, TABLE OF CONTENT
Chapter 1: Sleep-Related Breathing Disorder
Chapter 2: Anesthetic Considerations for Obstructive Lung Disease
Chapter 3: Restrictive Respiratory Diseases and Lung Transplantation
Chapter 4: Ischemic Heart Disease
Chapter 5: Valvular Heart Disease
Chapter 6: Congenital Heart Disease
Chapter 7: Abnormalities of Cardiac Conduction and Rhythms
Chapter 8: Systemic and Pulmonary Arterial Hypertension
Chapter 9: Heart Failure and Cardiomyopathies
Chapter 10: Pericardial Disease and Cardiac Trauma
Chapter 11: Vascular Disease
Chapter 12: Diseases Affecting the Brain
Chapter 13: Disorders of the Spine and Spinal Cord
Chapter 14: Diseases of the Autonomic and Peripheral Nervous Systems
Chapter 15: Diseases of Aging
Chapter 16: Diseases of the Liver and Biliary Tract
Chapter 17: Inborn Errors of Metabolism
Chapter 18: Nutritional Diseases: Obesity and Malnutrition
Chapter 19: Fluid, Electrolyte, and Acid-Base Disorders
Chapter 20: Renal Disease
Chapter 21: Endocrine Disease
Chapter 22: Hematologic Disorders
Chapter 23: Skin and Musculoskeletal Disorders
Chapter 24: Infectious Diseases
Chapter 25: Diseases Related to Immune System Dysfunction
Chapter 26: Cancer
Chapter 27: Psychiatric Disease, Substance Use Disorders, and Drug Overdose
Chapter 28: Anesthetic Considerations for Adults With Substance Use Disorder or Acute Intoxication
Chapter 29: Pediatric Diseases
Chapter 30: Medical Disorders in Pregnancy
Chapter 31: Chronic Pain
Chapter 32: The Critically Injured Patient
,Chapter 1: Sleep-Related Breathing Disorder
1. What pathophysiologic mechanism defines central sleep apnea?
A. Cyclic collapse of pharyngeal tissues during inspiration
B. Sustained hypoventilation from intrinsic chest wall stiffness
C. Transient cessation of central respiratory drive to muscles
D. Progressive narrowing of subglottic structures during sleep
Answer: C
Rationale: Central sleep apnea syndromes arise from a temporary withdrawal of central neural output from the
medullary respiratory centers to the ventilatory pump muscles. Airflow ceases during these episodes without
ongoing or cyclic efforts against an occluded upper airway.
Keywords: central sleep apnea, respiratory drive, apnea classification
2. When transitioning from wakefulness into non-rapid eye movement sleep, how is the ventilatory response to
arterial carbon dioxide altered?
A. It steepens the carbon dioxide ventilatory response slope
B. It shifts the carbon dioxide apneic threshold rightward
C. It abolishes peripheral carotid body chemoreceptor output completely
D. It stimulates accessory pharyngeal dilators during passive expiration
Answer: B
Rationale: The onset of non-rapid eye movement sleep removes the tonic wakefulness drive to breathe, shifting
the ventilatory response curve to arterial carbon dioxide to the right. Consequently, a higher PaCO2 level is
required to stimulate automatic ventilation, establishing a distinct apneic threshold below which central apnea
occurs.
Keywords: ventilatory control, carbon dioxide response, apneic threshold
3. Which range of the apnea-hypopnea index classifies obstructive sleep apnea as moderate severity?
A. 15 to 29 events per hour
,B. 5 to 14 events per hour
C. 30 to 45 events per hour
D. 1 to 4 events per hour
Answer: A
Rationale: Polysomnography quantifies sleep-disordered breathing severity using the apnea-hypopnea index,
defined as the average number of apneas and hypopneas per hour of recorded sleep. An index between 15 and 29.9
events per hour denotes moderate obstructive sleep apnea, whereas values from 5 to 14.9 define mild disease and
values of 30 or greater denote severe disease.
Keywords: apnea-hypopnea index, polysomnography, severity classification
4. Preoperative screening reveals loud snoring and daytime somnolence in an elective surgical candidate. How
many positive STOP-BANG items establish intermediate risk?
