensitivity.

Question 41

You are caring for a patient who potentially has acute bacterial meningitis. A lumbar puncture to obtain cerebrospinal fluid (CSF) has been performed. Which of the following is an abnormal value from a CSF panel?
Choose one answer.
A. glucose = 5 mL
B. cell count = 1 white blood cell (WBC)
C. total protein = 30 mg/100mL
D. opening pressure = 100 mm H2O

Answer 41

A. glucose = 5 mL

Question 42

You are preparing to draw an ABG panel on a ventilated patient. Prior to performing the draw, you know that you will perform Allen’s test. The purpose of Allen’s test is:
Choose one answer.
A. to determine the best size needle to use during the arterial puncture.
B. to determine accurately the specific site for arterial puncture.
C. to assess for any preexisting nerve damage prior to arterial puncture.
D. to assess for a potential arterial occlusion of the radial or ulnar arteries.

Answer 42

D. to assess for a potential arterial occlusion of the radial or ulnar arteries.

Question 43

While working in the coronary care unit, you have been caring for a patient with a recent myocardial infarction who received tissue plasminogen activator (tPA) during the course of his care. You recognize that this patient is at risk for bleeding as a result of the tPA administered. Which of the following lab values most closely reflects a patient who is at risk of bleeding?
Choose one answer.
A. a bleeding time of 2 seconds
B. a prothrombin time (PT) of 28 seconds
C. an activated partial thromboplastin time (aPTT) of 30 seconds
D. an international normalized ratio (INR) of 1.1

Answer 43

B. a prothrombin time (PT) of 28 seconds

Question 44

Which of the following are the most common specimen-collection errors?
Choose one answer.
A. incorrect specimen tubes and inappropriate collection technique
B. mislabeling of specimens and incorrect specimen tubes
C. incorrect patient identification and mislabeling of specimens
D. incorrect patient identification and incorrect specimen tubes

Answer 44

C. incorrect patient identification and mislabeling of specimens

Question 45

You are preparing to draw venous blood samples on your patient. Which of the following statements reflect the correct association between blood tubes and laboratory tests?
Choose one answer.
A. The lavender tube is used for coagulation studies.
B. The red tube is used for chemistry studies.
C. The marbled tube is used for a blood bank.
D. The gray tube is used to determine the lactate level.

Answer 45

D. The gray tube is used to determine the lactate level.

Question 46

Which of the following statements most accurately describes serum CO2 levels?
Choose one answer.
A. The normal range is approximately 15 to 25 mEq/L.
B. They reflect an indirect measurement of fluid status.
C. They reflect the amount of circulating bicarbonate (HCO3–).
D. They reflect cellular anaerobic metabolism.

Answer 46

C. They reflect the amount of circulating bicarbonate (HCO3–).

Question 47

A laboratory test that is \_\_\_\_\_\_\_ conforms to the standard or true value.
Choose one answer.
	A. accurate 
	B. reliable 
	C. differential 	
	D. consistent

Answer 47

A. accurate

Question 48

Your patient has detectable hematuria on the most recent urinalysis. Some possible causes for this include neoplasms, ureterolithiasis, trauma, and:
Choose one answer.
	A. kidney obstruction. 
	B. orchitis. 
	C. prostatitis. 
	D. pyelonephritis.

Answer 48

D. pyelonephritis.

Question 49

A specific gravity of 1.150 is most likely attributable to which of the following?
Choose one answer.
A. prolonged
B. total body surface area burns greater than 25% Incorrect
C. dehydration
D. acute renal failure

Answer 49

C. dehydration

Question 50

Your patient is complaining of severe left-upper-quadrant pain, nausea, and vomiting and is moderately hypotensive. Which of the following laboratory values most closely reflects acute pancreatitis as the possible cause?
Choose one answer.
	A. hemoglobin = 12.2 g/dL 
	B. lipase = 452 U/L  	
	C. alkaline phosphatase = 109 U/L 
	D. amylase = 122 U/L

Answer 50

B. lipase = 452 U/L