Sleep Apnea Flashcards
What brain wave patters accompany different stages of sleep and wakefulness
BATS Drink Blood Beta waves= awake alpha waves= falling asleep Theta waves= stage 1 Sleep spindles= stage 2 Delta waves 20% of the time, slow waves= stage 3 Delta waves >50% of the time= stave 4 REM sleep
How much time normally passes before the first REM cycle
45-60 min
By the time you wake up after a full night of sleep what percentage of sleep is REM
20-25%
How does the the time between NREM and REM sleep change over the course of a night
REM inc in length while NREM shortens
What is the normal combined time to cycle through NREM and REM sleep
90-110 min
Physiologic changes to breathing during sleep and their effects
Decreased cortical input= no higher brain stim to drive sleep
Decreased chemoreceptor sensitivity= CO2 inc and O2 dec
Decreased activation of respiratory motor neurons= breathing is less deep
Reduced alveolar ventilation with V/Q mismatches b/c of body postiion, CO, inc airway resistance, and dec breathing volumes
What happens to PaCO2 while sleeping?
Does it change during REM vs NREM
Inc by 2-8 mmHg
Higher end during REM
What happens to PaO2 during sleep
Decreases by 3-10 mmHg
What happens to Oxygen demand during sleep
decreases by 15-25%
What happens to SaO2 during sleep
dec by 2%
Where are the chemo receptors
Central- Medulla
Peripheral- Carotid body, Aortic arch
What does the central chemorecptor sense
PaCO2 (via pH)
what do the peripheral chemoreceptors sense and what are they innervated by
PaO2 is the main stim but also respond to PaO2
Carotid body is innervated by CN IX
Aortic Arch is innervated by CN X
Pulmonary sleep changes in Asthma
increased airway restriction= nocturnal bronchoconstriction
nocturnal cough
Pulmonary and blood chemistry sleep changes in COPD
Hypercapnia and Hypoxemia are already problems in these patients
during sleep SaO2 may drop between 10 and 35%
Pulmonary and blood chemistry sleep changes Diffusion problems ie ILD, CF
CO2 can diffuse fine by hypoxemia may be severe
What are indications for non invasive positive pulmonary pressure ventilation in COPD
Severe COPD with hypercapnia (PaCO2 < 55) during the day OR
>2 hospitalizations for hypercapnic respiratory failure with PaCO2 of 50-55 OR
SaO2<88% for more than 5 min while on nasal oxygen
What are indications for non invasive positive pulmonary pressure ventilation in restrictive lung dz or worsening neuromuscular dz
either with worsening symptoms
FEV < 50%
max inspiratory force < 60 cm H2O
Pickwickian syndrome
Obesity Hypoventilation syndrome
What is the pathology of Pickwikian syndrome
daytime hypoventilation b/c of obesity- chest mass limits chest wall excursion –> alveolar hypoventilation
Symptoms of hypoventilation
Hypersomnelence
Dyspnea
Hypoxemia with cyanosis, polycythemia, and plethora
Complications of pickwickian syndrome
Cor pulmonlae- hypoxemia mediated
peripheral edema
Will CPAP help in Pickwikian syndrome
NO
Definition of Apnea
Cessation of breathing for at least 10 seconds
Definition of hypopnea
30% dec in airflow for at least 10 seconds with 4% desaturation
what does RERA stand for
Respiratory associated Respiratory arousal
what is RERA
series of increased breathing with increased effort resulting in awakening
what is the respiratory disturbance index
Apnea’s+ hypponeas’s + RERA’s/ night
AHI- what does it stand for
what is it, and what is it used for
Apnea - Hypopnea index
Apnea’s + Hypopnea’s / night
used to determine severity of sleep apnea
What is a normal AHI
what are the different stages of sleep apnea
normal: AHI30
what is polysomnography
sleep study
Why do you use do a sleep study
determine if sleep issues are behavioral or pathological
Allows for documentation of latency, efficiency, arousals/ awakenings, timing and quantification of stages based on EEG
What monitors are used
EEG
EOG- REM vs NREM
EMG’s- muscle activity
respiratory monitors- SaO2, EKG, airflow
What are the two main categories of sleep apnea
Obstructive sleep apnea vs central sleep apnea
What is the key difference between obstructive sleep apnea and central sleep apnea
EFFORT
obstructive sleep apnea- want to breath but cant
central sleep apnea- lose drive to breath
Definition of obstructive sleep apnea
intermittent obstruction of airflow resulting in apnea or hypopnea
where does the obstruction in obstructive sleep apnea normally occur
oropharynx
Risk factors for obstructive sleep apnea
obese enlarged neck African American Smoking Craniofacial abnormalities- large: tonsils, adenoids, uvula, soft palate, nasal polyps, tongue Retrognathia Diabetes Alcoholic Fam Hx Hypothyroidism
Signs and symptoms of obstructive sleep apnea
Snoring
Excessive daytime sleepiness
morning HA (arteries in brain expand to bring more blood in)
personality changes
respiratory acidosis from chronic hypercapnia
Diagnosis of sleep apnea
must be done with polysomnography
AHI>5 with hypersomnelence
Treatment of obstructive sleep apnea
behavioral changes- sleep hygiene- regulating bed time and duration, avoiding noise, drugs, and alcohol before bed. comfy bed
avoid sleeping in a supine position
weight loss
CAPA
uvulopalatopharyngoplasty, septoplasty, tubinoplasty- have varying success
tongue base ablation in kids
Complications of obstructive sleep apnea
Cor pulmonale
Secondary polycythemia
systemic HTN
arrhythmias
Central sleep apnea- definition
Repeated apneic efforts without respiratory muscle effort
Symptoms- of central sleep apnea
similar to OSA excessive daytime sleepiness morning HA personality changes respiratory acidosis
Risk Factors for central sleep apnea
general seen in sicker people, but have a normal BMI
elderly men
CHF
Afib- smal emboli go to brain
prior stroke
endocrine abnomralities- acromegaly, hypothyroid
Renal failure
Manifestations of central sleep apnea
Cheyne Stokes breathing
Describe Cheyne strokes breathing
apnea –> CO2 inc –> increasingly faster and deeper breathing –> CO2 dec –> lose respiratory drive –> apnea
pathophysiology of central sleep apnea
alveolar hypoventilation –> hypercapnia, hypoxemia, acidemia
controller gain can magnify the response
if it is from a neurologic abnormality the feedback system in the brain may not be working properly
if CHF- feedback is delayed
what is controller gain central sleep apnea
compensatory release of catecholamines
diagnosis of central sleep apnea
same as obstructive
treatment of central sleep apnea
treat the underlying cuase
reduce overshoot which causes sudden hyperventilation with NIPPV
blunt control with benzos and narcotic
O2 and CPAP dont work great for this
