WSS Fall 2018 Advanced Algorithms - Clinical Applications Average Volume Assured Ventilation (AVAPS) Auto Servo Ventilation (SV) Hank Hart BS, LPN Objectives Differentiate between BiPAP AVAPS and BiPAP autosv Advanced Identify the patient population that will benefit from BiPAP AVAPS Describe the titration protocol for BiPAP AVAPS Discuss why the patient population that will benefit from BiPAP AVAPS will not benefit from BiPAP autosv Advanced Best Match Non-Invasive Ventilation Consensus Conference in patients with neuromuscular disease recent reviews have cited the advantages of pressure targeted devices for comfort and their ability to compensate for leaks. pressure targeted systems are not able to guarantee a minimum minute ventilation. BiPAP AVAPS Patient Types Source: Consensus Conference Chest 1999: Clinical Indications for Noninvasive Positive Pressure Ventilation in Chronic Respiratory Failure Due to Restrictive Lung Disease, COPD, and Nocturnal Hypoventilation 1
Average Volume Assured Pressure Support (AVAPS) AVAPS is a feature that always drives the BiPAP unit to a set tidal volume Used for patients with changing respiratory needs Sleep Disordered Breathing and Hypoventilation Prevalence of obesity and hypoventilation Presidential Trivia Which US president suffered from sleep apnea and obesity hypoventilation syndrome? Relation between Obesity Hypoventilation Syndrome (OHS) and OSA I have lost that tendency to sleepiness which made me think of the fat boy in Pickwick. My color is very much better and my ability to work is greater. William Howard Taft 27 th President of the United States June 28, 1909 Thomas Nast s drawing of Fat Joe from Charles Dickens The Pickwick Papers 10 Self Reported Obesity by State Obesity Hypoventilation Syndrome: Epidemiology Prevalence of obesity: ~20 to 30% Prevalence among OSA: 10 to 20% Prevalence among adult obese: 10 to 20% No clear ethnic or racial predominance Mokhlesi B et al. Obesity Hypoventilations Syndrome, Sleep Breath. Jun 2007;11(2):117-24 Moklesi B et al. Proc Am Thorac Soc Vol 5. pp 218 225, 2008 This slide used with permission from Dr. Moklesi 2
Epidemiology Consequence of OHS Data from Laaban JP,Chailleux E. Daytime hypercapnia in adult patients with obstructive sleep apnea syndrome in France, before initiating nocturnal nasal continuous positive airway pressure therapy. Chest 2005;127:710 5; and Mokhlesi B, Tulaimat A, Faibussowitsch I, et al. Obesity hypoventilation syndrome: prevalence and predictors in patients with obstructive sleep apnea. Sleep Breath2007;11:117 24.) The data from Italy were provided by Professor Onofrio Resta from the University of Bari, Italy This slide used with permission from Dr. Moklesi 13 Increases Daytime symptoms Traffic incidents Morbidity Cardiovascular morbidities Acute submission of respiratory failure Pulmonary hypertension Mortality 20 to 70% Decreases quality of life Miller A, Granada M. In-hospital mortality in the Pickwickian syndrome. Am J Med. Feb 1974;56(2):144-50 OHS vs. Kyphoscoliosis Treatment Treatment of Obesity Hypoventilation Syndrome Masa, et al, The obesity hypoventilation syndrome can be treated with noninvasive mechanical ventilation,chest April 2001, Changes in Physiological Outcomes Variables OHS base OHS w/niv Kypho base Kypho w/niv PO 2 51 ± 10 64 ± 11 55 ± 6 65 ± 5 PCO 2 58 ± 10 45 ± 5 59 ± 11 45 ± 4 ph 7.36 ± 0.04 7.41 ± 0.03 7.35 ± 0.03 7.38 ± 0.02 FEV1 60 ± 12 61 ± 10 27 ± 11 30 ± 12 FEV1/FVC 80 ± 13 81 ± 10 84 ± 8 85 ± 11 TLC 86 ± 13 87 ± 15 48 ± 8 49 ± 9 Bi-level with Volume Assured Acts primarily as a bi-level pressure support device but is able to provide a constant tidal volume Automatically adjusts the pressure support level to maintain a consistent tidal volume IPAP will automatically increase or decrease to maintain set tidal volume Masa, et al, The obesity hypoventilation syndrome can be treated with noninvasive mechanical ventilation, Chest April 2001 3
