Lesson Two Quiz
The Clark electrode measures which analyte?
ao2
Which of the following is TRUE regarding standard pulse oximeters? a. In the presence of dyshemoglobins, they tend to underestimate the true SaO2 b. In patient's with good perfusion, their accuracy is in the 2% to 4% range c. Their accuracy increases when the HB saturation drops below 65% to 70% d. They measure the fractional concentration of HB (O2HB to total Hb).
b
Which two electrodes are very much alike? a. Polarographic and Severinghaus b. Sanz and Severinghaus c. Sanz and Clark d. Clark and Severinghaus
b
he medication used to reverse methemoglobinemia is: a. Medium chain triglycerides b. Methylene blue c. Lidocaine d. Heparin
b
ou determine that a blood gas sample that requires analysis has been sitting in ice slush for 90 min. What should you do? a. Readjust the blood gas analyzer temperature to 0° C. b. Discard the sample and notify the appropriate clinician. c. Warm the sample to room temperature before analysis. d. Go ahead and analyze the sample (because it was on ice).
b
How is the accuracy of a blood gas analyzer determined? a. examining the repeatability of the analyzer's results b. adjusting the gain (or slope) of the instrument c. comparing the analyzer's measurements to known values d. adjusting the offset (or balance) of the instrument
c
How often should blood gas calibration verification by control media take place? a. At least one level of control media should be analyzed every 8 hours. b. At least two levels of control media should be analyzed every hour. c. At least two levels of control media should be analyzed every 8 hours. d. At least two levels of control media should be analyzed every day.
c
Statistically derived limits for internal quality control of blood gas samples are usually set at what appropriate level? a. 5 standard deviations from the mean b. 3 standard deviations from the mean c. 2 standard deviations from the mean d. 1 standard deviation from the mean
c
If you wanted to measure actual hemoglobin saturation, what type of analyzer would be needed?
cooximeter
If a patient is breathing room air and the sum of the PaO2 and the PaCO2 is less than 140 mmHg, either a measurement or reporting error has occurred (i.e. pt. is on supplemental oxygen or air in sample). true or false
false
It is possible to have a PaO2 greater than the PAO2. true or false
false
The blood gas electrodes in a blood gas analyzer are heated to 39º C to work accurately. True or false
false
The Severinghaus electrode measures which analyte?
paco2
The Sanz electrode measures which analyte?
ph
Which of the following is TRUE regarding respiratory alkalosis? a. The PaCO2 is less than 35 mmHg b. It is completely compensated if the pH is 7.52 c. An increase in HCO3 compensates for respiratory alkalosis d. It is called partially compensated if the pH is in the normal range
a
A 5-year-old patient is admitted to the emergency department with suspected smoke inhalation. To assess the oxygenation status, you would recommend: a. Arterial sample + CO-oximetry b. Arterial sample plus arterial blood gas analysis c. Standard pulse oximetry d. Transcutaneous PO2
a
A mixed metabolic acidosis and respiratory alkalosis are likely when the pH and HCO3 are low and the PaCO2 is: a. Lower than predicted b. Higher than the predicted c. Within its reference range d. 20 times the concentration.
a
An 80-year-old patient has a PaO2 of 71 mmHG. How would you describe this finding? a. Mild hypoxemia b. Severe hypoxemia c. Normal for his age d. Moderate hypoxemia
a
Before an arterial blood gas sample is obtained, the patient's clotting parameters should be evaluated because: a. Bleeding time may be prolonged if they are abnormal b. The may affect the accuracy of sample pH c. If reduced, they may hinder filling of the syringe d. The may affect the accuracy of the sample PaO2
a
Calculate the PO2 calibration value for a blood gas analyzer given the following data:PB 760 torrBlood Gas Analyzer temperature 37º C Water vapor pressure (PH2O): 47 torr0.12 O 20.05 CO 2 a. 85.56 torr b. 91.20 torr c. 12.00 torr d. 20.90 torr
a
Factors contributing to imprecision (random) errors during blood gas analysis include all of the following except: a. contaminated buffers b. statistical probability c. sample contamination d. sample mishandling
a
In performing an Allen test on a patient's left wrist before drawing an arterial sample, you note that her hand remains blanched for more than 25 seconds after releasing pressure on the ulnar artery. Which of the following actions would you take at this time? a. Repeat the test on the opposite wrist b. Insert a catheter into the brachial artery c. Report that the sample cannot be obtained d. Proceed with sampling through left radial artery
