CABT Medical Equipment Operations Questions and Answers

Question 1

A patient connected to a mechanical ventilator triggers a persistent 'High Pressure' alarm. The patient is not coughing, and the tubing is free of kinks and water. What is the MOST likely operational issue or patient condition causing this alarm?

Accepted Answer

An increase in airway resistance due to bronchospasm or a mucus plug.

Answer

A high-pressure alarm indicates that the ventilator requires more pressure than the preset limit to deliver the set tidal volume. This is typically caused by an obstruction or increased resistance in the airway. Bronchospasm (constriction of the airways) or a mucus plug physically narrows the passage, increasing resistance. A disconnection or cuff leak would cause a 'Low Pressure' alarm. Apnea would trigger a specific 'Apnea' or 'Low Respiratory Rate' alarm.

Question 2

When comparing biphasic and monophasic defibrillators, which of the following is a key operational advantage of biphasic technology?

Accepted Answer

They require significantly less energy to achieve the same or higher efficacy, reducing potential cardiac damage.

Answer

Biphasic defibrillators send the current in two directions, which allows them to terminate arrhythmias with significantly lower energy levels (e.g., 120-200J) compared to monophasic devices (which may go up to 360J). This lower energy reduces the risk of skin burns and damage to the heart muscle. Biphasic technology is the current standard and has largely replaced the older monophasic technology.

Question 3

A technician is preparing an autoclave for a standard sterilization cycle for wrapped surgical instruments. Which combination of temperature, pressure, and time is a widely recognized minimum for effective steam sterilization in a gravity displacement sterilizer?

Accepted Answer

121°C (250°F) at 15 psi for 30 minutes

Answer

The standard and widely accepted parameters for steam sterilization of wrapped goods in a gravity displacement autoclave are 121°C (250°F) at a pressure of at least 15 psi for a minimum of 30 minutes. These specific conditions of steam, temperature, pressure, and time are required to effectively kill all microorganisms, including spores. The other options represent incorrect combinations of these critical parameters.

Question 4

A pulse oximeter provides an SpO2 reading by measuring the differential absorption of two wavelengths of light. Which operational principle allows the device to distinguish between arterial and venous blood?

Accepted Answer

The device only analyzes the pulsatile component of the light absorption, which corresponds to arterial blood flow.

Answer

A pulse oximeter identifies arterial blood by detecting the pulsatile nature of its flow, which corresponds to the heartbeat. The device measures the light absorption during both the systolic (pulse) and diastolic (no pulse) phases. The changing, or AC component, of the signal is attributed to the pulsatile arterial blood, while the constant, or DC component, is from non-pulsatile venous blood and tissue. By focusing only on the AC component, it can accurately calculate arterial oxygen saturation (SpO2).

Question 5

During a surgical procedure using a monopolar electrosurgical unit (ESU), the active electrode delivers the cutting current. What is the essential function of the large patient return electrode (dispersive pad)?

Accepted Answer

To provide a low-resistance path for the electrical current to safely exit the body and return to the generator.

Answer

In monopolar electrosurgery, the electrical circuit flows from the ESU generator, through the active electrode, into the patient's tissue, and then must return to the generator. The patient return electrode has a large surface area to safely disperse the current as it exits the body, preventing burns at the exit site. Without this complete and safe path, the current could seek alternative routes and cause significant injury.

(CABT) Certified Associate in Biomedical Technology Practice Test

(CABT) Certified Associate in Biomedical Technology Practice Test

CABT Medical Equipment Operations Questions and Answers