Sleep Medicine Practice Questions

Q: A 42-year-old obese male presented with disturbed sleep and daytime somnolence. All of the following are correct except?

Pharyngeal muscle contraction increases OSA. ***Pharyngeal muscle contraction increases OSA*** - Obstructive sleep apnea (OSA) is caused by the collapse of the upper airway due to the **relaxation** and consequent loss of tone in the **pharyngeal muscles** during sleep, not by their contraction [1]. - While muscle contraction normally helps maintain airway patency, **reduced muscle activity** allows the airway to narrow or collapse. *Apnea with hypoxia* - **Apnea**, defined as a cessation of breathing for at least 10 seconds, often leads to periods of **hypoxia** (decreased blood oxygen levels) due to insufficient gas exchange [1]. - This **recurrent hypoxia** is a hallmark of OSA and contributes to its cardiovascular and neurological consequences. *Apnea with awakening* - Following an apneic episode, the body's protective reflex often causes a brief **arousal or awakening** from sleep to restore airway patency and ventilation [2]. - These frequent **micro-awakenings** are a primary reason for the disturbed sleep and subsequent daytime somnolence experienced by patients with OSA [2]. *Apnea with fall in saturation* - During an apneic event, the lack of airflow into the lungs results in a **decrease in oxygen saturation (SpO2)**, which is a key diagnostic criterion for OSA severity [2]. - This **desaturation** is directly linked to the duration and frequency of apneic episodes.

Q: Which of the following statements about obstructive sleep apnea is false?

Contraction of pharyngeal muscles can worsen obstruction. ***Contraction of pharyngeal muscles can worsen obstruction*** - In **obstructive sleep apnea (OSA)**, the pharyngeal muscles are normally responsible for maintaining airway patency [1]. - A *contraction* of these muscles would *open* the airway, whereas *relaxation* or *loss of tone* leads to collapse and obstruction. *Apnea is associated with high respiratory effort* - During an **apneic episode** in OSA, the airway is *obstructed*, leading to continued but **unsuccessful inspiratory efforts** against a closed airway. - This results in a significant increase in **respiratory effort** as the diaphragm and accessory muscles try to overcome the obstruction. *Apnea is associated with fall in SpO2* - The cessation of airflow during **apnea** prevents **gas exchange**, leading to a progressive decrease in **oxygen saturation (SpO2)**. - This **hypoxia** is a hallmark physiological consequence of apneic events and often triggers arousal from sleep [2]. *Apnea is associated with sudden awakening* - The combination of **hypoxia** and **hypercapnia** (increased CO2), along with the increased respiratory effort, stimulates the central nervous system [2]. - This stimulation causes a **brief arousal or awakening** from sleep, often accompanied by gasping or snorting, to re-establish airway patency.

Q: A patient presents with snoring and excessive daytime sleepiness. What is the initial investigation of choice?

Polysomnography. ***Polysomnography*** - This is the **gold standard** for diagnosing **sleep apnea**, which is characterized by snoring and excessive daytime sleepiness. - It records multiple physiological parameters during sleep, including **brain activity, oxygen levels, heart rate, and breathing patterns**. *Laryngoscopy* - This procedure examines the larynx and vocal cords; it is commonly used for evaluating **hoarseness or throat pain**, not primary sleep disorders. - While it can identify structural abnormalities in the upper airway, it doesn't assess the **physiological impact** of these abnormalities during sleep. *MRI of the neck* - This imaging technique provides detailed anatomical views of soft tissues in the neck, which can identify **structural airway obstruction** in specific cases. - However, it does not assess the dynamic physiological changes occurring during sleep that lead to conditions like **obstructive sleep apnea**. *Echocardiography* - This test is used to evaluate the **heart's structure and function**, primarily for cardiac issues like heart failure or valvular disease. - While sleep apnea can have cardiovascular consequences, **echocardiography** is not an initial diagnostic tool for the sleep disorder itself.

Q: What AHI range indicates MILD obstructive sleep apnea?

5 - 15. **5 - 15** - An **Apnea-Hypopnea Index (AHI)** between **5 and 15** events per hour signifies **mild obstructive sleep apnea (OSA)** [1]. - This classification helps guide treatment decisions, as mild OSA may respond to lifestyle modifications or oral appliances [1]. *<5* - An AHI of **less than 5** events per hour is generally considered **normal** or indicative of no significant sleep apnea [1]. - While some individuals may have mild symptoms with an AHI below 5, it typically does not meet the diagnostic criteria for OSA [1]. *15 - 30* - An AHI in this range indicates **moderate obstructive sleep apnea**. - Patients with moderate OSA often experience more pronounced symptoms and typically require intervention such as **Continuous Positive Airway Pressure (CPAP)** therapy. *>30* - An AHI **greater than 30** events per hour is classified as **severe obstructive sleep apnea**. - This level of severity is associated with significant health risks and almost always necessitates immediate and effective treatment like **CPAP**.

Q: The Apnea-Hypopnea Index (AHI) is specifically used for diagnosing and assessing the severity of which condition?

