BCA Monitoring Equipment & Technology 2 — Questions and Answers
Question 1: Which component of a capnograph waveform corresponds to alveolar plateau?
- Phase I
- Phase II
- Phase III (Correct answer)
- Phase IV
Correct answer: Phase III
Phase III of the capnograph waveform represents the alveolar plateau, where exhaled CO2 reaches its maximum concentration.
Question 2: What does a sudden decrease in end-tidal CO2 to near zero most likely indicate?
- Hypoventilation
- Esophageal intubation (Correct answer)
- Malignant hyperthermia
- Increased metabolic rate
Correct answer: Esophageal intubation
A sudden drop of ETCO2 to near zero strongly suggests esophageal intubation, as the esophagus produces no CO2.
Question 3: The anesthesia machine's oxygen flush valve delivers oxygen at approximately what flow rate?
- 2-4 L/min
- 6-8 L/min
- 35-75 L/min (Correct answer)
- 100-150 L/min
Correct answer: 35-75 L/min
The oxygen flush valve delivers a high flow of 35-75 L/min to rapidly fill the breathing circuit with oxygen.
Question 4: Which alarm condition is indicated by a sustained loss of airway pressure in a mechanically ventilated patient?
- Bronchospasm
- Circuit disconnection (Correct answer)
- Endobronchial intubation
- Tension pneumothorax
Correct answer: Circuit disconnection
A sustained loss of airway pressure in a mechanically ventilated patient most commonly indicates circuit disconnection.
Question 5: In a pulse oximeter, which wavelengths of light are used to differentiate oxyhemoglobin from deoxyhemoglobin?
- 450 nm and 550 nm
- 660 nm and 940 nm (Correct answer)
- 700 nm and 800 nm
- 550 nm and 660 nm
Correct answer: 660 nm and 940 nm
Pulse oximeters use red light (660 nm) and infrared light (940 nm) because oxyhemoglobin and deoxyhemoglobin absorb these wavelengths differently.
Question 6: What is the primary cause of falsely low SpO2 readings with pulse oximetry in patients with severe peripheral vasoconstriction?
- Elevated carboxyhemoglobin
- Reduced pulsatile blood flow (Correct answer)
- Venous pulsation artifact
- High ambient light interference
Correct answer: Reduced pulsatile blood flow
Severe vasoconstriction reduces pulsatile blood flow at the probe site, making it difficult for the oximeter to detect the signal accurately.
Question 7: Which monitoring modality best detects early myocardial ischemia during anesthesia?
- Lead II ECG
- Lead V5 ECG (Correct answer)
- Central venous pressure
- Arterial blood pressure
Correct answer: Lead V5 ECG
Lead V5 is the single best lead for detecting left ventricular ischemia, covering the territory of the left anterior descending artery.
BCA Monitoring Equipment & Technology 2
Which component of a capnograph waveform corresponds to alveolar plateau?