obstructive sleep apnea how to order a sleep study? herbert m. schub,md chief, pulmonary diseases...
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Obstructive Sleep ApneaHow To Order A Sleep Study?
Herbert M. Schub,MDChief, Pulmonary Diseases
Highland Alameda County HospitalClinical Professor of Medicine, UCSF
Obstructive Sleep Apnea
• Obstructive Apneas,• Hypopneas,or Respira-• tory Effort Related• Arousals• Daytime Symptoms • Sleepiness, Fatigue,• Poor Concentration• Snoring, Resuscitative• Snorts (Witnessed• Apneas)
The Essentials to Qualify
• Symptoms:• Snoring• Witnessed Apnea• Daytime Somnolence &/or• Fatigue• Recent Weight Gain• Use of Steroids• Motor Vehicle Accidents
• Physical Findings:• Height• Weight• BMI• Neck size• Male:>17” or 43 cm• Female:>16” or 41 cm• Malimpati Index of• Oropharynx I-IV• O2 Saturation on RA• ABG if O2 Sat<95% RA• PFT’s (Spirometry if pCO2• >45 mm
Polysomnography
• EMG Chest & Abdomen• Airflow at Nose and
Mouth• EEG, EOG• Oxygen Saturation
• Cardiac Rhythm• Leg Movements
Polysomnography Terms
• Apnea• Cessation or less than• 30% air flow for at • least 10 secs, usually• assoc with > 4% decr• O2 Sat• Hypopnea • 30-70 % decr air flow
• AHI…Apnea Hypopnea • Index• Apneas +Hypopneas• per hour:• < 5 hour= normal• 5-14= Mild• 15-30=Moderate• >30=Severe• RDI…Respiratory Disturb-• ance Index
Polysomnograph TermsSPLIT NIGHT STUDY AFTER establishing an accurate measure of REM sleep, RDI, AHI, O2 desat, EKG abnlties THEN, get a proper fitting CPAP/BiPAP mask or other device & identify the minimum CPAP level that abolishes obstructive apneas/hypopneas, O2 desat,respiratory effort- related arousals(RERAs) Pressure needed usually 5-20 cm
TITRATION STUDY Dx OSA already established, but need study with CPAP from beginning of night to establish proper pressure and maskAUTO-PAP Automatically changes pressures based on the presence and/or absence of OSA May be used during in the unatt- ended home setting to determine a single pressure for home use
Home Based (Portable Monitoring)Testing for OSA
• 4 Types:• type 3: 4 variables:• Respiratory movement ,• Airflow• Heart Rate &/or EKG• O2 Sat• type 4: 1or2 variables:• O2 Sat• Airflow• Overnight Pulse Oximetry alone• is inadequate….sensitive but• NOT specific for cause
• Advantages:• Low cost/ OK for un-• complicated OSA &• titration of CPAP• Disadvantages:• Often underestimate AHI• (hours of true sleep???)• Type 4 can’t distinguish• Central vs OSA or hypo-• ventilation)• No measure Upper Airway• Resistance Awakenings• No measure Periodic Limb• Movement Awakenings
Management OSA in Adults
Behaviour Modification Losing weight if Obese Change Sleep Position (if OSA is positional) Abstain from Alcohol, CNS depressantsNon-surgical OSA therapy CPAP Bipap
• Surgical therapy• Reserved for Selective• patients in whom • CPAP/BiPAP was• ineffective• Exception when OSA• due to a clear-cut• surgically correctable• obstructing lesion• Pharmacologic Treatment• For patients with sym-• ptoms despite adequate• therapy
Nasal CPAP Therapy
Initially described 1981Most effective treatmentBlower unit that produces CONTINUOUS positive pressure airflowIncreases the caliber of the
airway in the retropalatal and retroglossal regions…
acts as a PNEUMATIC SPLINT
Medicare Guidelines Severe RDI (20-30) RDI 5-20 if symptoms or co-existent cardiovascular OSA with AHI >15 If AHI 5-15, CPAP only if excessive daytime somnolence,
hypertension or cardiovascular disease
BiPAP Therapy
Permits independent ad- justment of inspiratory and expiratory pressuresGenerally used in patients who cannot tolerate high CPAP Too expensive to be used as first-line therapy
Compliance no better than with CPAPOften used with Obesity- Hypoventlation Synd- rome-m Pickwickian
Oral Appliance Therapy
Act by Moving (pulling) the tongue forward or
by moving the mandible and soft palate anterior- lyMore than 40 Oas are
availableNot as effective as CPAP
For mild-to-moderate OSA who cannot tolerate
CPAP(and BiPAP) Therapy
Nasal Plugs….Provent
• Patch fits over nostrils• Holds 2 small plugs• Creates just enough air• pressure to keep air-• ways open at night• Far less intrusive than• CPAP • Approved by FDA 2008
• Requires new patch • every night…30 day• supply $65-$80• More expensive than • CPAP• Not covered by• Medicare• In one study, 1/3 not • used: severe nasal• allergies,mouth breath
Obesity Hypoventilation SyndromePickwickian Syndrome
• pCO2>45mm &NOT due• to COPD (severe),• kyphoscoliosis, neuro-• muscular • 95% OSA do NOT have• OHS• 95% of OHS have OSA• O2 Sat as routine screen• for OSA. If <95%, get• ABG• IF ABG pCO2>45, get• spirometry
• IF pCO2>45, & no severe • COPD (FEV-1 <50%
pred),• indicate on
“Assessment”• the probability of OHS• and need to use BiPAP,• rather than CPAP during• Split Night Study
Narcolepsy
• Clinical Syndrome• Daytime Sleepiness• Cataplexy• Hypnagogic Hallucin-• ations• Sleep Paralysis• Only 1/3 all 4 symp-• toms
• Loss of neuropeptides• orexin-A and –B• (hypocretin 1 and 2• from hypothalamus• Multiple Sleep Latency• Test (MSLT)• Only valid IF PSG =• at least 6 hrs sleep• the previous night• 4-5 opport to nap q2h• the day after the PSG
Restless Leg SyndromeCriteria
1.Urge to move legs... usually w/ discomfort2.Begin or worsen during rest/inactivity/lying etc3.Relieved by movement4.Worse in evening/nightSupportive criteria: a. Family history RLS b.+ response to dopaminergic c. Periodic Limb Movements during sleep with PSG
•
• PSG NOT necessary to make dx• Secondary RLS:• Iron deficiency• End-Stage Renal Disease• Diabetes Mellitus• Multiple Sclerosis• Parkinson disease• Pregnancy• Rheumatic Disease• Venous Insufficiency• Miscellaneous
Periodic Limb Movements Of Sleep
Sudden jerking leg move- ments…repetitive,highly stereotyped…typically involve extension of big toe/partial flex ankle, knee/hip..patient usually unaware…increase w/ageVAST majority of RLSTreatment UNNECESSARY if PLMS w/out sleep comp- laints
• PLMD (Disorder)• Partial or Total Arousal• from sleep & cause/• contribute insomnia/• daytime
drowsy/somn-• olence• Use same drugs as RLS