E D W A R D C L E M M O N S , D O
D I R E C T O R , M A R Y G R E E L E Y S L E E P L A B O R A T O R Y
N E U R O L O G Y , M C F A R L A N D C L I N I C
1 0 / 1 9 / 2 0 1 6
OSA: Where Are We and Where are We Going?
Obstructive Sleep Apnea
Sleep disordered breathing characterized by narrowing of the airway impairing normal ventilation during sleep
Prevalence of OSA
26% of adults between 30-70 years old
Primarily increasing due to the obesity epidemic
Much higher rates observed in bariatric surgery and stroke patients (60-80%)
Characteristics of the OSA patient
Obesity (BMI≥30) is an independent predictor of at least mild OSA, as compared to being of normal weight or overweight A 10% increase in body weight predicted a 30% worsening of AHI, whereas a 10%
decrease in body weight predicts a 25% improvement in AHI
If already obese, the 10% increase in weight was equivalent to a 6-fold increase in the odds of having moderate to severe OSA (AHI≥15)
Additional features more in OSA patients as compared to the general public include large tongue and tonsils, longer soft palate, shallow airway seen with micrognathia/retroganathia, large neck circumference (>17” in males)
Comorbid diseases that herald increased rates of OSA CAD, CHF, heart arrhythmias, refractory HTN, Type 2 DM, and PCOS
Consequences of Untreated OSA
Likely related to fragmented sleep, cyclic hypercapnia/hypoxia, intrathoracic pressure swings, and increased sympathetic activity with frequent apneas
Quality of Life issues – decreased concentration, excessive daytime sleepiness, fatigue, and poor quality sleep (insomnia), job-related and motor vehicle accidents, relationship discord (separate bed phenomenon)
Medical issues – Cardiovascular disease, CHF, arrhythmias, stroke, glucose intolerance, HTN, Depression/anxiety, GERD, Nocturia, Impotence, sudden death (although this is likely a product of the above)
Screening Our Patients
Screening measures include signs and symptoms, as well as subjective patient questionnaires (e.g. STOP-BANG, Epworth, etc.) Personally, I use Epworth and scores ≥10 are indicative of excessive daytime
sleepiness (EDS)
Inconsistent studies on which screen is superior
No correlation between screening scores and severity of OSA
Symptoms that are approved for evaluation for OSA – non-restorative sleep (insomnia), fatigue, EDS (screened or reported), witnessed gasping/apneas/choking, snoring, depression, uncontrolled HTN, stroke, CHF, cognitive dysfunction, new onset Afib I typically like to use 3 indications – most typically snoring, non-restorative sleep, and
EDS.
All right, my patient probably has OSA, what next?
Ordering the PSG
When ordering the PSG, please try to include indications for the testing as they will be placed in the report to be consistent with the complaints you are receiving from the patient and what is being reported on
The sleep lab provides the patient an extensive questionnaire that asks about these features to better understand their complaints prior to analyzing the sleep study
Ordering the PSG
From a technique standpoint in the lab, there is really no difference between ordering the Routine PSG and the Split PSG in EPIC.
Caveat: If your patient has previously had a diagnosis of OSA, and “lost” their CPAP, feel free to order the Split and in the comments note that fact, so that the patient can be aggressively managed (usually AHI>20) in lab to establish therapy, that they will probably need.
Indications for Split night therapy
Moderate to severe OSA after 2 hours of diagnostic PSG (AHI≥30)
At least 3 hours available for CPAP titration
Techs are monitoring for these indications and these are not predictable prior to starting the testing – thus no difference between the routine and split studies
Interpreting the PSG
The overnight techs are scoring obvious events on the fly to make sure we are efficiently managing the patients – looking for the indication for a split night study
The daytime scoring tech then evaluates the whole study looking for sleep-related breathing disorders, sleep-related movement disorders, and parasomnias. Scoring includes hypopneas, obstructive apneas, central apneas, and limb movements
Hypopneas – 30% decrease in flow with 4% desaturation of SaO2
Apneas – 90% decrease in flow >10 seconds in length
Interpreting the PSG
Finally, I review the study in its entirety including EKG, limb movements, breathing events, and EEG sleep patterns and establish the diagnosis.