a
The RT is preparing to calibrate a blood gas analyzer. The compressed gas tanks containing the calibration gases have the following oxygen and carbon dioxide mixtures.Cylinder A Cylinder B5.0% CO2 10.0% CO212.0% O2 0.0% O2Calculate the 2 point or high point O2 and CO2 partial pressure values shown in Cylinder B. Use an atmospheric pressure of 760 torr. a. PO2 0 torr; PCO2 71.3 torr b. PO2 91.2; PCO2 38 torr c. PO2 149.73; PCO2 71.3 torr d. PO2 72.70; PCO2 35.65 torr
a
To measure actual blood O2 saturation, you would recommend: a. CO-oximetry b. Arterial blood gas c. Transcutaneous PO2 d. Pulse oximetry
a
When conducting ABG analysis in the laboratory, obvious signs of pre-analytical error include all of the following except: a. iced sample b. clotting c. gross dilution d. air bubbles
a
Which of the arterial blood gas acid-base reports represents an error? a. pH = 7.50, PaCO2 = 50 mmHg, HCO3 = 20 mmHg b. pH 7.30, PaCO2 = 60 mmHg, HCO3 = 29 mmHg c. pH = 7.40, PaCO2 = 25 mmHg, HCO3 = 15 mmol/L d. pH + 7.60, PaCO2 = 35 mmHg, HCO3 = 33 mmol/L
a
Which of the following infection control precautions would you apply when obtaining an arterial blood gas sample? a. Standard precautions plus face shield b. Contact precautions plus gown c. Airborne precautions plus N95 respirator d. Droplet precautions plus surgical mask
a
Which of the following would you expect to occur if too much heparin was used in gathering an ABG sample from a patient breathing room air? a. Decrease in PCO2 b. Decrease in PO2 c. Decrease in pH d. Increase in HCO3-
a
hich of the following causes a metabolic acidosis? a. Renal disease b. Vomiting c. Hyperventilation d. Hypokalemia
a
ossible causes of methemoglobinemia include: a. All are possible causes b. Nitrites/nitrates c. Nitric oxide d. Lidocaine/benzocaine/hurricane spraye. Nitroglycerin
a
A blood gas analyzer requires calibration containing the following gas mixture: 21% O2, 10% CO2, and 69% N2. Local barometric pressure is 750 torr and the water vapor is 47 torr. Calculate what the expected one-point (low point) calibration value should be for the PO2 electrode a. 158 torr b. 148 torr c. 47 torr d. 750 torr
b
A patient breathing 40% O2 has a markedly higher than normal P(A-a)O2, which does not improve when the O2 concentration is increased to 50%. What is the most likely cause of her hypoxemia? a. Diffusion defect b. Pulmonary shunting c. V/Q imbalance d. Hypoventilation
b
A patient's temperature is 39.4ºC (103ºF) and the PaO2 is measured at 37ºC. The measured (uncorrected) PaO2 will be: a. Dependent on the measured HCO3 b. Below the patient's true PaO2 c. Independent of the patient's temp. d. Above the patient's true PaO2
b
A pulse oximeter is being used to monitor a patient who was rescued from a fire. The SpO2 is 90%; however, the patient is unconscious and shows signs of respiratory distress. What additional test should the RT recommend? a. A CT scan b. Co-oximetry c. Hemoblobin and hematocrit levels d. Electrolyte measurement
b
An acute increase in PaCO2 of 10 to 15 mmHg causes a corresponding increase in plasma HCO3 of how much? a. 4 mmol/L b. 1 mmol/L c. 2 mmol/L d. 3 mmol/L
b
Polarographic electrodes are known as: a. Severinghaus electrodes b. Clark electrodes c. Sanz electrodes d. Glass electrodes
b
The O 2 gas of a given mixture in a cylinder used for calibration of a blood gas analyzer is 12% and the barometric pressure is 748 torr. What will be the one-point (low point) calibration for the PO2 electrode of the blood gas analyzer? a. 74.80 torr b. 84.12 torr c. 89.80 torr d. 89.76 torr
b
The best way to minimize the impact of cell metabolism on analysis of an arterial blood gas sample is to: a. Use extra heparin in the syringe b. Analyze the sample within minutes c. Immediately place the sample on dry ice d. Fully expel all air bubbles
b
To measure PCO2, blood gas analyzers use what electrode? a. Sahn b. Severinghaus c. White d. Clark
b
Which blood gas analyzer electrode uses a separate reference electrode. a. O2 b. pH c. Clark d. HCO3−
b
A blood gas analyzer measures all of the following except. a. pH b. PCO2 c. PO2 d. HCO3−
d
A patient has a measured SaO2 of 82%. What is his approximate PaO2? a. 60 mmHg b. 70 mmHg c. 80 mmHg d. 50 mmHg
d
A patient receiving mechanical ventilation requires frequent assessment of oxygenation, ventilation, and acid-base balance. Which of the following would you recommend? a. Continuous pulse oximetry b. Continuous capnography c. PtcO2?PtcCO2 monitoring d. Arterial blood gas sampling through an A-line.
