OSA Flashcards
What is Obstructive Sleep Apnea (OSA)?
OSA is a disorder characterized by recurrent obstruction of the upper airway during sleep, causing hypoxia and fragmented sleep. It can be a partial or complete collapse of the airway.
What is the difference between apnea and hypopnea?
Apnea is the cessation of breathing, while hypopnea is a decrement in airflow of 50% or more associated with a 4% fall in oxygen saturation or EEG arousal.
What is the Apnea-Hypopnea Index (AHI)?
The AHI is the number of apneas or hypopneas per hour of sleep. It is a laboratory finding used to assess the severity of sleep-disordered breathing.
What is the Respiratory Effort Related Event (RERA)?
RERA is a sequence of breaths characterized by increasing effort leading to an arousal from sleep that does not meet the criteria for apnea or hypopnea.
What is the gold standard diagnostic test for Obstructive Sleep Apnea (OSA)?
Polysomnography (PSG) is the gold standard diagnostic test for OSA.
What is the definition of OSA diagnosis according to the criteria?
Diagnosis requires nocturnal breathing disturbances (snoring, snorting, gasping) or daytime sleepiness/fatigue, along with an AHI of 5 or more episodes per hour of sleep documented during a sleep study.
What are the key symptoms of OSA?
Key symptoms include snoring, excessive daytime sleepiness, difficulty staying awake, and poor sleep quality despite adequate sleep duration.
How does the anatomy of the upper airway contribute to OSA?
In OSA, there is a reduction in neuromuscular output to pharyngeal muscles, leading to airway collapse, snoring, and sleep disruption during sleep.
What is the pathophysiology of OSA?
OSA pathophysiology involves a reduction in neuromuscular output, leading to collapse of the upper airway during sleep, causing intermittent apnea or hypopnea episodes.
How does sleep position affect OSA severity?
OSA is often more severe in the supine position due to gravitational forces on the airway.
What is the Modified Mallampati Classification used for?
The Modified Mallampati Classification is used to assess the ease of oral intubation based on the visibility of the soft palate, uvula, and other oral structures.
What are the different types of sleep?
The two main types of sleep are Slow-Wave Sleep (Non-REM sleep) and REM (Rapid Eye Movement) sleep.
What is Slow-Wave Sleep?
Slow-Wave Sleep, also known as non-REM sleep, is deep, restful sleep that typically occurs in the first hour of sleep.
What are the characteristics of REM sleep?
REM sleep is characterized by active dreaming, irregular heart rate and respiration, and greatly reduced muscle tone.
What is the role of the pharyngeal muscles in OSA?
The pharyngeal muscles maintain airway patency during wakefulness. In OSA, their reduced neuromuscular output leads to airway collapse during sleep.
What is the significance of BMI in diagnosing OSA?
A BMI of 40kg/m2 or higher is classified as Type III obesity, which is a significant risk factor for OSA.
How does sleep fragmentation affect OSA patients?
Sleep fragmentation due to OSA can result in excessive daytime sleepiness and reduced cognitive performance.
What are common physical examination findings in OSA patients?
Obesity, hypertension, large neck circumference, macroglossia, and signs of heart failure are common physical findings in OSA patients.
What is the role of sympathetic surge in OSA?
In OSA, sympathetic surge occurs due to hypoxemia, leading to tachycardia and increased blood pressure.
What are common coexisting symptoms with OSA?
Common coexisting symptoms include dry mouth, nocturnal heartburn, diaphoresis, and morning headaches.
Why is a sleep study necessary for diagnosing OSA?
A sleep study, such as PSG, is necessary to confirm the diagnosis of OSA by measuring the AHI and other parameters during sleep.
STOP-Bang Questionnaire
More specific for OSA, more encompassing on the risk factors, and more objective in looking for risk factors in patients who might have OSA.
0-2 = low risk
3 or 4 =. intermediate risk
>/=5 = high risk
Gold standard for diagnosis of OSA, can be done as overnight or split-night study.
Polysomnography (PSG)
Overnight PSG vs Split-night PSG
Overnight PSG involves 8 hours of observation and intervention, while split-night PSG involves 4 hours of observation followed by 4 hours of intervention.