A. Exactly five positive items
B. At least six positive items
C. Three or four positive items
D. Exactly one positive item
Answer: C
Rationale: The STOP-BANG questionnaire stratifies the probability of obstructive sleep apnea into low risk (0 to 2
items), intermediate risk (3 to 4 items), and high risk (5 to 8 items). Patients scoring 3 or 4 points exhibit an
intermediate likelihood of disease and warrant structured perioperative airway precautions.
Keywords: STOP-BANG questionnaire, preoperative screening, risk stratification
5. Under general anesthesia, a patient develops complete pharyngeal airway collapse despite active diaphragmatic
excursions. Loss of motor output to which dilator muscle is primarily responsible?
A. The genioglossus muscle
B. The cricothyroid muscle
C. The sternohyoid muscle
D. The thyroarytenoid muscle
Answer: A
Rationale: The genioglossus is the primary upper airway dilator muscle responsible for maintaining pharyngeal
patency against subatmospheric intraluminal inspiratory pressures. Neural output to the hypoglossal nerve and
genioglossus decreases markedly during sleep, particularly during rapid eye movement stages, leading to airway
collapse in anatomically vulnerable individuals.
,Keywords: genioglossus, pharyngeal collapsibility, rapid eye movement sleep
6. Daytime arterial blood gas analysis in an obese patient demonstrates a PaCO2 of 48 mm Hg without intrinsic
lung disease. Which diagnostic entity does this represent?
A. Primary central sleep apnea
B. Sleep-related hypoxemia disorder
C. Idiopathic nocturnal laryngospasm
D. Sleep-related hypoventilation disorder
Answer: D
Rationale: Sleep-related hypoventilation disorders, exemplified by obesity hypoventilation syndrome, are
characterized by an elevated daytime PaCO2 greater than 45 mm Hg that worsens significantly during sleep. This
condition is distinct from isolated obstructive sleep apnea, reflecting chronic blunting of central ventilatory drive
and decreased chest wall compliance.
Keywords: sleep-related hypoventilation, obesity hypoventilation syndrome, hypercapnia
7. How is sleep-related hypoxemia disorder clinically distinguished from sleep-related hypoventilation?
A. Presence of sustained nocturnal hypercapnia
B. Absence of nocturnal carbon dioxide retention
C. Demonstration of cyclic upper airway collapse
D. Occurrence of periodic Cheyne-Stokes breathing
Answer: B
Rationale: Sleep-related hypoxemia disorder is characterized by prolonged periods of arterial oxygen
desaturation during sleep without concurrent hypercapnia. It typically reflects underlying ventilation-perfusion
mismatching or pulmonary vascular disease rather than primary hypoventilation.
Keywords: sleep-related hypoxemia, hypoventilation, differential diagnosis
8. Severe obstructive sleep apnea with an apnea-hypopnea index of 42 events per hour generates nocturnal surges
that promote which long-term cardiovascular consequence?
A. Systemic arterial hypertension
B. Aortic valve calcification
C. Constrictive pericarditis
D. Subclavian steal syndrome
,Answer: A
Rationale: Recurrent upper airway obstruction triggers intermittent hypoxemia, hypercapnia, and dramatic
negative intrathoracic pressure swings that repeatedly stimulate the sympathetic nervous system. These cyclic
adrenergic surges cause sustained systemic vasoconstriction, leading to neurohumoral remodeling and treatment-
resistant systemic hypertension.
Keywords: obstructive sleep apnea, systemic hypertension, sympathetic activation
9. Which sleep-related phenomenon represents an isolated symptom or normal variant rather than a formal
disease entity?
A. Obesity hypoventilation syndrome
B. Congenital central hypoventilation
C. Cheyne-Stokes breathing syndrome
D. Nocturnal catathrenia groaning
Answer: D
Rationale: The international classification of sleep disorders categorizes isolated symptoms and normal variants
as benign phenomena that do not cause significant daytime impairment or hypoxemia. Catathrenia, which consists
of nocturnal groaning during prolonged expiration, represents an isolated acoustic parasomnia rather than an
obstructive respiratory syndrome.
Keywords: catathrenia, normal variants, sleep classification
10. Measuring the pharyngeal critical closing pressure in an anesthetized individual yields which finding when
high mechanical collapsibility exists?
