1. Automatic Positive Airway Pressure For Sleep Related Breathing Disorders BY AHMAD YOUNES PROFESSOR OF THORACIC MEDICINE Mansoura Faculty Of Medicine

2. Several conditions can cause sleep related breathing disorders, including: Obstructive sleep apnea (OSA) syndrome in which inadequate ventilation occurs despite continued efforts to breath due to upper airway obstruction. Central sleep apnea (CSA) syndrome in which inadequate ventilation resulting from absent or diminished respiratory effort. Complex sleep apnea syndrome These patients have predominantly obstructive or mixed apneas during the diagnostic portion of the study but with use of CPAP or BPAP without a backup rate, they show a pattern of apneas and hypopneas that meets the definition of CSA. Sleep hypoventilation syndromes, 1-There is an increase in the arterial PaCO2 (or surrogate) to a value > 55 mm Hg for ≥ 10 minutes. 2. There is ≥ 10 mm Hg increase in PaCO2 (or surrogate) during sleep (in comparison to an awake supine value) to a value exceeding 50 mm Hg for ≥ 10 minutes.

4. Attended polysomnographic titration of PAP Treatment pressure is established by direct inspection of sleep and breathing parameters during attended polysomnographic recording while adjusting pressures to find a setting that essentially eliminates apneas, hypopneas,snoring and hypoventilation in all sleep stages and body positions. In addition to allowing direct observation by trained technologists to guide pressure selection, titration under attended polysomnography allows for interventions to adjust mask fit, eliminate leak, and help the patient adapt to the initial PAP experience.

5. Attended polysomnographic titration of PAP

6. Potential limitations of attended polysomnographic titration of PAP The cost and inconvenience of repeat PSG due to incomplete titrations, the potential bias of in- laboratory versus in-home environment, and the potential to prescribe pressures that are not suitable due to the inherent limited sampling introduced when titration takes place over only one, or in the case of split-night studies, one-half night of recording. Pressure requirements may change over time due to variability in weight, change in underlying medical conditions, or resolution of upper airway edema caused by repetitive apneas.

7. Automatic Positive Airway Pressure Intelligent devices with in-built microprocessors for detection and treatment of events of SRBD have gone by different names ranging from self- adjusting, to automatic, auto-adjusting, smart CPAP, and auto-titrating PAP (APAP). The purpose of APAP devices included the replacement of in-laboratory manual titration, reducing mean pressures to achieve better adherence, and adapting CPAP levels to changes in severity of OSA in response to changes in weight, sleep state,, and body position.

8. Advanced methods of titration More recently, devices have developed to differentiate central from obstructive apneas (using forced oscillation technique), identify Cheyne-Stokes respiration (by breath-by-breath changes in peak flow), identify hypoventilation (by measuring tidal volume or minute ventilation using calibrated flow sensors) and compensate for air-leaks (using sophisticated flow- based algorithms). Such signals are computed and analyzed instantaneously by a built-in microprocessor with preset hierarchical set of algorithms that will determine the rate and magnitude of pressure response.

9. Technology The functioning of APAP devices can be broken down into three components: sensing of events of SRBD (sensors), automated computing and analysis of the sensed signals (analysis), and hierarchal set of algorithms that will determine the action taken by the APAP device in response to the conditions exposed (effectors).

10. Automatic Positive Airway Pressure In the older generation of APAP devices, the sensors were simplistic and measured only the pressure inflections (vibrations) of a certain frequency and amplitude that were caused by snoring. The next generation of APAP devices became more sophisticated and were able to sense flow- based changes such as apnea, hypopnea, or inspiratory flow limitation based upon the inspiratory flow contour (i.e., flattening of the inspiratory flow waveform).

11. Auto-CPAP devices When used in the auto-titration mode, the devices are used by the patient for a period of time (one night to several weeks). Information stored in the device is transferred to a computer and can be used to select an optimal fixed level of CPAP for chronic treatment. When APAP devices are used for chronic treatment they have the potential advantage of delivering the lowest effective pressure in any circumstance (body position, sleep stage). The mean pressure for the night may be lower than a single pressure that would be effective in all circumstances (the prescription pressure). For example, higher CPAP is usually needed in the supine posture and during rapid eye movement (REM) sleep.