AVAPS Clinical Benefits of Bi-Level with Volume Assured Automatically adjusts the pressure support level to maintain a consistent tidal volume IPAP will automatically increase or decrease Maintains ventilatory support and tidal volume during progressive ventilatory changes of the patient positional changes during sleep Alarms to indicate that tidal volume is not being maintained Clinical Study Average volumeassured pressure support in obesity hypoventilation: A randomized crossover trial RCT with crossover design of OHS who failed CPAP (failure defined as RDI>10 and TcCO 2 >45 mm Hg N=10 (mean age: 53.5; BMI: 41.6; PaCO 2 47.4; RDI 74) Randomized to BiPAP S/T or BiPAP AVAPS and after six weeks patients were crossed over to the other arm Results - PtcCO 2 during Sleep Storre JH et al, Average volume-assured pressure support in obesity hypoventilation: A randomized crossover trial Chest 2006; 130:815 Storre JH et al, Average volume-assured pressure support in obesity hypoventilation: A randomized crossover trial Chest 2006; 130:815 Conclusions Bi-level ventilation improved sleep quality in patients with OHS The addition of volume assurance (i.e., AVAPS) to BPV-S/T therapy resulted in a significant decrease of PtcCO 2, thus normalizing PtcCO 2 during sleep Suggested Titration Protocol for BiPAP AVAPS 1. Set Tidal Volume target 2. Set IPAPmin at 8 cm H 2 O 3. Set IPAPmax at 25 cm H 2 O 4. Set EPAP at 4 cm H 2 O 5. Set Rate at 8-10 BPM or 2 BPM below the patient s spontaneous rate 6. Set I-Time at 1.5 seconds or patient comfort 7. Set Rise time at 2 or 3 or patient comfort Three ways to choose a starting tidal volume with AVAPS 1. MD suggestion 2. Patient Comfort 3. Ideal body weight: 8 ml/kg* *AVAPS suggested tidal volume settings based on height and ideal weight Height (inches) 59 61 63 65 67 69 71 73 75 Ideal Weight (kg) 52.0 55.5 59.0 62.5 66.5 70.5 74.5 78.5 83 Storre JH et al, Average volume-assured pressure support in obesity hypoventilation: A randomized crossover trial Chest 2006; 130:815 8 ml/kg VT 420 440 470 500 530 560 600 630 660 4
Suggested Titration Protocol for BiPAP AVAPS Observe for Events Obstructive Events* Increase EPAP by 1 cm H 2 O Other** Hypopneas, RERAs, Snoring *Obstructive Event 2 obstructive apneas **Other 3 hypopneas, or 5 RERAs, or 3 minutes of loud, definite snoring ***Respiratory Event Appearance of, or worsening of, hypoventilation during sleep Respiratory Events*** Inadequate Tidal Volume increase the Tidal Volume target Inadequate Respiratory Rate increase RR by 2 BPM Inadequate Oxygenation increase EPAP Wait 5 minutes Clinical Case Study OHS and Volume Assured Case Study: Volume assured and obesity hypoventilation 55 year old male BMI = 35 Settings: S/T mode + volume assured ventilation Vt = 550 ml IPAP min = 7 cm H 2 O IPAP max = 25 cm H 2 O EPAP = 6 cm H 2 O Backup rate = 12 BPM Case Study: Volume assured and obesity hypoventilation Very good compliance Pressure support need decreased with time Case Study: Volume assured and obesity hypoventilation Case Study: Volume assured and obesity hypoventilation Decrease in IPAP over time Average IPAP at 9 cmh 2 O IPAP increases at night correlating with sleep stages and body position Stable tidal volume with a target of 550 ml Stable tidal volume 5
