Sleep Disordered Breathing

Question 1

Flow through the upper airway during sleep can be predicted using a Starling resistor model, where flow through a tube is predicted by pressures and resistances upstream and downstream to the site of collapse. During an obstructive event, what is the relationship between the pressures at the site of airway collapse (Pcrit), upstream (Pus) to the site of collapse, and downstream (Pds) to the site of collapse?

Answer 1

Pcrit> Pus> Pds

Question 2

During a limited flow event. what is the relationship between the pressures at the site of airway collapse (Pcrit), upstream (Pus) to the site of collapse, and downstream (Pds) to the site of collapse?

Answer 2

Pus>Pcrit>Pds

Question 3

During non-limited flow, what is the relationship between the pressures at the site of airway collapse (Pcrit), upstream (Pus) to the site of collapse, and downstream (Pds) to the site of collapse?

Answer 3

Pus>Pds>Pcrit

Question 4

What are some of the causes for narrowing of the airspace?

Answer 4

1. Fat toungue
2. Recessed Jaw
3. Reflex driven muscle activation (is absent in sleep)

Question 5

What is the difference between Upper Airway Recruitment Threshold, Loop gain, and Arousal Threshold?

Answer 5

UART- Magnitude of stimuli ( - pressure, inc co2, dec o2) required to recruit upper airway dilator muscles to adequately overcome Pcrit

Loop Gain- magnitude of ventilatory response

Arousal Threshold- the Negative pressure required to trigger arousal.

Question 6

What are the 4 types of Sleep Disordered Breathing?

Answer 6

1. Snoring
   
   • Occasional snoring is universal
2. Upper Airway Resistance Syndrome
   
   • 9% of population
3. Sleep Apnea
   
   • 4% of men 2% of women
     
     • 85% obstructive
4. Cheyne-Stokes (present in 40-50% of pts with Heart Failure)
   
   • an abnormal pattern of breathing characterized by progressively deeper and sometimes faster breathing, followed by apnea.

Question 7

A 62 year old man presents to clinic with the chief complaint of daytime sleepiness for the past 6 months. He is unable to stay awoke while watching TV and his wife is concerned about his driving. His wife also states that he struggles to breathe during sleep. He has a history of HTN and diabetes. His BMI is 38 and neck circuimfrence is 56cm. Which diagnostic test would provide the definitive diagnosis for this patient?

A.Nocturnal oximetry

B.Serum TSH level

C.Multiple Sleep Latency Test

D.MRI of the head and neck

E.Polysomnography

Answer 7

Polysomnography:

Is the diagnostic test for OSA or (Obstructive Sleep Apnea). All underlined words or phrases are risk factors:

• Male
• Daytime sleepy
• Poor Driving
• apnea
• HTN and diabetes
• Obese

Question 8

Which of the following surgical procedures would be most appropriate and effective in an adult patient _with severe, life-threatening obstructive sleep apnea syndrome (OSA_S) and intolerance to CPAP therapy?

A.Uvulopalatopharyngoplasty (UPPP)

B.Tonsillectomy and adenoidectomy

C.Maxillomandibular advancement

D.Tracheostomy

Answer 8

D.Tracheostomy

–Indicated in patients with severe life-threatening OSA (severe sleepiness, cardiac arrhythmias, severe hypoxemia, severe hypoventilation, or cor pulmonale) who are intolerant or unresponsive to other types of therapy

Question 9

What is Positive Ariway Pressure? Why do we use it? What is the difference between CPAP and BiPAP?

Answer 9

PAP- Added pressure to prevent closure of airway.

CPAP- Constant pressure throughout cycle

BiPAP- Provides a different pressure for Inspiration and expiration

Question 10

How do oral appliances help sleep apnea? Which one is prefered in patients with jacked up hill-billy teeth?

Answer 10

Tongue Retainers and Mandibular Repositioners move the tongue forward and open up the airway.

Tongue Retainers are for pts with bad dentition.

Question 11

Going back to the multiple choice question, what do you need to know about the other options?

A.Uvulopalatopharyngoplasty (UPPP)

B.Tonsillectomy and adenoidectomy

C.Maxillomandibular advancement

D.Tracheostomy

Answer 11

• Uvulopalatopharyngoplasty (UPPP)
  
  • Less effective than CPAP, Later recurrence
• Tonsillectomy and adenoidectomy
  
  • Effective in children with OSA due to adenotonsillar enlargement
• Maxillomandibular advancement
  
  • Positve response rate of 90%, opens airway.
• Tracheostomy
  
  • Pts w/Severe life threatening OSA that are unresponsive to other therapy