12. DEVICE CHARACTERISTICS The devices differ in the respiratory variables that are monitored and in the algorithms used to adjust the delivered pressure. The devices typically monitor one or more of the following: airflow (or motor speed), airflow profile (flattening), snoring (airway vibration), or airway impedance (forced oscillation technique). The algorithms used to adjust pressure are proprietary but determine if the delivered pressure should be increased or decreased. Depending on the type of respiratory event that is detected the delivered pressure is increased by a certain amount.

13. Open unrestricted airway

14. Silent partial airway obstruction

15. Noisy partial airway obstruction

16. Complete airway obstruction

17. Open unrestricted airway

18. DEVICE CHARACTERISTICS The S9 Series detects both obstructive and central sleep apneas (CSA). CSA detection uses the Forced Oscillation Technique (FOT) to determine the state of the patient’s airway during an apnea. When an apnea has been detected, small oscillations in pressure (1 cm H2O peak-to-peak at 4 Hz) are added to the current device pressure. The CSA algorithm uses the resulting flow and pressure (determined at the mask) to measure the airway patency.

19. 80-90% reduction in flow for 6 seconds results in a short pulse of pressure. Here, “obstructive apnea” really means “closed airway apnea” because inspiratory effort is not monitored.

20. DEVICE CHARACTERISTICS Typically, pressure changes occur slowly over several minutes to prevent pressure-induced arousals. If no respiratory events are detected within a certain time window the delivered pressure is slowly decreased. Thus, the lowest effective pressure is delivered. In some of the devices machine adjustment is available for various mask types and for the type of humidifier that is being used. Studies comparing different APAP devices provide evidence that devices from different manufacturers will not deliver the same pressure for a given clinical circumstance.

22. Problems of APAP algorithms The problems of mask/mouth leak and central apnea have provided a challenge for the designers of APAP algorithms. Mask/mouth leaks tend to raise the baseline flow delivered by blower units and diminish the variations in flow during inspiration and expiration. The resulting airflow signal may be interpreted as an apnea or hypopnea and prompt an increase in pressure that may further increase leak. To handle the leak problem many APAP units have algorithms that limit pressure increases when leak exceeds certain values or when increases in blower speed no longer result in increases in mask pressure. Other units have leak alarms that can prompt the patient to adjust the mask.

23. Problems of APAP algorithms Mouth leaks can be approached by using a chin strap or full-face mask. Algorithms often include limits on upward titration of pressure for apnea to avoid the delivery of high pressure for central apneas. For example, pressure is not increased above 10 cm H2O unless apnea is associated with snoring or airflow profile flattening.

24. Expiratory pressure relief Expiratory pressure relief EPR for Resmed and C-Flex, for Respironics are now available. These mode allow reduction in pressure during early expiration with a return to the current set pressure at end expiration. This feature could improve patient tolerance to pressure.

27. The leak and residual AHI are low. The 95th percentile pressure was 9.4 cm H2O. The patient was treated with a prescription pressure of 10 cm H2O

28. Technique of Auto-Titration High leak can result in many devices promptly increasing pressure until the upper pressure limit is reached. summary statistics can be displayed for a single night or multiple nights. Typically available information includes: 90th or 95th percentile pressure, median pressure, maximum pressure, maximum leak, median leak, and residual AHI.

29. Technique of Auto-Titration Usually either the 90th or 95th percentile pressure is chosen for the prescription pressure. However, simply noting one number can be very misleading. The clinician must first determine if the titration duration (amount of sleep on the device ) was adequate and if the residual AHI is reasonably low (AHI < 5–10/hour). Patients with suboptimal or inconclusive APAP titrations should have a repeat APAP titration or be referred for an attended lab PAP titration.

30. Technique of Auto-Titration High-residual AHI could be secondary to frequent central apneas, high leak, or too low maximum pressure limit. High leak could be secondary to inadequate mask seal or mouth leak if a nasal mask is being utilized. Patients with a high AHI and leak may undergo a repeat APAP titration after mask adjustment or change to a full- face mask (or addition of a chin strap) as indicated. A persistently high-residual AHI despite repeated attempts at APAP titration would be an indication of the need for a traditional manual PAP titration.

31. The leak is higher than ideal (> 0.4 L/s) at times. However, the residual AHI remained low. The 95th percentile pressure was 7.8 cm H2O. The prescription pressure was chosen to be 8 cm H2O.

32. The leak is very high. The pressure increased to the upper limit (16 cm H2O) and remained there for most of the night. The AHI was also elevated. This titration would need to be repeated with a better mask seal.