Obstructive sleep apnea (OSA). ***Obstructive sleep apnea (OSA)*** - The **Apnea-Hypopnea Index (AHI)** quantifies the average number of apneas and hypopneas per hour of sleep, which is the primary metric for diagnosing and determining the severity of OSA [1]. - An apnea is a complete cessation of airflow, while a hypopnea is a significant reduction in airflow, both leading to **oxygen desaturation** and sleep disruption [1]. *Emphysema* - Emphysema is a form of **Chronic Obstructive Pulmonary Disease (COPD)** characterized by destruction of the alveoli, leading to reduced gas exchange. - Its diagnosis and severity assessment rely on **spirometry** (e.g., FEV1/FVC ratio) and imaging, not AHI [2]. *Asthma* - Asthma is a chronic inflammatory airway disease characterized by **reversible airway obstruction** and bronchial hyperresponsiveness [2]. - Its diagnosis involves **pulmonary function tests** like spirometry, often with bronchodilator challenge, and clinical symptoms, but not AHI [2]. *Hyaline membrane disease* - **Hyaline membrane disease** (also known as Infant Respiratory Distress Syndrome) is a respiratory disorder primarily affecting premature infants due to insufficient surfactant production. - Diagnosis is based on **clinical presentation** at birth, chest X-rays, and arterial blood gas analysis, not AHI.

Q: What is the minimum duration of apnea defined in obstructive sleep apnea?

>=10 sec. ***>=10 sec*** - An **apnea event** in obstructive sleep apnea (OSA) is defined as a cessation of airflow for at least **10 seconds** [1] during sleep. - This duration is crucial for distinguishing between normal respiratory pauses and clinically significant apneas. *5 sec* - A 5-second period of no airflow is generally considered a **normal physiological variation** or a brief pause, not meeting the criteria for apnea in OSA. - Such brief pauses typically do not lead to significant **oxygen desaturation** [1] or arousal from sleep. *15 sec* - While 15 seconds would certainly qualify as an apnea event, the **minimum threshold** for definition is 10 seconds [1]. - Longer durations of apnea are indicative of more **severe airflow obstruction**, but the 10-second mark is the standard lower limit. *20 sec* - Similarly, 20 seconds represents a **prolonged apnea event**, but it is not the **minimum duration** for diagnosis. - Apneas lasting 20 seconds or more are associated with greater **physiological stress** and more noticeable clinical symptoms.

Q: Which of the following statements about obstructive sleep apnea is true?

Prone to hypertension. ***Prone to hypertension*** - Obstructive sleep apnea (OSA) is strongly associated with **hypertension** due to recurrent episodes of hypoxemia, hypercapnia, and increased sympathetic activity. - The repeated arousals and stress responses during sleep cause a persistent elevation in blood pressure. [1] *Nocturnal asphyxia* - While OSA involves episodes of **apnea** and **hypopnea** (reduced breathing), the term **asphyxia** implies complete cessation of breathing leading to severe oxygen deprivation and CO2 retention, which is generally not the typical presentation of OSA as patients usually eventually gasp for air. [1] - OSA is characterized by partial or complete **upper airway obstruction** during sleep, leading to reduced airflow and oxygen desaturation, but not usually full asphyxia. [1] *Alcoholism is a cofactor* - **Alcohol consumption**, particularly before bedtime, acts as an **exacerbating factor** for OSA by causing muscle relaxation in the upper airway, but it is not typically considered a primary cofactor in the development of the condition itself. - While alcohol can worsen OSA symptoms and severity, it is not a direct underlying cause in the way obesity or anatomical abnormalities are. *Overnight oximetry alone is sufficient for diagnosing obstructive sleep apnea.* - **Overnight oximetry** can detect oxygen desaturations but is **not sufficient** for a definitive diagnosis of OSA, as it does not measure airflow, respiratory effort, or sleep stages. - A definitive diagnosis requires a **polysomnography (PSG)**, which records multiple physiological parameters including airflow, respiratory effort, oxygen saturation, heart rate, and brain activity.

Q: Patient with obstructive sleep apnea-hypopnea syndrome is unlikely to have which of the following?

Bradycardia during sleep episodes. ***Bradycardia during sleep episodes*** - While patients with **obstructive sleep apnea (OSA)** commonly experience various cardiovascular complications, **bradycardia** during apneic episodes is *less typical* than **tachycardia**. - The body's initial response to apnea and **hypoxia** usually involves a sympathetic surge leading to tachycardia upon arousal, followed by bradycardia if the apnea is prolonged. However, the dominant pattern is often elevated heart rate variability. *Normal oxygen saturation throughout sleep* - Patients with OSA frequently experience intermittent **hypoxemia** due to repeated apneas and hypopneas, leading to significant drops in **oxygen saturation** [1]. - A *normal oxygen saturation throughout sleep* would effectively rule out significant OSA, as desaturation is a hallmark of the condition [1]. *Absence of snoring* - **Snoring** is a classic and highly prevalent symptom of OSA, caused by the vibration of upper airway tissues as air struggles to pass through an obstructed pharynx. - While not all snorers have OSA, the *absence of snoring* makes OSA less likely, although it can occur in some subsets of patients, particularly those with central sleep apnea or certain anatomical variations. *Decreased neck circumference* - A **large neck circumference** is a well-established anatomical risk factor for OSA, indicating increased soft tissue in the neck that can contribute to upper airway collapse. - A *decreased neck circumference* would generally be protective against OSA, making it less likely for an individual to have the condition.

