Sleep disordered breathing refers to conditions like obstructive sleep apnea that disrupt normal breathing patterns during sleep. Key factors that influence gas exchange in the lungs include the V/Q ratio and the oxygen dissociation curve. Treatment options for obstructive sleep apnea include CPAP/BiPAP devices, oral appliances, and surgeries like uvulopalatopharyngoplasty. Capnography and end-tidal carbon dioxide measurements provide important windows into a patient's ventilation.

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 Transport CO2 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 in  Sat% 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 baseline—Exhalation of CO2-free gas contained in dead space. B-C: Rapid, sharp rise—Exhalation of mixed dead space and alveolar gas. C-D: Alveolar plateau—Exhalation of mostly alveolar gas. D: End-tidal value— Peak CO2 concentration—normally at the end of exhalation. D-E: Rapid, sharp downstroke—Inhalation

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 Sustained low EtCO2 with good alveolar plateau Possible causes: Hyperventilation Hypothermia Sedation, anesthesia Dead space ventilation

23. Abnormal Capnography Elevated EtCO2 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 con’t… 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

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