33. Recommendations APAP is not recommended to diagnose OSA. (Standard) Patients with CHF, significant lung disease such as COPD, patients expected to have nocturnal arterial oxyhemoglobin desaturation due to conditions other than OSA (e.g., obesity hypoventilation syndrome), patients who do not snore (either naturally or as a result of palate surgery), and patients who have central sleep apnea syndromes are not currently candidates for APAP titration or treatment. (Standard)

34. Recommendations APAP devices are not currently recommended for split-night titration. (Standard) Certain APAP devices may be used during attended titration with polysomnography to identify a single pressure for use with standard CPAP for treatment of moderate to severe OSA. (Guideline) Certain APAP devices may be initiated and used in the self- adjusting mode for unattended treatment of patients with moderate to severe OSA without significant co-morbidities (CHF, COPD, central sleep apnea syndromes, or hypoventilation syndromes). (Option)

35. Recommendations Patients being treated with fixed CPAP on the basis of APAP titration or being treated with APAP must have close clinical follow up to determine treatment effectiveness and safety. This is especially important during the first few weeks of PAP use. (Standard) A re-evaluation and, if necessary, a standard attended CPAP titration should be performed if symptoms do not resolve or if the APAP treatment otherwise appears to lack efficacy.(Standard)

36. Advanced Methods Of Titration

37. Advanced methods of titration Newer generation devices can can increase the IPAP alone in order to ameliorate obstructive events (Auto Bi- level PAP),correct hypoventilation (averaged volume assured pressure support [AVAPS], Intelligent Volume Assured Pressure Support (iVAPS ) or combat central apneas in patients with complex sleep apnea (Servo- Ventilation). Devices may also introduce a back-up rate to prevent central apneas and although in general they are not referred to as APAP devices, they function using similar principles and can be judged as the latest generation of APAP devices.

38. BiPAP Auto

40. Autobilevel positive airway pressure with a minimum EPAP of 6 cm H2O and a maximum IPAP of 25 cm H2O.

41. BiPAP AVAPS and VPAP™ ST with iVAPS

42. BiPAP AVAPS

43. Ideal body weight Estimated ideal body weight in (kg) Males: IBW = 50 + 2.3 for each inch over 5 feet. Females: IBW = 45.5 + 2.3 for each inch over 5 feet. Estimated adjusted body weight (kg) If the actual body weight is greater than 30% of the calculated IBW, calculate the adjusted body weight (ABW): ABW = IBW + 0.4(actual weight - IBW) The IBW and ABW are used to calculate medication dosages when the patient is obese. This formula only applies to persons 60 inches (152 cm) or taller.

44. Comparing BPAP and AVAPS (both in the ST mode) in patients with OHS. AVAPS resulted in a slightly higher ventilation and lower PaCO2 without any better sleep quality or quality of life measures compared with BPAP- ST. On AVAPS, the minute ventilation was greater than on BPAP but sleep quality was comparable between the two NPPV modes. When VT-BPAP is used, the purpose of a polysomnography PAP titration is to select a level of EPAP that eliminates obstructive events (obstructive apnea and hypopnea) and document that the device does deliver adequate tidal volumes. VOLUME-TARGETED BPAP

45. Intelligent Volume Assured Pressure Support ( iVAPS ) Intelligent. Automatic. Personalized. Maintain a preset target alveolar minute ventilation Monitors delivered ventilation Adjusts pressure support Provides an intelligent backup breath Two mechanisms independent of one another 1-Variable Pressure Support to guarantee Alveolar Ventilation 2- iBR: intelligent Back-up rate

46. Anatomical Dead space Inspired/expired air remaining in conducting airways Not involved in gas exchange Correlation between patient’s height and dead space (Vd) Height is used to calculate anatomical dead space (Vd) for each breath of air (Tidal Volume) Example dead space volume (Vd) : 120 ml for height 175 cm or 70 inches

47. Anatomical dead space in relation to height of the patient

48. As alveolar ventilation drops, iVAPS rapidly increase pressure support until target Va is reached, and as alveolar ventilation increase, iVAPS rapidly decrease pressure support.

49. Intelligent back up rate (iBR) stays out of the way at 2/3 spontaneous rate whenever the patient spontaneously triggers above 2/3 of the target. once the patient rate reach minimum back up rate (2/3 of the target ) iBR increase towards patient spontaneous rate to maintain alveolar ventilation.Once spontaneous trigering returns, iBR drops back to 2/3 of the target / spontaneous rate.

