CPAP for Obstructive Sleep Apnea

1. See Also
   1. Continuous Positive Airways Pressure (CPAP)
   2. Non-Invasive Positive Pressure Ventilation
   3. Sleep Study (Polysomnogram)
   4. Obstructive Sleep Apnea
   5. Bilevel Positive Airway Pressure (BIPAP)
2. Mechanism
   1. See Continuous Positive Airways Pressure (CPAP)
3. Indications
   1. See Continuous Positive Airways Pressure (CPAP)
   2. Obstructive Sleep Apnea
   3. Loud continuous snoring
4. Contraindications
   1. Central Sleep Apnea
5. Precautions
   1. CPAP will worsen Central Sleep Apnea
      1. Do not use CPAP empirically without Sleep Study
      2. Decreases respiratory drive
6. Approach: Sleep Apnea Management
   1. Equipment
      1. Nasal pillows or full Face Mask
      2. Small quiet air compressor
   2. Technique:
      1. Requires specially-designed, tightly fitting masks
      2. Mask should have pressure-limiting valves
   3. Dosing
      1. Usual dose: 6 to 12 cm H2O (Range: 3 to 20 cm H2O)
      2. Higher pressure (within range above) indications
         1. Heavier weight
         2. Short-thick necks
         3. More severe Sleep Apnea
   4. Optimize compliance
      1. CPAP is discontinued in 50% of Sleep Apnea patients by 1 year
      2. Encourage use at least 4 hours per night
      3. Reduce fluid intake in the evening to decrease bathroom breaks (CPAP often not reapplied after middle of night awakenings)
      4. Recommend CPAP units with embedded tracking to monitor usage
      5. Treat side effects as below to ensure continued use
7. Adverse Effects: Methods to improve compliance in Sleep Apnea
   1. Optimize mask fit for size and shape of face
   2. Utilize mask option patient finds most comfortable
      1. Full Face Mask
         1. Appears similar to Simple Oxygen Mask
      2. Nasal pillows
         1. Soft adapters fit within both nares
      3. Consider alternating methods
   3. Patient should follow-up to make CPAP adjustments
   4. Treat underlying nasal symptoms (e.g. nasal steroid)
   5. Humidify or cool inspired air
   6. Consider otolaryngology consult if CPAP not tolerated
8. Efficacy: Sleep Apnea
   1. First line, very effective Therapy
   2. Reduces coronary ischemia in those predisposed
      1. Peled (1999) J Am Coll Cardiol 34:1744-9 [PubMed]
   3. Reduces Blood Pressure in hypertensives
      1. Becker (2003) Circulation 107:68-73 [PubMed]
      2. Pepperell (2002) Lancet 359:204-10 [PubMed]
9. Management: Follow-up of CPAP monitoring in Sleep Apnea
   1. Snoring despite CPAP?
      1. Is CPAP pressure too low?
      2. Is there a leak at the interface?
      3. Is the patient sleeping with mouth open?
      4. Does the patient use excessive Alcohol?
   2. Weight change since CPAP was started?
      1. Reassess CPAP if weight gain exceeds 10%
      2. Consider overnight oximetry
         1. Calculate desaturation index = (4% desats)/hours
         2. Desaturation index <5 is normal
   3. When was CPAP last checked?
      1. Mask should be changed every 6 months
      2. Check blower every 12 months
   4. Is the patient still symptomatic?
      1. Is patient compliant with CPAP?
      2. Is the patient allowing enough time for sleep?
      3. Are there problems with Sleep Hygiene?
      4. Are other conditions keeping patient awake?
         1. See Insomnia
         2. Consider restless legs
      5. Other conditions making them sleepy (e.g. Narcolepsy)
   5. Problems with CPAP?
      1. Intollerant of air pressure
         1. Activate CPAP ramp up or increase ramp time (machine slowly builds to maximal pressure as the night progresses)
         2. Add a CPAP humidifier
         3. Consider a full CPAP Face Mask
         4. Consider specific devices (Auto-adjust, C-flex)
         5. Consider lowering CPAP pressure by 1-2 cm H2O
         6. Sleep center to calibrate device pressure
      2. Nasal congestion, Vasomotor Rhinitis or nasal dryness
         1. CPAP heated humidifier
         2. Consider Nasal Saline at bedtime
         3. Consider nasal steroid for congestion
         4. Consider intranasal Ipratropium for Rhinitis
      3. Mask or pillow leaks (typically noisy and uncomfortable with poor fit)
         1. Adjust the straps, pads
         2. Check that the device is not upside down
         3. Wash face at bedtime and wash device daily
         4. Sleep center to switch mask types for better fit
      4. Claustrophobia
         1. Wear mask when reading or watching television
         2. Sleep center to resize mask
      5. Patient pulls off headgear while asleep (very common)
         1. Add chin strap or adjust for better fit
         2. Use a disconnect alarm
         3. Contour pillows can comfortably support the mask with position changes in bed
      6. Difficulty initiating sleep
         1. See Sleep Hygiene
         2. Wear mask when reading or watching television
         3. Assess for other causes (e.g. restless legs)
         4. Newer Sedative-Hypnotics such as Ambien or Sonata are considered safe and will not significantly exacerbate Obstructive Sleep Apnea
      7. Dry Mouth
         1. Start or increase heated humidification
         2. Consider a chin strap (e.g. Puresom Ruby)
         3. Consider full Face Mask (covers nose and mouth)
         4. Consider artificial Saliva
         5. Avoid drinking water overnight as solution due to secondary Nocturia
            1. Difficult to get the CPAP reattached in the middle of the night
      8. Pressure Sores or skin breakdown from mask
         1. Consider topical skin protection (e.g. Moleskin, Comfort care pad, Remzzz's, sorespot)
         2. Consider Topical Ointment at pressure areas (e.g. aquaphor)
         3. Refer to CPAP vendor for different mask or nasal pillows (especially if mask leak)
10. Management: Medicare and Sleep Apnea
    1. Medicare covers CPAP on a rent-to-own over the first year
    2. Continued coverage of device requires follow-up and demonstration of compliance
       1. Face-to-face clinician follow-up is mandatory at 31 to 90 days and
       2. CPAP use in the first 1-3 months for at least 4 hours/night for 70% of nights over 30 consecutive days
          1. Device logs document exact periods of use
11. References
    1. Mallemat and Runde in Herbert (2015) EM:Rap 15(2): 7-8
    2. Marino (1991) ICU Book, Lea & Febiger, p. 379-80
    3. Olson (2012) Mayo POIM Conference, Rochester
    4. Bower (2000) Otolaryngol Clin North Am 33(1):49-75 [PubMed]
    5. Flemons (2002) N Engl J Med 347:498-504 [PubMed]
    6. Gozal (1998) Pediatrics 102:616-20 [PubMed]
    7. Owens (1998) Pediatrics 102:1178-84 [PubMed]
    8. Piccinillo (2000) JAMA 284:1492-4 [PubMed]
    9. Sliverberg (2002) Am Fam Physician 65(2):229-236 [PubMed]
    10. Victor (1999) Am Fam Physician 60(8):2279-86 [PubMed]
    11. Victor (2004) Am Fam Physician 561-74 [PubMed]
    12. Wickwire (2013) Chest 144:680-93 [PubMed]