CABT Medical Equipment Operations 4 — Questions and Answers
Question 1: What does the term 'tidal volume' specifically refer to in mechanical ventilation?
- Total lung capacity at maximum inhalation
- The volume of air moved in one normal breath cycle (Correct answer)
- The residual volume remaining after full exhalation
- The pressure required to overcome airway resistance
Correct answer: The volume of air moved in one normal breath cycle
Tidal volume is the volume of air inhaled or exhaled during a single normal breath, typically set between 6–8 mL/kg of ideal body weight in ventilated patients.
Question 2: Which safety feature in an infusion pump prevents free-flow of medication when the door is opened?
- Anti-siphon valve
- Free-flow protection clamp (Correct answer)
- Upstream detector
- Air-in-line sensor
Correct answer: Free-flow protection clamp
Free-flow protection clamps automatically occlude the tubing when the pump door is opened, preventing gravity-driven free flow of potentially dangerous medications.
Question 3: In an automated external defibrillator (AED), what does the device analyze before advising a shock?
- Blood pressure waveform
- Heart rhythm via ECG electrodes (Correct answer)
- Oxygen saturation level
- Respiratory rate
Correct answer: Heart rhythm via ECG electrodes
AEDs use built-in algorithms to analyze the patient's ECG rhythm through electrode pads to determine whether a shockable rhythm such as VF or pulseless VT is present.
Question 4: What is the purpose of 'PEEP' in mechanical ventilation?
- To increase inspiratory flow rate
- To maintain positive pressure in the airway at end-expiration and prevent alveolar collapse (Correct answer)
- To trigger a breath when the patient makes an inspiratory effort
- To limit the maximum airway pressure during inspiration
Correct answer: To maintain positive pressure in the airway at end-expiration and prevent alveolar collapse
Positive End-Expiratory Pressure (PEEP) keeps a baseline positive pressure in the airways at the end of exhalation, preventing alveolar collapse and improving oxygenation.
Question 5: A biomedical technician performs an electrical safety test and measures chassis leakage current of 600 µA on a Class I device. What action should be taken?
- Place the device back in service; it is within normal limits
- Remove the device from service; it exceeds the 500 µA limit for Class I devices (Correct answer)
- Recalibrate the leakage current tester and retest
- Escalate to manufacturer for optional firmware update
Correct answer: Remove the device from service; it exceeds the 500 µA limit for Class I devices
AAMI/IEC standards for Class I medical devices set a maximum chassis leakage current of 500 µA under normal conditions; 600 µA exceeds this limit and requires the device be removed from service.
Question 6: Which type of medical gas outlet uses a pin-index safety system to prevent misconnection?
- DISS (Diameter Index Safety System) outlets
- Quick-connect wall outlets
- Cylinder valve connections for small cylinders (Correct answer)
- Pipeline bulk supply connections
Correct answer: Cylinder valve connections for small cylinders
The Pin Index Safety System (PISS) uses unique pin configurations on small medical gas cylinders to ensure only the correct gas regulator can be attached.
Question 7: What is 'compressive stockings pump' (sequential compression device) used for in clinical settings?
- Delivering positive pressure ventilation to COPD patients
- Preventing deep vein thrombosis by promoting venous return in lower extremities (Correct answer)
- Measuring compartment pressure in trauma patients
- Providing cardiac assist during low-output states
Correct answer: Preventing deep vein thrombosis by promoting venous return in lower extremities
Sequential compression devices inflate and deflate chambers around the legs in a sequential pattern to mimic muscle pumping action and prevent DVT in immobile patients.
CABT Medical Equipment Operations 4
What does the term 'tidal volume' specifically refer to in mechanical ventilation?