Conclusion Progressive evolution to a CPAP mode Still needs high pressures for deep sleep stages and to compensate for his body position Servo Ventilation Placed back on S/T mode with volume assured ventilation Servo ventilation patient types BiPAP autosv Advanced: Automatic Servo Ventilation Treatment for complicated breathing patterns such as: Central apnea, Complex apnea and Periodic Breathing such as CSR Provides non-invasive ventilatory support to treat adult patients with OSA and respiratory insufficiency caused by central and/or mixed apneas and periodic breathing. Built with existing RI proven technologies Digital Auto-Trak Algorithm that targets peak flow Encore Pro/Anywhere and Care Orchestrator for patient reporting BiPAP autosv Advanced: Automatic Servo Ventilation BiPAP autosv Advanced: Automatic Servo Ventilation Automatic Pressure Support Targets peak flow over a 4 min. moving window Adjusts inspiratory pressure breath to breath when necessary (to achieve targeted peak flow) Bi-Flex Comfort Wave Form Automatically adjusting EPAP Titrates to eliminate obstructive component Distinguishes between obstructed and clear (open) airway Enhanced automatically calculated back-up breath rate Based on patient s spontaneous breath rate OR Standard rates of 4 30 bpm 6
Link between sleep apnea, hypertension and cardiovascular diseases (CVD) OSA and Hypertension Mild OSA is a risk factor for hypertension 1 Patients with untreated OSA may be resistant to their antihypertensive medications 2 Meta-analysis showed that CPAP reduces blood pressure in patients with resistant hypertension and OSA 3 1 Bixler, et al., Association of Hypertension and Sleep Disordered Breathing, Arch Intern Med 2000 2. Logan et al, High prevalence of unrecognized sleep apnea in drug-resistant hypertension, J Hypertension, 2001 3 Ifitkhar IH et al. Effects of continuous positive airway pressure on blood pressure in patients with resistant hypertension and obstructive sleep apnea: a metaanalysis J Hypertens. 2014 Dec;32(12):2341-50. OSA and Hypertension The incidence of hypertension increases with severity of OSA Most importantly, compared with controls, the risk for new-onset hypertension was greater among all groups of patients with OSA who were untreated. Cardiovascular effects of OSA Repetitive obstructive events expose the circulatory system to stimuli that may contribute to the progression of CVD Negative intrathoracic pressure Increases: left ventricular transmural pressure venous return right ventricular afterload likelihood of atrial arrhythmias Reduces: stroke volume and cardiac output Autonomic dysregulation Sympathetic excess Parasympathetic withdrawal Kasai et al, Sleep Apnea and Cardiovascular Disease: A Bidirectional Relationship, Circulation, 2012 Marin JM et al. Association Between Treated and Untreated Obstructive Sleep Apnea and Risk of Hypertension. JAMA. 2012;307(20):2169-2176 OSA and Atrial Fibrillation OSA is common in patients with atrial fibrillation (AF) The adjusted odds ratio for the association between AF and OSA is 2.19 1 Patients with untreated OSA have a higher recurrence of AF after cardioversion than patients without OSA Appropriate treatment with continuous positive airway pressure (CPAP) is associated with lower recurrence of AF 82% recurrence in untreated OSA 42% recurrence in treated OSA with CPAP 2 Cardiovascular (CV) effects of CSA CSA is more likely a consequence, not a cause, of heart failure Can initiate further deterioration in cardiovascular function Sympathetic Nervous System Activation is increased Does not have the extreme effects of negative intrathoracic pressures like OSA 1 Gami, A.S., et al., Association of Atrial Fibrillation and Obstructive Sleep Apnea. Circulation 2004:110::364-367 2 Kanangala, R., et al. Obstructive Sleep Apnea and the Recurrence of Atrial Fibrillation. Circulation 2003:107:2589-2594 Kasai et al, Sleep Apnea and Cardiovascular Disease: A Bidirectional Relationship, Circulation, 2012 7
