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, Stoelting's Anesthesia and Co-Existing Disease, 9th Edition — 960-Question Exam Bank
Section 1: Respiratory & Sleep-Related Disorders
Chapter 1: Sleep Related Breathing Disorders (Questions 1–30)
1. A patient with obstructive sleep apnea (OSA) has an apnea-hypopnea index (AHI) of 42
events/hour. How is this classified?
A) Normal
B) Mild
C) Moderate
D) Severe
Answer: D
Rationale: ** AHI 5–14.9 = mild; 15–29.9 = moderate; ≥30 = severe. An AHI of 42 is severe OSA.
Anesthesia Pearl:** AHI alone does not capture perioperative risk. Consider hypoxemic burden, comorbidity,
opioid requirement, and PAP adherence.
Exam Strategy:** Remember the anchors: 5, 15, 30.
---
2. During polysomnography, a patient has repetitive episodes of absent airflow with continued
inspiratory effort. What is the mechanism?
A) Loss of central respiratory drive
B) Upper airway collapse despite ongoing respiratory effort
C) Fixed tracheal stenosis
D) Pulmonary diffusion impairment
Answer: B
Rationale: ** Obstructive sleep apnea is characterized by upper airway narrowing/collapse during sleep
with persistent respiratory effort. Reduced pharyngeal dilator muscle tone allows a susceptible airway to
collapse.
Exam Strategy:** Airflow absent + effort present = obstructive apnea.
---
3. A patient with untreated severe OSA is undergoing total knee arthroplasty. Which postoperative
analgesic strategy most reduces respiratory risk?
4
,3
, Stoelting's Anesthesia and Co-Existing Disease, 9th Edition — 960-Question Exam Bank
Section 1: Respiratory & Sleep-Related Disorders
Chapter 1: Sleep Related Breathing Disorders (Questions 1–30)
1. A patient with obstructive sleep apnea (OSA) has an apnea-hypopnea index (AHI) of 42
events/hour. How is this classified?
A) Normal
B) Mild
C) Moderate
D) Severe
Answer: D
Rationale: ** AHI 5–14.9 = mild; 15–29.9 = moderate; ≥30 = severe. An AHI of 42 is severe OSA.
Anesthesia Pearl:** AHI alone does not capture perioperative risk. Consider hypoxemic burden, comorbidity,
opioid requirement, and PAP adherence.
Exam Strategy:** Remember the anchors: 5, 15, 30.
---
2. During polysomnography, a patient has repetitive episodes of absent airflow with continued
inspiratory effort. What is the mechanism?
A) Loss of central respiratory drive
B) Upper airway collapse despite ongoing respiratory effort
C) Fixed tracheal stenosis
D) Pulmonary diffusion impairment
Answer: B
Rationale: ** Obstructive sleep apnea is characterized by upper airway narrowing/collapse during sleep
with persistent respiratory effort. Reduced pharyngeal dilator muscle tone allows a susceptible airway to
collapse.
Exam Strategy:** Airflow absent + effort present = obstructive apnea.
---
3. A patient with untreated severe OSA is undergoing total knee arthroplasty. Which postoperative
analgesic strategy most reduces respiratory risk?
4
