CAA Anesthesia Equipment & Technology Flashcards

Which BIS (bispectral index) value range is typically targeted for adequate general anesthesia?

Answer: 40–60

A BIS value of 40–60 indicates adequate anesthetic depth for general anesthesia, while values above 70 suggest lighter sedation and below 40 suggest excessively deep anesthesia.

What is the primary hazard of a hypoxic gas mixture that an oxygen analyzer in the breathing circuit is designed to detect?

Answer: Delivery of less than 21% inspired oxygen

An in-circuit oxygen analyzer detects when inspired oxygen fraction falls below 21% (hypoxic mixture), providing an alarm before patient harm occurs.

A sudden decrease in end-tidal CO2 to near zero with continued ventilator cycling most likely indicates:

Answer: Massive pulmonary embolism or esophageal intubation

A sudden drop in ETCO2 to near zero suggests either esophageal intubation (no alveolar CO2 being sampled) or a catastrophic drop in pulmonary blood flow such as massive PE or cardiac arrest.

In a closed scavenging interface, the positive-pressure relief valve opens when:

Answer: Suction flow is insufficient to handle the waste gas volume

The positive-pressure relief valve on a closed scavenging interface vents waste gas to atmosphere if suction flow cannot keep pace with the volume of gas being released.

Which ventilator alarm should prompt immediate assessment for a circuit disconnect or massive leak?

Answer: Low exhaled tidal volume / disconnect alarm

A low exhaled tidal volume or disconnect alarm indicates that ventilated gas is not returning through the circuit, suggesting a disconnection or major leak.

Which monitoring modality uses near-infrared spectroscopy (NIRS) to assess regional cerebral oxygen saturation?

Answer: Cerebral oximetry (rSO2)

Cerebral oximetry (rSO2) uses NIRS sensors placed on the forehead to non-invasively estimate regional cerebral oxygen saturation and detect cerebral ischemia.