BCIA Breathing & Capnometry Biofeedback 2 — Questions and Answers
Question 1: In capnometry biofeedback, which metric serves as the primary real-time feedback signal?
- Heart rate variability amplitude
- Skin conductance level
- End-tidal CO2 concentration (Correct answer)
- Electromyography amplitude
Correct answer: End-tidal CO2 concentration
Capnometry biofeedback uses the CO2 concentration at the end of exhalation (EtCO2) as the primary feedback signal to guide the patient toward optimal breathing patterns.
Question 2: What breathing dysfunction is most commonly addressed with capnometry biofeedback?
- Obstructive sleep apnea
- Chronic hyperventilation disorder (Correct answer)
- Bradypnea (abnormally slow breathing)
- Cheyne-Stokes respiration
Correct answer: Chronic hyperventilation disorder
Capnometry biofeedback is most frequently used to identify and treat chronic hyperventilation disorder, training patients to maintain normal EtCO2 levels.
Question 3: Slow paced breathing at resonance frequency primarily improves which physiological parameter?
- Blood glucose regulation
- Heart rate variability (HRV) (Correct answer)
- Galvanic skin response amplitude
- Core body temperature
Correct answer: Heart rate variability (HRV)
Breathing at resonance frequency (~6 breaths/min) creates baroreflex-mediated oscillations in heart rate that maximize HRV, reflecting improved autonomic balance.
Question 4: An EtCO2 reading below what threshold is generally considered indicative of hyperventilation?
- 50 mmHg
- 45 mmHg
- 35 mmHg (Correct answer)
- 25 mmHg
Correct answer: 35 mmHg
EtCO2 below 35 mmHg falls outside the normal 35–45 mmHg range and is generally considered indicative of hypocapnia or hyperventilation.
Question 5: How does slow diaphragmatic breathing correct blood pH in a person who has been chronically hyperventilating?
- It decreases pH further into acidosis
- It has no measurable effect on blood pH
- It increases pH into greater alkalosis
- It normalizes elevated pH caused by respiratory alkalosis (Correct answer)
Correct answer: It normalizes elevated pH caused by respiratory alkalosis
Chronic hyperventilation causes respiratory alkalosis (elevated pH); slow breathing allows CO2 to rise toward normal, correcting the alkalosis and normalizing pH.
Question 6: What type of sensor is used to measure end-tidal CO2 in a capnometry biofeedback session?
- Thermistor attached to the fingertip
- Infrared CO2 analyzer placed at the nose or mouth (Correct answer)
- Surface electrodes attached to the chest wall
- Pulse oximeter clipped to the fingertip
Correct answer: Infrared CO2 analyzer placed at the nose or mouth
Capnometry uses infrared spectroscopy sensors positioned near the nostrils or mouth to detect CO2 concentration in exhaled breath in real time.
Question 7: Respiratory sinus arrhythmia (RSA) is best described as:
- An abnormal cardiac arrhythmia triggered by airway obstruction
- The natural increase in heart rate during inhalation and decrease during exhalation (Correct answer)
- Irregular breathing patterns associated with cardiovascular disease
- Synchronization of respiration with an external cardiac pacemaker
Correct answer: The natural increase in heart rate during inhalation and decrease during exhalation
RSA is the normal phenomenon where heart rate increases slightly during inhalation and decreases during exhalation, reflecting vagal modulation of cardiac rate coupled to the breathing cycle.
BCIA Breathing & Capnometry Biofeedback 2
In capnometry biofeedback, which metric serves as the primary real-time feedback signal?