A. Significantly negative pressure values
B. Values well below atmospheric pressure
C. Pressures under minus ten centimeters
D. Positive intraluminal pressure values
Answer: D
Rationale: Pharyngeal critical closing pressure (Pcrit) defines the intraluminal pressure at which the upper airway
collapses. Individuals with normal airways have negative Pcrit values (below minus 5 cm H2O), meaning collapse
occurs only under negative inspiratory suction, whereas positive Pcrit values indicate a collapsible airway prone to
spontaneous closure even at baseline.
Keywords: critical closing pressure, pharyngeal collapsibility, airway mechanics
,11. What threshold score on the full STOP-BANG screening questionnaire indicates high risk for obstructive sleep
apnea?
A. Five or more positive points
B. Two or fewer positive points
C. Three to four positive points
D. Exactly eight positive points
Answer: A
Rationale: A score of 5 or more positive responses on the 8-item STOP-BANG questionnaire categorizes a surgical
patient as high risk for moderate-to-severe obstructive sleep apnea. Alternatively, high risk is established with a
score of 2 or more on the STOP items combined with specific high-risk physical characteristics.
Keywords: STOP-BANG, high risk threshold, airway screening
12. Prior to urgent cholecystectomy, a patient exhibits features strongly suggestive of undiagnosed obstructive
sleep apnea. In the absence of polysomnography, which strategy is recommended?
A. Treat the patient as high risk for airway collapse
B. Cancel the urgent procedure until polysomnography is done
C. Administer prophylactic high-dose oral benzodiazepines preoperatively
D. Avoid supplemental oxygen administration during post-anesthesia recovery
Answer: A
Rationale: When a patient with clinical features strongly suggestive of obstructive sleep apnea requires urgent
surgery without time for formal polysomnography, professional society guidelines recommend presumptively
treating the patient as high risk. This involves employing opioid-sparing analgesia, regional techniques when
feasible, and extended postoperative monitoring.
Keywords: undiagnosed sleep apnea, preoperative screening, management guidelines
13. Planning intraoperative care for a patient with severe obstructive sleep apnea requires which analgesic
approach to meet safety guidelines?
A. Sole reliance on high-dose remifentanil infusion
B. Intermittent boluses of unmonitored intravenous morphine
C. Multimodal opioid-sparing analgesia with regional blocks
D. Intraoperative long-acting sedating neuroleptic infusions
Answer: C
Rationale: The American Society of Anesthesiologists practice guidelines for obstructive sleep apnea emphasize
, minimizing systemic opioids due to their respiratory depressant and sedative effects. A multimodal opioid-sparing
strategy incorporating local or regional nerve blocks, non-opioid analgesics, and alpha-2 agonists minimizes the
risk of postoperative airway obstruction.
Keywords: opioid-sparing analgesia, multimodal analgesia, anesthetic technique
14. Why do clinical guidelines favor regional anesthesia over general anesthesia in patients with obstructive sleep
apnea?
A. Regional anesthesia prevents postoperative surgical wound infections
B. Regional anesthesia avoids changes in systemic arterial blood pressure
C. Regional anesthesia completely eliminates the need for any monitoring
D. Regional anesthesia reduces upper airway depressant drug requirements
Answer: D
Rationale: Regional anesthesia techniques, including neuraxial blocks and peripheral nerve blocks, minimize or
avoid the administration of general anesthetics, neuromuscular blockers, and systemic opioids. By reducing
systemic central nervous system depression, regional anesthesia preserves baseline upper airway muscle tone and
protective reflexes during the vulnerable perioperative period.
Keywords: regional anesthesia, airway patency, anesthetic technique
15. Following general anesthesia in a patient with severe sleep apnea, which patient position is optimal for tracheal
extubation?
A. Prone position with neck flexion
B. Steep Trendelenburg supine position
C. Strictly flat supine position
D. Semi-upright or lateral position
Answer: D
Rationale: Extubating patients with obstructive sleep apnea in a semi-upright (sitting or reverse Trendelenburg)
or lateral decubitus position decreases posterior tongue displacement and reduces pharyngeal collapsibility.
Furthermore, the semi-upright posture increases functional residual capacity and improves oxygenation compared
to the supine position.
