CBET Ultimate 4 — Questions and Answers
Question 1: A centrifugal blood pump used in ECMO loses prime and shows air in the circuit. What is the IMMEDIATE corrective action?
- Increase pump RPM
- Clamp the circuit and notify the perfusionist/physician immediately (Correct answer)
- Add normal saline to the reservoir
- Decrease gas sweep flow
Correct answer: Clamp the circuit and notify the perfusionist/physician immediately
Air in an ECMO circuit is a life-threatening emergency requiring immediate circuit clamping and clinical team notification to prevent air embolism.
Question 2: What does the term 'macroshock' mean in the context of electrical safety?
- Current delivered directly to the heart via a catheter
- Sufficient current applied to the body surface to cause ventricular fibrillation (typically >100 mA) (Correct answer)
- Any shock that causes skin burns
- Shock from voltages above 1,000 V
Correct answer: Sufficient current applied to the body surface to cause ventricular fibrillation (typically >100 mA)
Macroshock refers to externally applied current large enough to cause physiological harm including ventricular fibrillation, typically requiring >100 mA.
Question 3: A digital X-ray flat panel detector shows persistent ghost images (image lag). What is the MOST likely cause?
- Incorrect collimation
- Residual charge trapped in amorphous silicon photodiodes between exposures (Correct answer)
- Overexposed cassette
- Faulty anti-scatter grid
Correct answer: Residual charge trapped in amorphous silicon photodiodes between exposures
Image lag in flat panel detectors occurs when residual charge from a prior exposure is incompletely cleared from the photodiode array before the next acquisition.
Question 4: Which type of medical gas pipeline color is used for oxygen in US healthcare facilities per NFPA 99?
- Blue
- Green (Correct answer)
- Yellow
- Gray
Correct answer: Green
In the United States, oxygen medical gas pipelines and outlets are color-coded green per NFPA 99 standards.
Question 5: A patient-controlled analgesia (PCA) pump is delivering more drug than programmed. Which safety mechanism has MOST likely failed?
- The anti-siphon valve or free-flow protection mechanism (Correct answer)
- The display backlight
- The alarm speaker
- The battery backup system
Correct answer: The anti-siphon valve or free-flow protection mechanism
Free-flow protection and anti-siphon valves prevent gravity-driven uncontrolled drug delivery; failure of these mechanisms causes over-infusion.
Question 6: In a clinical laboratory analyzer, a hemolyzed sample would cause which type of result error?
- Falsely decreased potassium levels
- Falsely elevated potassium and LDH due to intracellular contents released (Correct answer)
- Falsely decreased bilirubin
- Falsely elevated sodium
Correct answer: Falsely elevated potassium and LDH due to intracellular contents released
Hemolysis releases intracellular contents including potassium and LDH into the plasma, causing falsely elevated measurements of these analytes.
Question 7: When performing acceptance testing on a new infusion pump, which document provides the minimum performance requirements to verify?
- The hospital formulary
- The manufacturer's operator manual and device specifications (Correct answer)
- OSHA 1910 standards
- The hospital's billing codes
Correct answer: The manufacturer's operator manual and device specifications
Acceptance testing verifies that the device meets manufacturer specifications documented in the operator manual, confirming it arrived undamaged and functional.
CBET Ultimate 4
A centrifugal blood pump used in ECMO loses prime and shows air in the circuit.
What is the IMMEDIATE corrective action?