Question Answer
Which blood gas analyzer electrode uses a separate reference electrode? B) pH
Before performing puncture or cannulation of the radial artery, what should you do? B) Perform the Allen test to ensure collateral circulation
The advantage that point-of-care testing has over traditional laboratory testing is that point-of-care testing: A) reduces turnaround time.
What is the measurement of CO2 in respiratory gases called? B) Capnometry
What is the normal gradient between PaCO2 and PETCO2? A) 1 to 5 mm Hg
You return to a patient’s room 20 minutes after drawing an ABG. Which of the following should you check at this time? I. Puncture site for hematoma II. Adequacy of distal circulation A) I and II
All of the following are common sites for transcutaneous blood gas electrode placement except the. D) Thigh
All of the following sites are used for arterial blood sampling by percutaneous needle puncture except: D) Carotid
A mechanically ventilated patient exhibits a sudden decrease in end-tidal CO2 levels. All of the following are possible causes of this change except. C) Increase in CO2 production
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? C) Cross-check the sample with an SpO2 reading.
Pulse oximeter readings are generally unreliable at saturations below what level? A) 80%
If patient pain or anxiety occurs during arterial puncture, which of the following will probably occur? B) Hyperventilation
Capillary puncture should NOT be performed at or through what location? I. Inflamed or edematous tissue II. Localized areas of infection III. The fingers of neonates IV. Previous puncture sites D) I, II, III, and IV
What is the most common technique used to measure CO2 in respiratory gases? A) Infrared absorption
Patient parameters that should be assessed as part of arterial blood sampling include all of the following except. A) Blood pressure
To measure PCO2, blood gas analyzers use what electrode? A) Severinghaus
Before connecting the sample syringe to an adult’s arterial line stopcock, what would you do? B) Aspirate at least 5 ml of fluid or blood using a waste syringe.
During a single-breath capnogram, the sharp downstroke and return to baseline that normally occurs after the end-tidal point indicates what? B) Inspiration of fresh respiratory gas.
Before attaching a transcutaneous blood gas monitor sensor to a patient, what should you do? I. Provide a specified warm-up time and set the probe temperature. II. Check the membrane and prepare a sensor with an adhesive ring and gel. III. Prepare the monitoring site (remove excess hair and clean the skin).D) I, II, and III
What is the normal range for end-tidal CO2 as measured by capnography? B) 5% to 6%
Tissue injuries to be on guard for at the site of transcutaneous blood gas electrode placement include all of the following except which one? B) Hematomas
A blood gas analyzer measures all of the following except. A) HCO3-
Which of the following is false about invasive versus noninvasive monitoring? B) Laboratory analysis of gas exchange is usually noninvasive in nature.
A patient being monitored by capnography exhibits a sudden rise in end-tidal CO2 levels. All of the following are possible causes of this change except. B) Massive pulmonary embolism
. To avoid transmission of blood-borne diseases when handling a used needle, what should you do? I. Never recap the needle without a safety device (or scoop method). II. Never handle the needle with both hands. III. Never remove the need the syringe by hand. IV. Always dispose in a proper sharps container.D) I, II, III, and IV
During a single-breath capnogram, what does the occurrence of a plateau indicate? D) Exhalation of mainly alveolar gas.
The equipment necessary for capillary blood sampling includes all of the following except. C) 1-ml syringe
How does the Clark polarographic O2 electrode function? C) Uses O2 to produce a reduction–oxidation reaction.
You are asked to provide continuous monitoring of the FIO2 provided by a humidified O2 delivery system using a galvanic cell analyzer. Where would you install the analyzer’s sensor? A) Proximal to the heated humidifier.
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)? I. Repeat the analysis on a different analyzer. II. Compare the control to an actual patient sample. B) I and III
What is a normal level for CaO2? C) 18 to 20 ml/100 ml
Through which pulmonary artery catheter port would you obtain a mixed venous blood sample? C) Distal (catheter tip) port
When conducting ABG analysis in the laboratory, obvious signs of preanalytical error include all of the following except: D) unmixed sample.
An outpatient scheduled for an arterial blood sample enters the pulmonary lab 20 minutes late and out of breath, having run up four flights of stairs. What should you do? C) Wait 5 minutes before taking the sample.
Before a sample of capillary blood is taken, what should you do to the site? I. Warmed to 42° C for 10 minutes III. Cleaned with an antiseptic solution B) I and III
In which of the following patients would transcutaneous blood gas monitoring most likely provide inaccurate or erroneous results? D) Patient in hypovolemic shock.
How often should blood gas calibration verification by control media take place? C) At least two levels of control media should be analyzed every 8 hours
What media are used to calibrate a blood gas analyzer’s gas electrodes? C) Precision mixtures of O2 and CO2
All of the following are grounds for finding an alternative site for arterial puncture except: C) anticoagulation therapy.
How is the accuracy of a blood gas analyzer determined? B) Comparing the analyzer’s measurements to known values.
To avoid thermal injury with transcutaneous blood gas monitor sensors, what should you do? I. Carefully monitor the sensor temperature. III. Regularly rotate the sensor site. B) I and III
An alert outpatient awaiting bronchoscopy has an SpO2 reading of 81% breathing room air. The patient appears in no distress and exhibits no signs of hypoxemia. Which of the following would be the best initial action to take in this situation? A) Switch sites or replace the sensor probe.
What is the best site for capillary puncture in an infant? A) Lateral aspect of the heel’s plantar surface
Precautions and/or possible complications of arterial puncture include which of the following? I. Arteriospasm II. Embolization III. Infection IV. Hemorrhage D) I, II, III, and IV
Statistically derived limits for internal quality control of blood gas samples are usually set at what appropriate level? B) 2 standard deviations from the mean
Which of the following are TRUE about a blood gas analyzer’s waste fluids? I. A strong disinfectant should be added to waste fluid containers. II. Waste fluids should be handled as if they were blood samples. III. Waste fluids should be treated as potentially infectious.D) I, II, and III
Indications for arterial blood sampling by percutaneous needle puncture include all of the following except the need to: B) assess the adequacy of tissue oxygenation.
Indications for pulse oximetry include all of the following except the need: B) for measurements of abnormal Hb.
A mixed venous blood sample obtained from a pulmonary artery catheter sample has a PO2 of 85 mm Hg and a hemoglobin saturation of 95%. Which of the following is likely? I. The pulmonary artery catheter balloon was not deflated. III. The blood sample was withdrawn too quickly.B) I and III
What is the most common source of error and false alarms with pulse oximetry? B) Patient motion artifact