d
An arterial blood gas sample is drawn for a patient breathing room air. Analysis reveals the following results:pH 7.45PaCO2 35 mmHgPaO2 155 mmHgWhich of the following best explains the results? a. Analysis of the sample was delayed for more than 60 minutes b. Too much heparin was added to the sample c. The patient was hyperventilating during the puncture d. An air bubble has contaminated the sample
d
Analysis of an arterial blood sample taken from a healthy athlete reveals a pH of 7.36, a PCO2 of 45 mm Hg, and a PO2 of 43 mm Hg. Which of the following analytic errors should you suspect? a. Exposure of the blood sample to air b. Excessive heparin in the sample c. Excessive time since sample collection d. Sample admixture with venous blood
d
Because of an extremely low PO2, you suspect that an arterial blood sample taken from a patient's brachial artery might have been contaminated with venous blood. Which of the following might help to confirm your suspicion? a. Measure the sample's actual hemoglobin saturation. b. Call the laboratory resources/staff to get the latest chemistry report. c. Inspect the sample for color and consistency. d. Cross-check the sample with an SpO2 reading.
d
Factors contributing to bias (systematic) errors during blood gas analysis include all of the following except: a. component failure b. contaminated buffers c. incorrect procedures d. statistical probability
d
A blood gas machine is actually capable of direct measurement of: I. PCO2 II. SaO 2 III. BE IV. pH
i,iv
An I-stat is an example of a point of care analyzer. (POC) true or false
true
An important question to ask before making any decisions based on blood gas results is whether the patient's condition is consistent with the results. True or false
true
Any time the PaO2 is greater than 5 times the FiO2 (oxygen concentration) the result should be suspect. true or false
true
A practitioner forgets to ice an ABG sample and leaves it at room temperature for 45 min. Which of the following parameters can you predict will increase in this sample during that period? 1. PCO2 2. pH 3. PO2
1
Which of the following Centers for Disease Control and Prevention (CDC) barrier precautions would you use when obtaining an arterial blood gas (ABG) through percutaneous puncture? 1. Gloves 2. Protective eyewear 3. Gown or apron
1,2
To avoid the dilution effects caused by too much sodium heparin during ABG sampling of an adult, what should you do? 1. Ensure a sample volume greater than 2 ml. 2. Use dry heparin instead. 3. Fill the needle dead space only. 4. Use saline if dry heparin is not available.
1,2,3
Which of the following are TRUE about a blood gas analyzer's waste fluids? 1. A strong disinfectant should be added to waste fluid containers. 2. Waste fluids should be handled as if they were blood samples. 3. Waste fluids should be treated as potentially infectious.
1,2,3
Components of a laboratory blood gas analyzer include which of the following? 1. three-electrode measuring chamber 2. reagent containers 3. calibrating gas tanks 4. waste container
1,2,3,4
Which of the following can help avoid the problem of arterial blood sample contamination with air? 1. Discarding frothy samples 2. Fully expelling any bubbles 3. Mixing before expelling air 4. Capping syringe quickly
1,2,4
Which of the following could you use to assess the adequacy of ventilation in an intubated child receiving mechanical ventilation? 1. Transcutaneous PCO2 2. Capnography 3. Pulse oximetry 4. Arterial blood gas
1,2,4
Continuous noninvasive assessment of patient oxygenation can be provided by which of the following methods? 1. Transcutaneous PO2 2. Capnography 3. Pulse oximetry 4. Indwelling arterial line
1,3
When analyzing a blood gas control sample, you notice that the result falls outside the 2 SD range. How could you verify that this was a random error (error of imprecision)? 1. Repeat the analysis on a different analyzer. 2. Compare the control to an actual patient sample. 3. Rerun the control sample a second time.