50. Auto-TriLevel The auto-TriLevel principle by Weinmann combines two proven types of therapy – auto-CPAP and BiLevel – into a synthesis that offers the most therapy effectiveness. Your benefits with these products: Therapeutically effective maximum and mean pressures that are lower than BiLevel with the same tidal volume for fewer side effects such as leakage. It‘s like a new titration every day – adjusts to patient‘s high variability. Effortless titration and monitoring.

51. Auto-TriLevel IPAP: inspiratory pneumatic splinting of the airways (ventilation) EPAP: easier exhalation at a low expiratory pressure level for a pleasant breathing sensation Additional end-expiratory pressure (EEPAP): required minimum pressure for adequate splinting of airways during phase when risk of collapse is highest PDIFF (Δ IPAP-EPAP): need- oriented ventilation support by means of changes between inspiratory (IPAP) and expiratory (EPAP) pressure levels

52. Auto-TriLevel Reduced mean and maximum therapy pressure under TriLevel: Results of a bench test comparison with BiLevel therapy. SOMNOvent auto-ST is the world‘s first automatic BiLevel device that permits goal-oriented therapy settings(SCOPES). With the combination of the autoTriLevel principle and the automatic trigger WMtrak, this device delivers the greatest effectiveness, reliability and breathing comfort – simply the fastest therapy results. Particularly for cases of complicated SDB, SOMNOvent auto-S, convinces with its intelligent combination of automatic BiLevel S therapy and auto-CPAP.

54. Auto-TriLevel Auto-bilevel spontaneous (SOMNOvent auto-S ). Auto-bilevel spontaneous/timed (SOMNOvent auto-ST ). Anti-cyclic modulated ventilation (SOMNOvent auto-CR ).

55. ASV is a variant of BPAP that was developed to treat Cheyne-Stokes central apnea. Both ASV and BPAP devices with a backup rate are approved for use with patients with central apnea and complex sleep apnea

56. ASV is BiPAP with a twist. The IPAP and EPAP can vary, depending on the patient's needs. In some ASV-type machines, the EPAP is fixed and only the IPAP changes; in others both can change. Basically, in ASV one or both pressures is continously adjusted, so that the ventilation delivered to the patient 'adapts' to the situation.

57. SomnoVent CR Respironics autoSV ResMed VPAP Adapt SVRespironics autoSVResMed VPAP Adapt SV

58. The top graph is pressure and bottom is flow. Note that EPAP is set at 5 cm H2O. The IPAP is variable. When central apnea ensues, the machine senses less air flow and ratchets up the IPAP, eventually reaching the pre-set limit of 15 cm H2O. The prescription for this patient would read: "IPAP 5, PS 3-10."

59. A peak flow target is established around the 4-minute average and the machine changes the air delivery as needed, to deliver 95% of the target, as shown below.

60. Dynamic pressure support inversely proportionate to peak flow

61. Periodic breathing treated with BiPAP auto SV

62. Trilevel ASV uses three different pressure levels over the course of the breathing cycle. The IPAP pressure provides the inspiratory splint and ventilation. Expiratory pressure is varied between a lower level at the start of expiration (EPAP) and a higher level at the end of expiration (EEPAP).

63. Home Ventilation

64. BiPAP A30 Ventilator For 24 Hours Use BiPAP A30 ventilator has been designed to combine ease of use with technology advancement to deliver enhanced therapy that adapts to patient’s condition. Being at home can work wonders so It delivers a smooth transition from hospital to home for chronic respiratory patients. Compatible with PSG Systems Optional Oximetry Module Intuitive, User Friendly & Colored Interface Integrated Heated Humidifier Graphical & Statistical Data Management on Encore Pro & Direct View Soft wares

65. SPECIFICATIONS: Modes CPAP, S, ST, PC, T, AVAPS AVAPS available on S, ST, PC, and T modes AVAPS Rate 0.5 to 5 cmH 2 O/min Target Tidal Volume from 200 to 1500 ml IPAP 4 – 30 cmH 2 O EPAP 4 – 25 cmH 2 O Breath Rate 0 – 40 BPM Inspiratory Time 0.5 – 3 sec Rise Time 1 (100 ms) – 6 (600 ms) Monitoring Pressure, Tidal Volume, Minute Ventilation, Respiratory Rate, I/E Ratio Weight 2.1 kg (with Power Supply) Noise Level < 30 dBA at 10 cmH 2 O Humidification System one Humidification & Dry Box technology Alarms Patient Disconnect, Apnea, Low Minute Ventilation, Low Tidal Volume, High Respiratory Rate

66. BiPAP A40 Ventilator BiPAP A40 comes with well-known and clinically proven Philips Respironics technology such as Auto-Trak, AVAPS and a Dry Box humidifier design. The device is capable of non invasive and invasive pressure ventilation, up to 40 cmH 2 O, providing treatment for your chronic respiratory insufficiency patients. The device features AVAPS-AE, the first fully automatic ventilation mode, designed to help clinicians during titration process, while maintaining comfort and therapy optimization at the lowest pressures.

