Sleep disordered breathing and sleep apnea

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Transcript of Sleep disordered breathing and sleep apnea

  • 1.Sleep Disordered Breathing

2. Objectives

  • Understand CO2, O2 relationships in the lungs
  • Describe types of Sleep Disordered Breathing
  • Treatment options for OSA

3. Spontaneous Breathing

  • Diaphragm flattens
  • Thoracic cage increases in volume, intrathoracic pressure decreases
  • Negative pressure causes intake of air

4. Lung Unit

  • Alveoli and blood capillaries intertwine

5. Gas Exchange

  • Occurs at at alveolar-capillary membrane
  • Process of diffusion

6. O2 TransportCO2 Transport

  • Dissolved in blood
  • Bound to Hb
  • Dissolved 10%
  • Bicarbonate 60%
  • Carbamino compounds 30%

7. Diffusion affected by:

  • Thickness of membrane
    • Inflammation
    • Fibrosis
  • Surface area diminished
    • Emphysema

8. V/Q ratio relationship between blood flow to an individual alveoli and airflow to that alveoli

  • Shunt Unit
    • Perfusion with no ventilation
    • Alveoli receives blood supply, airflow blocked by mucous no gas exchange
  • Dead Space Unit
    • Ventilation with lack of perfusion
    • Blockage in bloodflow, wasted ventilation no gas exchange occurs

9. Dissociation Curve

  • The curve represents the relationship between oxygen and Hb, and the factors that affect the uptake and release of oxygen and the degree of saturation.

10. Dissociation curve 11.

  • Basic Principles of the Curve:
    • Increasing O2 tensions result inSat%
    • Flat portion of the curve (60 mmHg - 100 mmHg), large changes in PO2 result in very small changes in Sat%.
    • Steep portion of the curve (10 mmHg - 60 mmHg), small changes in PO2 result in large drops in O2 Sat%.

12.

  • Factors Altering HB Affinity for O2:
    • Ph
    • Temperature
    • PaCO2
    • Hemoglobin Variants

13.

  • Shifts of the Curve to the Right:
    • Results in a decreased affinity
    • Results in a decreased O2 transport capability (O2 content)
    • Aids in unloading of oxygen to the tissues
    • Extreme shifts are a disadvantage, because O2 content is so depleted the tissue oxygenation is severely impaired

14.

  • Shifts of the Curve to the Left:
    • Results in a increased affinity
    • Results in a increased O2 transport capability (O2 content)
    • Hinders unloading of oxygen to the tissues.

15. Capnography

  • The measurement and graphical display of the concentration of carbon dioxide in waveform format

16. EtCO2

  • Refers to the measurment of carbon dioxide concentration at the end of expiration

17. ETCO2 Assessment

  • CO2 measurement with each breath

A-B:A near zero baselineExhalation of CO2-free gas contained in dead space. B-C:Rapid, sharp riseExhalation of mixed dead space and alveolar gas. C-D:Alveolar plateauExhalation of mostly alveolar gas. D:End-tidal value Peak CO2 concentrationnormally at the end of exhalation. D-E:Rapid, sharp downstrokeInhalation 18. Wave form allows us to assess

  • alveolar ventilation
  • integrity of the airway
  • proper functioning of a mechanical ventilator or anesthesia delivery system
  • cardiopulmonary system
  • rebreathing

19. EtCO2 waveform

  • Earliest Detection of Hypoventilation and Apnea
  • Shows cessation of breathing before pulse oximetry would alert medical staff to a problem
  • Helpful if the patient is on supplemental oxygen

20. Why are dissociation curve and EtCO2 important?

  • Windows to ventilation and perfusion

21. Abnormal capnograms

  • Sudden loss of EtCO2 to zero or near zero Possible causes: Airway disconnection Dislodged ET tube/esophageal intubation Totally obstructed/kinked ET tube Complete ventilator malfunction

22. Abnormal capnograms

  • SustainedlowEtCO2 with good alveolar plateau
  • Possible causes: Hyperventilation Hypothermia Sedation, anesthesia Dead space ventilation

23. Abnormal Capnography

  • ElevatedEtCO2 with good alveolar plateau
  • Possible causes:Hypoventilation Respiratory-depressant drugs Hyperthermia, pain, shivering

24. ABG Values 28 88 50 60 7.38 COPD 22-26 94-99 35-45 80-100 7.40 Normal HCO3 SaO2 PCO2 PO2 pH 25.

  • Cyanosis (bluish coloring) occurs with a PaO2 reduction of 5 gm %

26. Hypoventilation

  • Causes retention of CO2
  • pH drop

27. Hyperventilation

  • Causes decrease of CO2
  • pH to increase

28. Hypoxic Drive

  • Normal drive- CO2 build up
  • COPD- low O2

29. Characteristics of Respiratory Events Not required Usually mild cyclic desats Crescendo-Decrescendo pattern Waz-wane May last 15-30 min or more Cheyne-Stoles Respiration Mandatory Not required Slight increase, may crescendo to end of event Slight decrease from baseline Respiratory Event Related Arousal Not required 4% required Yes 30% from baseline 10-120 sec, Longer hypo-ventilation Hypopnea Not required Common; not mandatory NO Absent Minimum 10 sec Central Apnea Not required Not required Yes Absent Minimum 10 sec Obstructive Apnea Arousal Desaturation Effort Airflow Duration 30. Treatment of OSA

  • CPAP
  • BiLevel
  • Auto-titration
  • Surgery
  • Oral Appliances

31. Goals of Treatment

  • Eliminate hypopnea/apnea
  • Eliminate snoring
  • Eliminate associated arousals

32. Goals cont

  • Eliminate associated desaturations
  • Maintain SaO2 > 90%
  • Increase Sleep Efficiency

33. Titration Techniques

  • Initiate at 4-5 cm
  • Increase 1-2 cm increments
  • Record each pressure for a minimum of 15 minutes
  • Record REM sleep while in supine position

34. BiPAP

  • Varying pressures; insp 4 cm > expiration
  • Initiate if:
    • Pt intolerant to CPAP
    • Optimal CPAP pressure > 15
    • Optimal CPAP pressure is associated with the occurrence of central apneas

35. Lung Volumes 36.

  • The use of CPAP / BiPAP increases FRC which in turn improves oxygenation

37. Surgical Options

  • Uvulopalatopharyngoplasty (UPPP)
  • Laser assisted uvulopalatopharyngoplasty (LAUP)
  • Genioglossal advancement
  • Maxillomandibular advancement

38. More surgical options

  • Nasal surgery
  • Tonsillectomy
  • Tracheostomy
  • Approximately 50% effective

39. Oral Appliances

  • Mandibular repostitioners
  • Tongue retaining devices
  • Palatal lifting devices

40. 41. 42.

  • Removable
  • Fitted by dentist
  • Treatment of patients with:
    • Snoring
    • Mild OSA

43. Identified Risks

  • Intraoral gingival, palatal, or dental soreness
  • TMJ Syndrome
  • Obstruction of oral breathing
  • Loosening or flaring of lower anterior teeth
  • Excessive salivation

44. Oral appliances, contraindications

  • Central sleep apnea
  • Severe respiratory disorders
  • Loose teeth or advanced periodontal disease
  • < 18 yrs of age