1,3
When inspecting an internal quality-control plot for a blood gas analyzer, you notice several data points sporadically appearing outside the 2 standard deviation (SD) range. This represents what type of analytic error? 1. random error 2. bias 3. imprecision 4. systematic error
1,3
Which of the following changes would occur if an arterial blood sample of a patient breathing room air were exposed to a large air bubble? 1. Decreased PCO2 2. Decreased pH 3. Increased PO2
1,3
While analyzing a blood gas control sample, you notice a trending of several PCO2 values above the 2 SD range over the last six control samples run. What corrective action would you consider at this time?1. Check the function of the PCO2 electrode. 2. Rerun the control sample a second time. 3. Repair or replace any failed components.
1,3
Signs and or symptoms of Methhemoglobinemia include: 1. PaO2 < 60 mmHg 2. Dark chocolate brown or rust colored blood 3. Normal PaO2 4. Saturations > 95% 5. Saturations 85% to 89% 6. slate blue skin color to cyanosis
2,3,5,6
The advantage that point-of-care testing has over traditional laboratory testing is that point-of-care testing: a. does not require trained personnel to run the tests b. is more accurate than traditional laboratory testing c. reduces turnaround time d. utilizes equipment that is less expensive
c
The procedure whereby a blood-measuring instrument is exposed to samples at two or more known levels to ensure accuracy is termed: a. Proficiency testing b. Preanalytic validation c. Analyzer calibration d. Preventive maintenance
c
What is the normal range for CaO2? a. 4 to 8 mL/dL b. 12 to 16 mL/dL c. 16 to 20 mL/dL d. 8 to 12 mL/dL
c
What is the process of testing a new blood gas analyzer to confirm a manufacturer's claims? a. automated calibration b. proficiency testing c. performance validation d. preventive maintenance
c
What media are used to calibrate a blood gas analyzer's gas electrodes? a. tonometered human blood samples b. standard pH buffer solutions c. precision mixtures of O2 and CO2 d. blood-like control media
c
When analyzing an ABG sample from a patient with acute respiratory distress syndrome and refractory hypoxemia, you notice a PaO2 of 141 mm Hg and a PaCO2 of 14 mm Hg. Which of the following analytic errors should you suspect? a. Excessive time since sample collection b. Excessive heparin in the sample c. Exposure of the blood sample to air d. Sample admixture with venous blood
c
When calibrating the day shift blood gas analyzer, a quality control that falls within _______ of the mean on the Levey-Jennings graph is considered to be in control. a. ± 6SD b. ± 3SD c. ± 2SD d. ± 4SD
c
Which of the following parameters represents the respiratory component of acid-base status? a. PaO2 b. HCO3 c. PaCO2 d. BE
c
Which of the following represents a normal (P(A-a)O2 for a 50-year old woman breathing room air? a. 45 mmHg b. 105 mmHg c. 15 mmHg d. 75 mmHg
c
The blood gas results from a patient breathing a confirmed O2 concentration of 30% indicate a PaO2 of 250 mmHg. Based on this datum, it can be concluded that the:pH 7.21, PaCO2 67 mmHg, HCO3 26 mmHg, BE +2 mmol/L, PaO2 53 mmHg, SaO2 78%Hb 10.1 g/dL, CaO2 10.4 mL/dL.Respiratory rate 25 breaths/minFiO2 0.70 a. Patient must be at high altitude b. PaO2 is in the expected range for this %O2 c. Patient has a large pulmonary shunt d. PaO2 is in error and should be remeasured
d
To ensure that the output of a blood gas analyzer is both accurate and linear across the range of measured values, a calibration procedure must measure what? a. two different parameters at the same time b. two different parameters at different times c. parameters with known input values at one point d. parameters with known input values at two points
d
To evaluate a patient's acid-base status, you would recommend which of the following? a. CO-oximetry b. Pulse oximetry c. Transcutaneous PCO2 d. Arterial blood gas
d
What is the common range for PaO2 breathing air at sea level? a. 50 to 60 mmHg b. 70 to 80 mmHg c. 60 to 70 mmHg d. 80 to 100 mmHg
d
What is the quality control procedure of analysis and reporting on externally provided control media with unknown values? :a. automated calibration b. performance validation c. preventive maintenance d. proficiency testing
d
Which of the following is the best indicator of metabolic acid-base status? a. Plasma HCO3- b. T40 HCO3- c. Standard HCO3- d. Base excess
d
Which of the following is the preferred site for arterial puncture? a. Dorsalis pedis b. Femoral artery c. Brachial artery d. Radial artery
d
Which of the following ratios of HCO3/PaCO2 would result in a pH of 7.40? a. 15:1 b. 6:0.82 c. 25:40 d. 10:0.5
d
