CABT Clinical Procedures & Techniques 4 — Questions and Answers
Question 1: A technician sets up an infusion pump for a pediatric patient. The pump alarms 'occlusion' immediately after starting. Which is the FIRST troubleshooting step?
- Replace the pump entirely
- Check tubing for kinks, closed clamps, or positional blockages (Correct answer)
- Increase the pump's occlusion pressure threshold
- Switch to gravity infusion immediately
Correct answer: Check tubing for kinks, closed clamps, or positional blockages
Physical obstructions (kinks, clamps, needle position) are the most common cause of occlusion alarms and must be ruled out before any other intervention.
Question 2: In pulse oximetry, the 'perfusion index' (PI) displayed on some monitors indicates:
- The ratio of SpO2 to heart rate
- The strength of the pulsatile signal relative to the non-pulsatile signal (Correct answer)
- The percentage of hemoglobin saturated with oxygen
- The patient's peripheral vascular resistance
Correct answer: The strength of the pulsatile signal relative to the non-pulsatile signal
Perfusion index is the ratio of the pulsatile (AC) to non-pulsatile (DC) component of the light signal, reflecting the strength of peripheral perfusion at the sensor site.
Question 3: Which standard governs the electrical safety testing intervals and methods for medical electrical equipment in US healthcare facilities?
- NFPA 70E
- ANSI/AAMI ES60601-1
- OSHA 1910.147
- IEC 62353 (Correct answer)
Correct answer: IEC 62353
IEC 62353 'Medical electrical equipment — Recurrent test and test after repair' specifically addresses in-service safety testing protocols and intervals.
Question 4: When calibrating a tonometer (used for intraocular pressure measurement), the reference weight used for calibration represents what physical principle?
- Electrical impedance of the cornea
- Force required to flatten a defined area of the cornea (Correct answer)
- Acoustic reflection from the vitreous humor
- Light refraction index of the tear film
Correct answer: Force required to flatten a defined area of the cornea
Applanation tonometry measures the force required to flatten a 3.06 mm diameter area of the cornea, and calibration weights simulate known IOP values.
Question 5: A surgical team reports that the monopolar electrosurgery unit (ESU) causes interference with an implanted cardiac pacemaker. The SAFEST recommendation is to:
- Increase ESU power to reduce activation time
- Use bipolar electrosurgery and keep ESU current path away from the pacemaker (Correct answer)
- Place the dispersive pad as close to the ESU active electrode as possible
- Disable pacemaker sensing mode during surgery
Correct answer: Use bipolar electrosurgery and keep ESU current path away from the pacemaker
Bipolar electrosurgery confines current to a small local area, greatly reducing electromagnetic interference with implanted devices compared to monopolar current paths.
Question 6: During a neonatal incubator performance check, the technician measures temperature uniformity. The maximum allowable temperature variation within the incubator workspace per IEC 60601-2-19 is:
- ±0.5°C
- ±1.0°C (Correct answer)
- ±1.5°C
- ±2.0°C
Correct answer: ±1.0°C
IEC 60601-2-19 specifies that the temperature within the neonatal incubator workspace must not vary by more than ±1.0°C from the set temperature at any point.
Question 7: In high-level disinfection (HLD) of reusable semicritical devices, the minimum effective glutaraldehyde concentration for achieving HLD at room temperature is typically:
- 0.5%
- 1.0%
- 2.0% (Correct answer)
- 3.5%
Correct answer: 2.0%
A minimum concentration of 2.0% glutaraldehyde is required for high-level disinfection; concentrations below this threshold may not reliably inactivate mycobacteria and other resistant organisms.
CABT Clinical Procedures & Techniques 4
A technician sets up an infusion pump for a pediatric patient.
The pump alarms 'occlusion' immediately after starting.
Which is the FIRST troubleshooting step?