Keywords: extubation criteria, patient positioning, airway management
16. Postoperative patient-controlled hydromorphone is prescribed for an individual with moderate obstructive
Chapter 1: Sleep-Related Breathing Disorder
Chapter 2: Anesthetic Considerations for Obstructive Lung Disease
Chapter 3: Restrictive Respiratory Diseases and Lung Transplantation
Chapter 4: Ischemic Heart Disease
Chapter 5: Valvular Heart Disease
Chapter 6: Congenital Heart Disease
Chapter 7: Abnormalities of Cardiac Conduction and Rhythms
Chapter 8: Systemic and Pulmonary Arterial Hypertension
Chapter 9: Heart Failure and Cardiomyopathies
Chapter 10: Pericardial Disease and Cardiac Trauma
Chapter 11: Vascular Disease
Chapter 12: Diseases Affecting the Brain
Chapter 13: Disorders of the Spine and Spinal Cord
Chapter 14: Diseases of the Autonomic and Peripheral Nervous Systems
Chapter 15: Diseases of Aging
Chapter 16: Diseases of the Liver and Biliary Tract
Chapter 17: Inborn Errors of Metabolism
Chapter 18: Nutritional Diseases: Obesity and Malnutrition
Chapter 19: Fluid, Electrolyte, and Acid-Base Disorders
Chapter 20: Renal Disease
Chapter 21: Endocrine Disease
Chapter 22: Hematologic Disorders
Chapter 23: Skin and Musculoskeletal Disorders
Chapter 24: Infectious Diseases
Chapter 25: Diseases Related to Immune System Dysfunction
Chapter 26: Cancer
Chapter 27: Psychiatric Disease, Substance Use Disorders, and Drug Overdose
Chapter 28: Anesthetic Considerations for Adults With Substance Use Disorder or Acute Intoxication
Chapter 29: Pediatric Diseases
Chapter 30: Medical Disorders in Pregnancy
Chapter 31: Chronic Pain
Chapter 32: The Critically Injured Patient
,Chapter 1: Sleep-Related Breathing Disorder
1. What pathophysiologic mechanism defines central sleep apnea?
A. Cyclic collapse of pharyngeal tissues during inspiration
B. Sustained hypoventilation from intrinsic chest wall stiffness
C. Transient cessation of central respiratory drive to muscles
D. Progressive narrowing of subglottic structures during sleep
Answer: C
Rationale: Central sleep apnea syndromes arise from a temporary withdrawal of central neural output from the
medullary respiratory centers to the ventilatory pump muscles. Airflow ceases during these episodes without
ongoing or cyclic efforts against an occluded upper airway.
Keywords: central sleep apnea, respiratory drive, apnea classification
2. When transitioning from wakefulness into non-rapid eye movement sleep, how is the ventilatory response to
arterial carbon dioxide altered?
A. It steepens the carbon dioxide ventilatory response slope
B. It shifts the carbon dioxide apneic threshold rightward
C. It abolishes peripheral carotid body chemoreceptor output completely
D. It stimulates accessory pharyngeal dilators during passive expiration
Answer: B
Rationale: The onset of non-rapid eye movement sleep removes the tonic wakefulness drive to breathe, shifting
the ventilatory response curve to arterial carbon dioxide to the right. Consequently, a higher PaCO2 level is
required to stimulate automatic ventilation, establishing a distinct apneic threshold below which central apnea
occurs.
Keywords: ventilatory control, carbon dioxide response, apneic threshold
3. Which range of the apnea-hypopnea index classifies obstructive sleep apnea as moderate severity?
A. 15 to 29 events per hour
,B. 5 to 14 events per hour
C. 30 to 45 events per hour
D. 1 to 4 events per hour
Answer: A
Rationale: Polysomnography quantifies sleep-disordered breathing severity using the apnea-hypopnea index,
defined as the average number of apneas and hypopneas per hour of recorded sleep. An index between 15 and 29.9
events per hour denotes moderate obstructive sleep apnea, whereas values from 5 to 14.9 define mild disease and
values of 30 or greater denote severe disease.
Keywords: apnea-hypopnea index, polysomnography, severity classification
4. Preoperative screening reveals loud snoring and daytime somnolence in an elective surgical candidate. How
many positive STOP-BANG items establish intermediate risk?