67. BiPAP A40 Ventilator This new innovative ventilation mode helps in providing long term therapy compliance regardless of changes to the body position, sleep stages and respiratory mechanics. Detachable Battery with up to 5 Hours Backup AVAPS-AE Automatically Adjust Ventilation to the Patients Need Compatible with PSG Systems Optional Oximetry Module Intuitive, User Friendly & Colored Interface Integrated Heated Humidifier Graphical & Statistical Data Management on Encore Pro & Direct View Soft wares

68. SPECIFICATIONS Ventilation modes : CPAP, S, S/T, PC, T, AVAPS-AE Hybrid ventilation AVAPS (Average Volume Assured Pressure Support) AVAPS-AE IPAP 4 – 40 cm H 2 O EPAP 4 – 25 cm H 2 O Target tidal volume (when AVAPS enabled) 200 – 1500 ml Breath rate 0 – 40 bpm (4 – 40 bpm in T mode) Inspiratory time 0.5 – 3 sec. Triggering and cycling Auto-Trak,Sensitive Auto-Trak, Flow triggering. Rise time 1 (100 ms) – 6 (600 ms) Size 21.6 cm W x 19 cm L x 11.5 cm H Weight 2.1 Kgs (with power supply)

69. SPECIFICATIONS: Humidification System One humidity control and ‘Dry Box’ technology Alarms Patient disconnection Apnea,Low minute ventilation,Low tidal volume (with AVAPS/AVAPS-AE only),High RR Monitoring Pressure, tidal volume, minute ventilation, respiratory rate, leak, I/E ratio Battery back up Detachable battery module: 5 hours DC power source 12 VDC, 5.0 A (external battery), 24 VDC, 4.2 A (power supply) Data management Encore Pro 2 and Direct View software Compatible with oximetry module Advanced detection of residual respiratory events(Obstructed Airway Apnea, Clear Airway Apnea, Hypopnea, Periodic Breathing, RERA, Large Leak and Snore)

70. Finger tip pulse oximeter with adapter

71. Stellar 150 The Stellar 150 is intended to provide ventilation for non-dependent, spontaneously breathing adult and pediatric patients (30 lb/13 kg and above) with respiratory insufficiency, or respiratory failure, with or without obstructive sleep apnea. The device is for noninvasive use, or invasive use (with the use of the ResMed Leak Valve). Operation of the device includes both stationary, such as in hospital or home, or mobile, such as wheelchair usage.

73. Stellar provides the following modes CPAP mode—a fixed pressure is delivered. S (Spontaneous) mode—the device senses the patient breath and triggers IPAP in response to an increase in flow, and cycles into EPAP at the end of inspiration. The breath rate and the respiratory pattern will be determined by the patient. ST (Spontaneous/Timed) or PS (Pressure Support) mode—the device augments any breath initiated by the patient, but will also supply additional breaths should the patient breath rate fall below the clinician's set ’backup’ breath rate. T (Timed) mode—the fixed breath rate and the fixed inspiration time set by the clinician are supplied regardless of patient effort.

74. Stellar provides the following modes PAC (Pressure Assist Control)—the inspiration time is preset in the PAC mode. There is no spontaneous/flow cycling. The inspiration can be triggered by the patient when respiratory rate is above a preset value, or time triggered breaths will be delivered at the backup breath rate. iVAPS (intelligent Volume Assured Pressure Support)— designed to maintain a preset target alveolar ventilation by monitoring delivered ventilation, adjusting the pressure support and providing an intelligent backup breath automatically. The iVAPS therapy mode is indicated for patients 66 lb (30 kg) and above.

75. Pathology Defaults The Pathology Defaults offer a choice of disease-specific preset setting values to facilitate efficient commencement of therapy. You can select from four sets of respiratory system mechanics. Before use you will need to review the set parameters on the Clinical Settings screen.