Q: All of the following criteria are required for diagnosis of obesity hypoventilation syndrome except -

Hypertension. ***Hypertension*** - While **hypertension** is a common comorbidity in patients with **obesity hypoventilation syndrome (OHS)**, it is _not_ a diagnostic criterion. - OHS is defined by specific respiratory and obesity-related parameters, not the presence of associated cardiovascular conditions. *BMI $\geq$ 30 kg/m$^2$* - A **body mass index (BMI)** of **30 kg/m$^2$** or greater is a fundamental criterion for diagnosing OHS, as the syndrome is directly linked to obesity. - Severe obesity leads to mechanical compression of the lungs and chest wall, contributing to hypoventilation. *PaCO$_{2}$ > 45 mmHg* - A **daytime arterial partial pressure of carbon dioxide (PaCO$_{2}$)** greater than **45 mmHg** is a key diagnostic criterion, indicating chronic alveolar hypoventilation. - This persistent hypercapnia is present even when other causes like obstructive lung disease have been excluded. *Sleep-disordered breathing* - **Sleep-disordered breathing**, most commonly **obstructive sleep apnea (OSA)**, is almost universally present in OHS patients and is a required diagnostic criterion [1]. - The combination of severe obesity and OSA often leads to the development of chronic hypoventilation [1].

Question 1

A 42-year-old obese male presented with disturbed sleep and daytime somnolence. All of the following are correct except?

Accepted Answer

Pharyngeal muscle contraction increases OSA

Answer

Apnea with hypoxia

Answer

Apnea with awakening

Answer

Apnea with fall in saturation

Question 2

Which of the following statements about obstructive sleep apnea is false?

Accepted Answer

Contraction of pharyngeal muscles can worsen obstruction

Answer

Apnea is associated with high respiratory effort

Answer

Apnea is associated with fall in SpO2

Answer

Apnea is associated with sudden awakening

Question 3

A patient presents with snoring and excessive daytime sleepiness. What is the initial investigation of choice?

Accepted Answer

Polysomnography

Answer

Laryngoscopy

Answer

MRI of the neck

Answer

Echocardiography

Question 4

What AHI range indicates MILD obstructive sleep apnea?

Accepted Answer

5 - 15

Answer

15 - 30

Answer

>30

Answer

<5

Question 5

The Apnea-Hypopnea Index (AHI) is specifically used for diagnosing and assessing the severity of which condition?

Accepted Answer

Obstructive sleep apnea (OSA)

Answer

Emphysema

Answer

Asthma

Answer

Hyaline membrane disease

Question 6

What is the minimum duration of apnea defined in obstructive sleep apnea?

Accepted Answer

>=10 sec

Answer

20 sec

Answer

15 sec

Answer

5 sec

Question 7

Which of the following statements about obstructive sleep apnea is true?

Accepted Answer

Prone to hypertension

Answer

Nocturnal asphyxia

Answer

Alcoholism is a cofactor

Answer

Overnight oximetry alone is sufficient for diagnosing obstructive sleep apnea.

Question 8

A 56-year-old woman with diabetes, hypertension, and hyperlipidemia is found to have an A1C of 11 despite her best attempts at diet and faithfully taking her metformin and glyburide. She reports severe fatigue and sleepiness in the daytime, which has limited her ability to exercise. On examination, she is obese, has a full appearing posterior pharynx, clear lungs, a normal heart examination, and trace bilateral edema. Her TSH is 2.0 m/L (normal). Before adding another oral agent or switching to insulin, what is the best next step?

Accepted Answer

Arrange for a sleep study to check the patient for obstructive sleep apnea.

Answer

Consider prescribing a sleep aid to help her sleep better and increase her energy to exercise during the day.

Answer

Assess for possible depression as a contributor to her fatigue.

Answer

Educate the patient on sleep hygiene as a supportive measure to improve her overall well-being.

Question 9

Patient with obstructive sleep apnea-hypopnea syndrome is unlikely to have which of the following?

Accepted Answer

Bradycardia during sleep episodes

Answer

Absence of snoring

Answer

Normal oxygen saturation throughout sleep

Answer

Decreased neck circumference

Question 10

All of the following criteria are required for diagnosis of obesity hypoventilation syndrome except -

Accepted Answer

Hypertension

Answer

PaCO2 > 45 mmHg

Answer

BMI 30 kg/m2

Answer

Sleep disorder breathing

Sleep Medicine — MCQs

Sleep Medicine — MCQs

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