Impact of untreated OSA Cardiovascular mortality and morbidity in patients with OSA Total sample size =1651 men, over 10 years 264 normal (control group) 377 snorers (AHI <5) 403 untreated mild to moderate OSA (AHI 5 to 30 without EDS) 235 untreated severe OSA (AHI >30 or AHI >5 with EDS) 372 severe OSA with CPAP treatment of OSA (AHI >30, CPAP >4 hrs/day) CPAP compliance objectively measured Study outcomes: fatal and non-fatal cardiac events Study Results CV events over 10-year period Fatal events Non-fatal events Marin, J.M., et al., Long-term cardiovascular outcomes in men with obstructive sleep apnoea-hypopnoea with or without treatment with continuous positive airway pressure, Lancet 2005:365:1046-1053 Marin, J.M., et al., Long-term cardiovascular outcomes in men with obstructive sleep apnoea-hypopnoea with or without treatment with continuous positive airway pressure, Lancet 2005:365:1046-1053 Prevalence of OSA in patients with CVD Study Conclusion 1 Patients with severe OSA who were untreated had a significant increase in CV events (both fatal and non-fatal events) after 10 years Risk factor: 2.87 higher than normal 2 Patients with severe OSA had a significant reduction in CV events when their OSA was effectively treated (>4hours/night) with CPAP General population Females males Heart Failure patients Patients with CAD Patients with Myocardial Infarction Marin, J.M., et al., Long-term cardiovascular outcomes in men with obstructive sleep apnoea-hypopnoea with or without treatment with continuous positive airway pressure, Lancet 2005:365:1046-1053 The Aim of Servo Ventilation Treatment with Servo Ventilation Stabilize the unstable flow pattern Deliver pressure support only when needed Trigger mandatory breaths when needed Provide efficient pneumatic splint 8
The limitations of CPAP treatment in CSA and CSR Although CPAP was able to reduce AHI and increase LVEF, the CANPAP trial did not demonstrate a beneficial effect of CPAP on morbidity or mortality in patients with central sleep apnea and HF CPAP only produced a 53% fall in CSA w The limitations of CPAP treatment in CSA and CSR Successfully reducing the number of central breathing abnormalities during sleep may decrease their short- and long-term impact on the patient prognosis. Suppression of CSA in HF patients is the key to improving survival. Since only ~50% of patients had effective suppression of CSA on CPAP, other treatment modalities may be required in this patient group Bradley TD et al. CPAP for CSA and Heart Failure, N Engl J Med, 2005 Arzt M et al. Suppression of CSA by CPAP in heart failure, Circulation 2007 Servo ventilation for central sleep apnea Servo ventilation Effectively suppresses CSA in all patients studied (approximate 90% reduction) 1 Suppresses central, periodic, and mixed respiratory disturbances more effectively than CPAP 2 Better compliance observed when compared to CPAP 3 Improves quality of life and left ventricular ejection fraction (LVEF) vs. CPAP 3 Servo ventilation for central sleep apnea Adaptive servo ventilation improves cardiac dysfunction and prognosis in chronic heart failure patients with cheyne-stokes respiration. The present study is the first to show the beneficial effects of ASV on cardiac functional parameters, plasma BNP levels reduced mortality and rehospitalization rates. 1. Arzt M et al, Effects of dynamic bilevel positive airway pressure support on central sleep apnea in men with heart failure, Chest 2008 2. Randerath et al, Long-term auto-servo ventilation or constant positive pressure in heart failure and coexisting central with obstructive sleep apnea. Chest 2012;142:440-47 3. Kasaï et al. Effect of Flow-Triggered Adaptive Servo-Ventilation Compared With Continuous Positive Airway Pressure in Patients With Chronic Heart Failure With Coexisting Obstructive Sleep Apnea and Cheyne-Stokes Respiration, Circulation 2010 Yoshihisa A et al, Int