OSA Flashcards
OSA: General
- Increased resistance to airflow; No breathing when trying to breathe
- Results in hypopnea or Apnea
– Degree and duration->Hypoxia, anoxia, hypercarbia - Arouses CNS-> Lighter Sleep Stage (nREM 1 or 2)
- causes: partial awake, Relieve obstruction, resume breathing
- Fragmented Sleep: Depending on arousal frequency
Apnea
- Complete Obstruction
- cesstion or near-complete cessation (>70%) of oronasal airflow
- at least 10 seconds
Hypopnea
- Partial Obstruction
- 30% decrease oronasal airflow= 4% decrease Oxyhemoglobin saturation
- 50% decrease oronasal airflow= 3% decrease oxyhemoglobin saturation
Types of Apnea Pattern
- Obstructed Sleep Apnea
- Central Sleep Apnea
- Mixed Sleep Apnea
Obstructed Sleep Apnea
- Absence of airflow w/persistent ventilatory efforts
Central Sleep Apnea
- Absence of airflow w/no ventilatory efforts
Mixed Sleep Apnea
- Both Central and Obstructive events
- Central then Obstructive
Etiology of OSA
- Structural risk factors
- Non-structural risk factors
OSA: Structural Risk Factors
Nasal Cavity/Nasopharynx
1. Septal Deviation
2. Turbinate Hypertrophy
3. Nasal Polyps
4. Adenoid Hypertrophy
Oral Cavity/ Oropharynx
1. Soft palate and Uvula elongation
2. Tonsillar Hypertrophy
3. Macroglossia
4. Retrognathia
5. Rugae of posterior pharyngeal wall
Hypopharynx/Larynx
1. Omega Shaped Epiglottis
2. Laryngeal-tracheal stenosis
OSA: Non-structural Risk Factors
- Obesity
- Age
- Sex
- Post-menopause
- Family Hx
- Genetics
- Alcohol
- Smoking
OSA: Obesity
- Major risk factor
- Increased adipocity around pharynx and body
- Potential Candidates: Sleep in supine position w/:
increased neck circumferance (collar size >16-17) or
High BMI(>25)
OSA: Age
- Increased fat in parapharyngeal area
- Structural change around pharynx
- Soft palate lengthens
OSA: Sex
- Men have increased fat around pharyngeal airway
OSA: Post-menopause
- Post menopause=higher prevalence
- Post-menopause w/hormone replacement therapy= same as Pre-menopause
- Pre-menopause=Protected even with other risk factors
OSA: Family Hx & Genetics
*Familial suceptibilty increases directly with number of affected relatives
* 1st degree relatives: 1.5-2x
* APOE= younger w/OSA
* Carniofacial Disorders: Pierre-Robine Syndrome
have micrognathia, glossoptossis, cleft palate, tonge prolapse backwards
OSA: Alcohol
- Relaxes upper airway dilator muscles
- increases upper airway resistance
- Prolong apnea duration
- suppress arousals
- increased obstructive episodes frequency
- Increased hypoxia severity
OSA: Smoking
- Inflammation and damage to upper airway
- structural and functional changes
- increased risk of collapse during sleep
- greater risk of moderate to severe OSA vs non-smokers
Diseases associated with OSA
- Hypertension (35%)
- Atrial Fibrillation
- Pacemakers
- Diabetes
- Congestive Heart Failure
- Obesity
- Drug resistant hypertension
- Night Time Heart Attacks (91%)
OSA: Nighttime Symptoms
- Loud persistent snoring
- witnessed pauses in breathing (apneas)
- Choking or gasping for air
- restless sleep
- frequent bathroom visits
OSA: Daytime Symptoms
- Early Morning Headaches
- EDS (Excessive Daytime Sleepiness)
- Poor Concentration
- Irritabilty
- Falling asleep during routine activities
How are women who have OSA different from men
More likely to have:
* insomnia
* depression
* thyroid disease
* nightmares
* palpitations
* hallucinations
* Restless leg syndrome
Less likely to have:
* Snoring
* witnessed apneas
OSA: Car crashes
- Untreated=higher collision rate
AHI> 15= 8.1x risk of MVA
AHI>34= 15x risk of MVA - Treated w/CPAP=same as control
Excessive Daytime Sleepiness (EDS)
- Most common symptom
- Reduces quality of life
- impaired daytime performance
- neurocognitive deficits (Memory)
- Feel sleepy during activities that require being alert (driving)
- Epworth Sleepiness Scale (ESS)= subjective assessment
- Multiple Sleep Latency Test (MSLT)=objectively measures
Epworth Sleepiness Scale: Interpretation
- 0-7=abnormal sleepiness unlikely
- 8-9= avg daytime sleepiness
- 10-15: might be excessively sleepy depeing on situation. Might Seek medical attention
- 16-24: Excessively sleepy. Should seek medical attention
What are methods to dx OSA?
- Polysomnography (PSG)
Polysomnography (PSG)
Overnight sleep study
Monitor and Record Multiple physiologic parameters:
* EEG-brain waves
* EOG-eye movements
* EMG-jaw musce actiivty and leg movements
* ECG-heart rate and rhythm
* Pulse Ox-blood oxygen saturation
* Nasal Thermistor-nasal airflow and CO2 levels
* Chest and Abdominal Strain gauses-breathing efforts
Classifcation of OSA
