obseity and sleep apnea Flashcards
what is OSA
apnea in the presence of respiratory effort
What is CSA
apnea in the absence of respiratory effort
what is mixed apnea
: 1st central, then
obstructive
Classification of BMI
Ideal weight: BMI 18.5-24.5
Overweight: BMI >25; obese: BMI >30
Morbid Obesity > 50
Underweight: BMI<18.5
BMi isn’t used for children
defintion of Sleep apnea
complete cessation of airflow for more than 10 sec. with or without presence of respiratory effort
Less than 10 apneic episodes/hr sleep is considered normal
definition of sleep hypopnea
> 30% reduction in airflow without cessation of breathing) in conjunction with a 1) 2% decrease in SpO2 desaturation or 2) arousal from sleep
defintion of respiratory effort related arousal
increasing respiratory effort for 10 seconds or longer leading to an arousal from sleep but one that does not fulfill the criteria for a hypopnea or apnea
what is Sleep apnea syndrome (SAS)
repeated episodes of apnea and/or hypopnea during sleep
- clinically significant hypoxemia
- sleep fragmentation
- daytime somnolence
how to diagnosis sleep apnea
A history from the patient and/or the patient’s bed partner; noting the presence of:
- Snoring
- Sleep fragmentation
- Periods of apnea during sleep
- Non refreshing sleep
- Persistent daytime sleepiness
follow by upper airway and PFT assessment
What anatomical changes can contribute to sleep apnea?
Abnormalities in the posterior pharynx include
A large uvula
Enlarged tonsils
A long soft palate
Redundant lateral pharyngeal walls
Macroglossia (enlarged tongue)
Presence of an overbite of the upper teeth with a posterior placement of the mandible
what does the patient blood work show in the diagonis of sleep apnea
Polycythemia
Reduced thyroid function
Bicarbonate retention
what test can confirm sleep apnea
Polysomnography (PSG)
In home portable monitoring
what is the relationship between pharyngeal tone and sleep
When awake pharyngeal tone is maintained by increased activity of the upper airway dilator muscles
sleep onset (REM) decrease this muscle activity
results in narrowing/closure of upper airway during
sleep
what is the result of upper airway narrowing without closure
snoring and hypopnea
what is the result of upper airway closure
apnea
under what condition does a snorer convert to apneic?
addition of alcohol
extreme fatigue
supine posture,
weight gain
wht are the risk factors for OSA
Things that cause a small or unstable pharyngeal airway
- onset of sleep
- upper body obesity
- tonsillar hypertrophy
- crowded hypopharynx, recessed chin (retrognathia or (micrognathia)
- link with allergies, sinusitis (upper airway edema)
what is the cardiopulmonary comprise due to?
hypertension due to:
1)intermittent hypoxemia and SNS activation
2)
hypoxemia (leads to pulmonary hypertension)
nocturnal arrhythmias ( b rady tachy syndrome,
bradycardia, a flutter, V tach , Atrioventricular
block (second degree, PVC, SVT
what is the complication of OSA?
Linked to increased risk of:
MI CHF (left or right) stroke cheyne stokes breathing often occurs in patients with CHF ( chemoreceptor response) or stroke
what measurement is included in a polysomnography record
- sleep stage and sleep disturbance
assessment (EEG, chin EMG, EOG, limb moment) - assessment of airflow
- respitrace: thoracic & abdominal movements
- cardiac monitoring : ECG & BP (pre/post)
- SpO2
- pCO 2 either with capnography or TcPCO 2
- apnea during REM
- Increase in frequency & severity
- Arousals prevent entry into REM properly
formula of the apnea hypopnea index (AHI)
of apneas and hypopneas / TST (hrs)
aka respiratory disturbances index (RDI)
how to classify AHI?
<5 events is normal, > 10 events is diagnostic > 20 30 events is moderate >40 events is moderate severe SAS >50 events is severe
what should the patient know about if they are dx with OSA?
educated about the risk factors natural history long term consequences of OSA. consequences of driving an automobile or operating other equipment or tools while sleepy.
What are the treatment of OSA
Nasal CPAP (1st line of therapy) Avoid alchohol and drug exercise changing sleep position and pillow surgical dental
how does CPAP help with OSA
involves the relief of airway obstruction by the use of constant
pressure by nasal mask or pillow
- splints the airway open
- need sleep study necessary to determine
appropriate level of pressure
what is the contraindiation of CPAP
bullous lung disease
severe left heart failure
hypotension
complication of CPAP
patient compliance abrasions sinus/ear infections eye irritations Nasal dryness Rhinitis
what is CSA
waning of respiratory drive;
both VT and RR
what cause CSA
- lower brainstem lesions,
- post polio syndrome, encephalitis,
neurodegenerative diseases (MD, MG,
GBS) - stroke
- C spine surgical complications
- primary hypoventilation syndrome (Ondine’s sydrome)
what is the deal with CSR CSA
cheyne stoke respiration with central sleep apnea occurs frequent;y in patient with HF because of respiratory control system instability
vetilation is due to the metabolic change rather than the behaviour respiratory control during sleep
Primary stimulation for ventilation is Paco2
what cause CSR CSA
apnea in premature
Cerebral vascular accident (Stroke)
high atitude breathing
what are Clinical Features of CSA
Headaches due to ↑CO 2
snoring is uncommon
excessive daytime somnolence
central apneas begin in stage 1 sleep
what is mixed or complex apnea
Central apnea occurs first followed by effort
to breathe, but airway obstruction inhibits gas
flow.
what is the treatment for OSA
Treatment: usually OSA treatment methods