Obstructive AHI ≥ 5 with 3 signs/symptoms or AHI ≥ 15 without symptoms (rare to end up in lab without symptoms) = OSA
Severity
AHI ≥5, but <15 = Mild
AHI ≥15, but <30 = Moderate
AHI≥30 = Severe
Interpreting the PSG
Other findings Periodic limb movement index > 15 = Periodic limb movements of sleep
70% correlation between elevated PLMs and clinical Restless Legs Syndrome
Central apneas with central AI ≥ 5 = Central apnea
However, Central apneas must be greater than half of all AHI to be diagnostic
Usually not seen until PAP therapy has been started
Sleep-related hypoxia/hypoxemia – SaO2 (without obstructions) ≤88% for ≥5 minutes of total sleep time
More rare findings
Bruxism (teeth grinding)
REM behavior disorder – seen usually in patients who have been diagnosed with Parkinson’s Disease
All right, my patient definitely has OSA, what next?
PAP Therapy
PAP therapy is the gold standard for treatment of OSA
Continuous Positive Airway Pressure (CPAP) 1 pressure value patients are
breathing in and out against
“The Reverse Vaccuum”
Acts as an air “stent”
Indicated for all varieties of OSA
Disadvantage is the patient who has significant variance in his positional needs
Auto CPAP
Auto CPAP is CPAP with a variable pressure head Min Pressure 4 cm of H2O (CWP), Max Pressure 20 CWP
Advantages Good for at home trials for those who cannot tolerate the sleep lab
Good for patients who have varied needs based on sleeping position
Can provide data following inadequate lab titrations seen sometimes in the split night setting
Disadvantages Does not change on a breath by breath basis – adjusts over 5 minute windows
typically or with 3 minutes of constant snoring
Patients have to have quick follow-up and tailoring of the settings to ensure compliance and benefit if done as a therapy trial
Bilevel Positive Airway Pressure (BPAP)
Two levels of pressure – IPAP (inspiratory)/EPAP (expiratory)
Min pressure 4 CWP, Max pressure 25 CWP, Min pressure support (PS) 2, Max PS 8-10 (depending on machine)
Improves patient comfort especially for those with many residual hypopneas without apneas
EPAP adjustments are for apneas
IPAP adjustments are for hypopneas
Bilevel Positive Airway Pressure (BPAP)
Advantages
Patient comfort – no longer breathing out against a hurricane
Typically improves mask leak
Pressure support and high max pressures allow for improved therapy if CPAP maxed out
Disadvantages
Requires in-lab titration with a lot of moving parts for the overnight techs to interpret
Worsens central apnea
Must have failed CPAP in some way – usually pressure intolerance vs. residual AHI on follow-up visit
Auto BPAP
BPAP with variable pressure heads Typically setup with variable EPAP with max and min PS, and IPAP Max Advantages
Patient comfort Typically improves mask leak Pressure support and high max pressures allow for improved therapy if CPAP maxed out Can provide data following inadequate lab titrations seen sometimes in the split night setting
Disadvantages Does not change on a breath by breath basis – adjusts over 5 minute windows typically or with 3
minutes of constant snoring Patients have to have quick follow-up and tailoring of the settings to ensure compliance and benefit
if done as a therapy trial Worsens central apnea Must have failed CPAP in some way – usually pressure intolerance vs. residual AHI on follow-up
visit
Other Non-Invasive Ventilation
Adaptive Servo Ventilator (ASV)
Used for central sleep apnea with Cheyne-Stokes Breathing
Serve-HF trial showed detriment in patients with severe heart failure and thus has fallen somewhat out of favor
If predominant OSA with central-type events, it is still being used
Average Volume Assured Pressure Support (AVAPS)
Used for persistent hypoventilators as seen with neuromuscular disease, obesity hypoventilation, and severe COPD with well treated OSA and persistent hypercarbia/hypoxemia
Similar to BPAP with backup rate
Other therapies
Conservative Measures
Positional therapy – studies have shown no consistent long term benefit to positional therapy in terms of correcting OSA
Tennis ball T-shirt or other higher priced entities
Weight loss – As mentioned earlier, improves AHI but rare to “cure” OSA
Avoidance of respiratory depressants (anxiolytics, EtOH) – benefits AHI and likely sleep maintenance insomnia, but again not curative
Other therapies
Surgical
Tonsillectomy – remains the treatment of choice in pediatrics <12, assuming evidence of tonsillomegaly or tight oropharynx
No similar benefit in adults or teenagers
Uvulopalatopharyngoplasty
Success rates vary between 10-30% in terms of improving sleep apnea
Excellent for primary snoring as often the excess tissue is the cause of the snoring
Can be beneficial if the obstruction is at the palate level
The highly variable levels of obstruction from tongue to windpipe have this being done far less
Other therapies
Oral Appliance Therapy (OAT), Mandibular Advancement Device (MAD)
Pulls the mandible forward to open the airway
DO NOT JUST BUY ONLINE
Should be fitted by a dental professional and be titratable
Requires preceding and following PSG to prove benefit
Only for mild to moderate apnea
Common Complaints
PAP therapy
Air Leaks
Skin Irritation
Claustrophobia
Tangled in the hose
Too Loud
Aerophagia (bloating)
Dry Mouth
Pressure intolerance
Surgical
Recurrent snoring/reflux through the nose – due to velopharyngeal insufficiency
No improvement
OAT/MAD
Jaw pain/TMJ
Tooth pain
My patients are unable to tolerate their therapy, now what?
