1. Obesity Hypoventilation Syndrome

2. Pickwickian Syndrome
Obstructive sleep apnea was called the Pickwickian syndrome in the past because Joe the Fat Boy who was described by Charles Dickens in the Pickwick papers had typical features with snoring, obesity, sleepiness and “dropsy”.

3. OHS: Definition Obesity (BMI 30 kg/m2) Hypercapnia (PaCO2  45 mmHg)
Sleep-disordered breathing
Thomas Nast, The Pickwick Papers

4. OHS: Clinical Presentation
Middle-aged
2:1 male-to-female
Extremely obese
Significant sleep-disordered breathing (fatigue, hypersomnolence, snoring, AM headache)

5. OHS: Epidemiology Prevalence among OSA: 10-20%
No clear ethnic or racial predominance
In USA, prevalence of OSAS among middle-aged men and women were 4% and 2% (Young et al)

6. OHS: Hypercapnia Increased CO2 production
Decreased respiratory drive (will not breathe)
Respiratory pump malfunction or increased airway compliance (cannot breathe)
Inefficient gas exchange

7. Obesity Chronic hypercapnia OSA
Upper airway resistance
Increased mechanical load and weak respiratory muscles
Leptin resistance
Acute hypercapnia during sleep
Blunted ventilatory response
Increased serum bicarbonate
Chronic hypercapnia
Mokhlesi, B et al., Recent Advances in Obesity Hypoventilation Syndrome, Chest

8. OHS: Lung Volumes
TLC
TLC TV
TV  
RV RV

9. OHS: Lung Volumes Volume TLC Lungs TLC Chest Wall FRC FRC   RV
Pressure

10. Mechanism of OSAS
The upper airway dilating muscles,like all striated muscles-normally relax during sleep.
In OSAS, the dilating muscles can no longer successfully oppose negative pressure in the airway during inspiration.
Apneas and hypopneas are caused by the airway being sucked and closed on inspiration during sleep.

11. Anatomy of OSA
NORMAL SNORING SLEEP APNEA

12. Symptoms of OSA,OHS Night time Snoring Witnessed apnoea
Frequent nocturnal awakenings
Waking up choking or gasping for air
Unrefreshed sleep
Restless sleep
nocturia
Dry mouth
decreased libido

13. Symptoms of OSA,OHS Daytime Early morning headaches Fatigue
Daytime sleepiness
Poor memory, concentration or motivation
Unproductive at work
Falling asleep during driving
Depression

14. Symptoms of Sleep Apnea Syndrome

15. Features of Excessive Sleepiness
Motor vehicle crashes
Work related accidents
Impaired school or work performance
Marital problems
Memory and concentration difficulties
Depression
Impaired quality of life

16. OHS,OSA & Cardiovascular Diseases
Uncontrolled HTN- 83% have OSAH; activation of sympathetic drive.
Acute coronary syndrome % has OSA
Cardiac arrhythmias mostly Af
Heart Failure
Sudden cardiac death
Stroke

17. OSA,OHS and DM
Patients from the sleep clinic with AHI>10 are much more likely to have impaired glucose tolerance and diabetes
(Meslier et al Eur Respir J 2003)

18. Diagnosis A good sleep history Assessment of obesity, oral cavity
Assessment of possible predisposing causes: HTN, hypothyroidism, acromegaly and
Polysomnography: gold standard tool

19. Polysomnography EOG - Electrooculogram EEG - Electroencephalogram
EMG - Electromyogram
EKG - Electrocardiogram
Tracheal noise
Nasal and oral airflow
Thoracic and abdominal respiratory effort
Pulse oximetry

20. Overnight PSG

21. Apnea-Hypopnea Index
Apnoea-hypopnoea index (AHI)= number of apnea/hypopnea per hour of sleep
AHI<5 Normal
AHI 5-15 Mild OSA
AHI Moderate OSA
AHI >30 Severe OSA

22. OHS: Treatment PAP (CPAP or BiPAP) Oxygen therapy Surgery
No standard protocol for titration
Oxygen therapy
Surgery
Tracheostomy
Weight reduction
Pharmacotherapy
Medroxyprogesterone
Acetazolamide

23. Behavioral Treatments
Attain an ideal body weight
Sleep on the side
Avoid sedative medication before sleep
Avoid being sleep deprived
Avoid alcohol before sleep
Elevate the head of the bed
Promptly treat colds and allergies
Avoid large meals before bedtime
Stop smoking

24. Body Position Strategies- Raise HOB Avoid supine position
Tennis ball in pajamas
Backpacks

25. CPAP Therapy Works as a pneumatic Splint
1st choice of treatment in moderate to severe OSAHS
Success rate %
Long term compliance 60-70%
Retitrate pressure if needed

26. Oral Appliances MAD □ Not as effective as CPAP, TRD
□ Not yet available in Iran
□ Appropriate first-line treatment for Mild OSA, primary snoring, upper airway resistance syndrome ( UARS )
□ Not as effective as CPAP,
52% OSA have AHI<10%
□ Young, non-obese
□ Second line therapy for moderate-severe OSA
□ Patient’s choice - Not tolerating / refuse to use CPAP, or are not surgical candidates
MAD
TRD

27. Medical Treatments Weight loss Pharmacological Oxygen therapy
Nasopharynegeal intubation
Nasal CPAP
BiLevel CPAP
Automatic CPAP
Oral Appliances
Atrial Pacing

28. Oxygen Therapy Improves oxygen saturation during sleep
May prolong apneic episodes
Reduces cardiac arrythmias
Useful additive treatment with CPAP
Rarely reduces apneic episodes
Can improve daytime sleepiness
May cause CO2 retention

29. Pharmacological Therapy
Protriptyline
Medroxyprogesterone
Fluoxetine
Antihistamines
Nasal Steroids
Theophylline
Acetazolamide
Modafinil
Magalang UJ et al, 2003

30. Conclusion
With the increasing problem of obesity, the impact of undetected OHS & OSAS as a public health burden cannot be undermined among our population,
It merits appropriate preventive and treatment strategies.

31. references
Mokhlesi, B., Tulaimat, A. (2007), “Recent Advances in Obesity Hypoventilation Syndrome”, Chest 132 (4),
Weinberger, S.E., Drazen, J.M., “Disturbances in Respiratory Function”, in Kasper et al (eds), Harrison’s Principles of Internal Medicine (16th Edition), New York: McGraw-Hill, pp
Guyton, A.C., Hall, J.E. (2000), Textbook of Medical Physiology (10th edition), Philadelphia: W.B. Saunders.