A. Exactly five positive items
B. At least six positive items
C. Three or four positive items
D. Exactly one positive item
Answer: C
Rationale: The STOP-BANG questionnaire stratifies the probability of obstructive sleep apnea into low risk (0 to 2
items), intermediate risk (3 to 4 items), and high risk (5 to 8 items). Patients scoring 3 or 4 points exhibit an
intermediate likelihood of disease and warrant structured perioperative airway precautions.
Keywords: STOP-BANG questionnaire, preoperative screening, risk stratification
5. Under general anesthesia, a patient develops complete pharyngeal airway collapse despite active diaphragmatic
excursions. Loss of motor output to which dilator muscle is primarily responsible?
A. The genioglossus muscle
B. The cricothyroid muscle
C. The sternohyoid muscle
D. The thyroarytenoid muscle
Answer: A
Rationale: The genioglossus is the primary upper airway dilator muscle responsible for maintaining pharyngeal
patency against subatmospheric intraluminal inspiratory pressures. Neural output to the hypoglossal nerve and
genioglossus decreases markedly during sleep, particularly during rapid eye movement stages, leading to airway
collapse in anatomically vulnerable individuals.
,Keywords: genioglossus, pharyngeal collapsibility, rapid eye movement sleep
6. Daytime arterial blood gas analysis in an obese patient demonstrates a PaCO2 of 48 mm Hg without intrinsic
lung disease. Which diagnostic entity does this represent?
A. Primary central sleep apnea
B. Sleep-related hypoxemia disorder
C. Idiopathic nocturnal laryngospasm
D. Sleep-related hypoventilation disorder
Answer: D
Rationale: Sleep-related hypoventilation disorders, exemplified by obesity hypoventilation syndrome, are
characterized by an elevated daytime PaCO2 greater than 45 mm Hg that worsens significantly during sleep. This
condition is distinct from isolated obstructive sleep apnea, reflecting chronic blunting of central ventilatory drive
and decreased chest wall compliance.
Keywords: sleep-related hypoventilation, obesity hypoventilation syndrome, hypercapnia
7. How is sleep-related hypoxemia disorder clinically distinguished from sleep-related hypoventilation?
A. Presence of sustained nocturnal hypercapnia
B. Absence of nocturnal carbon dioxide retention
C. Demonstration of cyclic upper airway collapse
D. Occurrence of periodic Cheyne-Stokes breathing
Answer: B
Rationale: Sleep-related hypoxemia disorder is characterized by prolonged periods of arterial oxygen
desaturation during sleep without concurrent hypercapnia. It typically reflects underlying ventilation-perfusion
mismatching or pulmonary vascular disease rather than primary hypoventilation.
Keywords: sleep-related hypoxemia, hypoventilation, differential diagnosis
8. Severe obstructive sleep apnea with an apnea-hypopnea index of 42 events per hour generates nocturnal surges
that promote which long-term cardiovascular consequence?
A. Systemic arterial hypertension
B. Aortic valve calcification
C. Constrictive pericarditis
D. Subclavian steal syndrome
,Answer: A
Rationale: Recurrent upper airway obstruction triggers intermittent hypoxemia, hypercapnia, and dramatic
negative intrathoracic pressure swings that repeatedly stimulate the sympathetic nervous system. These cyclic
adrenergic surges cause sustained systemic vasoconstriction, leading to neurohumoral remodeling and treatment-
resistant systemic hypertension.
Keywords: obstructive sleep apnea, systemic hypertension, sympathetic activation
9. Which sleep-related phenomenon represents an isolated symptom or normal variant rather than a formal
disease entity?
A. Obesity hypoventilation syndrome
B. Congenital central hypoventilation
C. Cheyne-Stokes breathing syndrome
D. Nocturnal catathrenia groaning
Answer: D
Rationale: The international classification of sleep disorders categorizes isolated symptoms and normal variants
as benign phenomena that do not cause significant daytime impairment or hypoxemia. Catathrenia, which consists
of nocturnal groaning during prolonged expiration, represents an isolated acoustic parasomnia rather than an
obstructive respiratory syndrome.
Keywords: catathrenia, normal variants, sleep classification
10. Measuring the pharyngeal critical closing pressure in an anesthetized individual yields which finding when
high mechanical collapsibility exists?