Follow-up
Most of the PAP follow-ups, I have asked to see me to show benefit and compliance and meet their insurance standards
If you want to see your own patients, that is no problem, just let me know
At that follow-up, we discuss the therapy as well as try to come up with fixes for any PAP related complaints
Can include different interface (>200 masks both nasal and full face to choose from), better comfort measures (Nasal cushions, strap cushions, humidity), or undertreatment requiring additional pressure
Follow-up
Additionally, we often discuss other alternatives to PAP therapy as some people just plain do not like it
Anecdotally, CPAP compliance is higher in patients with severe OSA (likely due to perceived benefit), who have had alternatives discussed with them (both pro and cons) and who have an understanding of the resultant diseases due to untreated sleep apnea. Additionally, if the bed partner feels things are going better, then that also improves compliance.
What about the future of sleep medicine?
Home Sleep Apnea Testing (HSAT)
Insurance companies have been moving to promote HSAT as an alternative to PSG due to cost cutting measures.
Patients often like this idea due to being able to sleep at home and not travel to centers for PSG
Qualifying patients must have a high PPV of OSA (signs and symptoms of OSA with + screen) WITHOUT certain comorbidities Exclusions: Cardiopulmonary disease, neuromuscular weakness, chronic opiate use,
symptoms of additional sleep disorders (RBD, PLMs)
There is currently a division in the best way to start HSATs at most centers Purchase equipment (VAs) and train patients to use it appropriately for their study – increases
technical adequacy – inefficient, with increased upfront costs Hire it out to DME/HSAT companies who provide patients with instruction (written, video)
and are responsible for the equipment – significant variability in technical adequacy, but increased efficiency for providers (single form) with no equipment to manage and update
Home Sleep Apnea Testing (HSAT)
The Devil in the Details HSAT equipment costs are variable to purchase, and usually multiplied for consumables
(nasal cannula, batteries) or repairs, not to mention possible non-return by patients
Some patients don’t have the necessary ability or technical acumen to understand the setup at home
The “best” HSAT equipment data does not exist
If you shop it to a DME/HSAT provider, your studies are not interpreted (usually) by the local sleep physician who would read the in-lab
Should a study not be technically adequate or inconclusive (early results show this is more often the case due to patient technical issues), the patient will then be sent for an in-lab PSG, not adding to the cost for this work-up that insurance companies were trying to cut
Some HSAT/DME companies are now allowing the local providers to interpret their own HSATs
Cranial Nerve Stimulation
Hypoglossal Nerve Stimulator
Targets muscle tone of the throat to open the airway during sleep
Done by ENT trained in the implantation and titration of the device – University of Iowa and Mayo both doing it
3 patients currently implanted in Iowa
Developed with Dr. Soose, an ENT at University of Pittsburgh
Cranial Nerve Stimulation
Indications
Age > 22 years
Moderate to severe OSA (AHI 20-65)
Unable to use CPAP
ENT evaluation does not show complete concentric collapse at the palate
BMI <32
PAP Failure
AHI>20 despite CPAP
PAP Intolerance
<5 nights of use per week
<4 hours per night of use
Unwillingness to use it
QUESTIONS?
Thank you for your attention!
