CAA Perioperative Care & Patient Monitoring 1 — Questions and Answers
Question 1: According to ASA basic monitoring standards, which of the following must be continuously monitored via capnography during general anesthesia with an endotracheal tube?
- End-tidal CO2 (ETCO2) (Correct answer)
- Urine output
- Central venous pressure
- Serum electrolytes
Correct answer: End-tidal CO2 (ETCO2)
ASA standards require continuous capnography (ETCO2) to confirm tracheal intubation and monitor ventilation throughout general anesthesia.
Question 2: What is the normal range for end-tidal CO2 (ETCO2) during controlled mechanical ventilation in a healthy patient?
- 10–20 mmHg
- 20–30 mmHg
- 35–45 mmHg (Correct answer)
- 50–60 mmHg
Correct answer: 35–45 mmHg
Normal ETCO2 during mechanical ventilation is 35–45 mmHg, reflecting adequate alveolar ventilation and CO2 elimination.
Question 3: A sudden decrease in ETCO2 to near zero during mechanical ventilation most likely indicates:
- Hypoventilation
- Breathing circuit disconnection or cardiac arrest (Correct answer)
- Metabolic alkalosis
- Increased CO2 production from fever
Correct answer: Breathing circuit disconnection or cardiac arrest
A sudden drop in ETCO2 to near zero indicates loss of CO2 delivery to the sensor, most commonly from circuit disconnection or sudden cessation of circulation (cardiac arrest).
Question 4: Which phase of perioperative care focuses on medical history review, physical examination, and optimization of comorbidities before the planned procedure?
- Intraoperative phase
- Postoperative phase
- Preoperative phase (Correct answer)
- Recovery room phase
Correct answer: Preoperative phase
The preoperative phase encompasses patient assessment, risk stratification, and optimization of existing medical conditions prior to surgery.
Question 5: The Bispectral Index (BIS) monitor primarily provides information about:
- Degree of neuromuscular blockade
- Depth of anesthesia via processed EEG analysis (Correct answer)
- Real-time cardiac output
- Cerebral blood flow velocity
Correct answer: Depth of anesthesia via processed EEG analysis
BIS processes EEG signals into a numerical index (0–100) to provide a quantitative measure of anesthetic depth and help reduce the risk of intraoperative awareness.
Question 6: Intraoperative awareness under anesthesia is most effectively detected and prevented by monitoring which parameter?
- Mean arterial pressure
- Heart rate variability
- BIS index or end-tidal volatile anesthetic concentration (Correct answer)
- Urine output trends
Correct answer: BIS index or end-tidal volatile anesthetic concentration
Monitoring BIS values (target 40–60) or maintaining minimum alveolar concentration (MAC) values of volatile agents ≥0.7 are the most evidence-based strategies to prevent intraoperative awareness.
Question 7: To ensure adequate renal perfusion during anesthesia, minimum acceptable urine output should be maintained at:
- 0.1 mL/kg/hr
- 0.5 mL/kg/hr (Correct answer)
- 2.0 mL/kg/hr
- 5.0 mL/kg/hr
Correct answer: 0.5 mL/kg/hr
A urine output of at least 0.5 mL/kg/hr during anesthesia indicates adequate renal perfusion and is the accepted minimum threshold for monitoring intraoperative fluid status.
CAA Perioperative Care & Patient Monitoring 1
According to ASA basic monitoring standards, which of the following must be continuously monitored via capnography during general anesthesia with an endotracheal tube?