A. Significantly negative pressure values
B. Values well below atmospheric pressure
C. Pressures under minus ten centimeters
D. Positive intraluminal pressure values
Answer: D
Rationale: Pharyngeal critical closing pressure (Pcrit) defines the intraluminal pressure at which the upper airway
collapses. Individuals with normal airways have negative Pcrit values (below minus 5 cm H2O), meaning collapse
occurs only under negative inspiratory suction, whereas positive Pcrit values indicate a collapsible airway prone to
spontaneous closure even at baseline.
Keywords: critical closing pressure, pharyngeal collapsibility, airway mechanics
,11. What threshold score on the full STOP-BANG screening questionnaire indicates high risk for obstructive sleep
apnea?
A. Five or more positive points
B. Two or fewer positive points
C. Three to four positive points
D. Exactly eight positive points
Answer: A
Rationale: A score of 5 or more positive responses on the 8-item STOP-BANG questionnaire categorizes a surgical
patient as high risk for moderate-to-severe obstructive sleep apnea. Alternatively, high risk is established with a
score of 2 or more on the STOP items combined with specific high-risk physical characteristics.
Keywords: STOP-BANG, high risk threshold, airway screening
12. Prior to urgent cholecystectomy, a patient exhibits features strongly suggestive of undiagnosed obstructive
sleep apnea. In the absence of polysomnography, which strategy is recommended?
A. Treat the patient as high risk for airway collapse
B. Cancel the urgent procedure until polysomnography is done
C. Administer prophylactic high-dose oral benzodiazepines preoperatively
D. Avoid supplemental oxygen administration during post-anesthesia recovery
Answer: A
Rationale: When a patient with clinical features strongly suggestive of obstructive sleep apnea requires urgent
surgery without time for formal polysomnography, professional society guidelines recommend presumptively
treating the patient as high risk. This involves employing opioid-sparing analgesia, regional techniques when
feasible, and extended postoperative monitoring.
Keywords: undiagnosed sleep apnea, preoperative screening, management guidelines
13. Planning intraoperative care for a patient with severe obstructive sleep apnea requires which analgesic
approach to meet safety guidelines?
A. Sole reliance on high-dose remifentanil infusion
B. Intermittent boluses of unmonitored intravenous morphine
C. Multimodal opioid-sparing analgesia with regional blocks
D. Intraoperative long-acting sedating neuroleptic infusions
Answer: C
Rationale: The American Society of Anesthesiologists practice guidelines for obstructive sleep apnea emphasize
, minimizing systemic opioids due to their respiratory depressant and sedative effects. A multimodal opioid-sparing
strategy incorporating local or regional nerve blocks, non-opioid analgesics, and alpha-2 agonists minimizes the
risk of postoperative airway obstruction.
Keywords: opioid-sparing analgesia, multimodal analgesia, anesthetic technique
14. Why do clinical guidelines favor regional anesthesia over general anesthesia in patients with obstructive sleep
apnea?
A. Regional anesthesia prevents postoperative surgical wound infections
B. Regional anesthesia avoids changes in systemic arterial blood pressure
C. Regional anesthesia completely eliminates the need for any monitoring
D. Regional anesthesia reduces upper airway depressant drug requirements
Answer: D
Rationale: Regional anesthesia techniques, including neuraxial blocks and peripheral nerve blocks, minimize or
avoid the administration of general anesthetics, neuromuscular blockers, and systemic opioids. By reducing
systemic central nervous system depression, regional anesthesia preserves baseline upper airway muscle tone and
protective reflexes during the vulnerable perioperative period.
Keywords: regional anesthesia, airway patency, anesthetic technique
15. Following general anesthesia in a patient with severe sleep apnea, which patient position is optimal for tracheal
extubation?
A. Prone position with neck flexion
B. Steep Trendelenburg supine position
C. Strictly flat supine position
D. Semi-upright or lateral position
Answer: D
Rationale: Extubating patients with obstructive sleep apnea in a semi-upright (sitting or reverse Trendelenburg)
or lateral decubitus position decreases posterior tongue displacement and reduces pharyngeal collapsibility.
Furthermore, the semi-upright posture increases functional residual capacity and improves oxygenation compared
to the supine position.
Keywords: extubation criteria, patient positioning, airway management
16. Postoperative patient-controlled hydromorphone is prescribed for an individual with moderate obstructive