Heart J 2011;52:218-223 Servo ventilation in CompSAS CompSAS: NPPV vs. Servo Ventilation Complex Sleep Apnea patients were randomized to Noninvasive positive pressure ventilations Servo ventilation During titration both NPPV and Servo ventilation Suppressed central and obstructive events Sleep parameters were not effected After 6 weeks, Servo ventilation was superior in suppressing CSA and OSA. In patients with CompSAS, Servo ventilation was the most effective therapy for normalizing breathing and sleep parameters 1 Servo ventilation, which provides both a minimum pressure to hold the airway open and a precisely calculated ventilatory assist to minimize cyclic hypoventilation and hyperventilation, has emerged as a leading treatment 2 Dellwig, et al, Randomized Control Trial of NPPV vs. servoventialtion in Patients with CPAP-induced Central Sleep Apnea, Sleep, Vol. 36, No. 8, 2013 1.Morgenthaler, et al. Adaptive servo ventilation versus noninvasive positive pressure ventilation for central, mixed, and complex sleep apnea syndromes, Sleep 2007 2.Kruzniar TJ et al. Treatment of complex sleep apnea syndrome. Neurol. 2008 9
Patient background and PMH Clinical Case Study 70 yr. old male with atrial fibrillation and daytime sleepiness Patient referred to sleep center for evaluation after completion of ESS with a score of 13 out of 24 PMH 70 yr old male BMI 27 kg/m 2 Atrial fibrillation s/p pacemaker implant 2+ pitting edema in legs Medication list Lasix QD Warfarin 56 Diagnostic sleep study results Sleep parameters Diagnostic study CPAP Titration N1 and N2 CPAP of 8 cm H 2 O Strong crescendo-decrescendo patterns with central apnea and hypopneas Sleep efficiency 73% Apnea-hypopnea index (episodes/hr) 44 1 min. cycle times are seen Central apnea index (episodes/hr) 10 Obstructive apnea index (episodes/hr) 19 Hypopnea index (episodes/hr) 14 Mixed apnea index (episodes/hr) 0 Diagnosis: severe sleep apnea that is both obstructive and central 57 58 CPAP study REM CPAP of 8 cm H 2 O During REM cycle, breathing pattern returns to normal which is common for patients with periodic breathing and CSR CPAP Titration Improvement in sleep efficiency with CPAP as compared to baseline However, there was a change in the amount of central events that occurred while not in REM sleep New study - Servo ventilation titration Sleep parameters CPAP study Sleep efficiency 89% Apnea-hypopnea index (episodes/hr) 28 Central apnea index (episodes/hr) 18 Obstructive apnea index (episodes/hr) 3 Hypopnea index (episodes/hr) 6 Mixed apnea index (episodes/hr) 2 59 60 10
Servo Ventilation Titration 10 minute capture You can see that during the session, the device detected upper airway instability and increased the EPAP automatically Servo Ventilation Titration 10 minute capture You can see during periods of periodic breathing, the pressure support and backup breath rate system helping to correct the patient s breathing pattern 61 62 Servo Ventilation Titration Results Sleep parameters Servo ventilation study Sleep efficiency 95% Apnea-hypopnea index (episodes/hr) 3 Central apnea index (episodes/hr) 1 Obstructive apnea index (episodes/hr) 0 Hypopnea index (episodes/hr) 2 Mixed apnea index (episodes/hr) 0 Prescription after this final study: Max pressure: 25 cm H 2 O PS min: 0 cm H 2 O PS max: 15 cm H 2 O EPAP min: 5 cm H 2 O EPAP max: 15 cm H 2 O Auto rate Bi-flex setting of 3 Suggested Titration Protocol for BiPAP AutoSV Results from case studies are not predictive of results in other cases. Results in other cases may vary. 63 Suggested Titration Protocol for BiPAP AutoSV CPAP at 10 cm H 2 O Set EPAP min at 4 cm H 2 O or patient comfort Set EPAP max 20 cm H 2 O Set PS min at 0 cm H 2 O or at patient comfort Set PS max to 20 cm H 2 O Set Max pressure to 25 cm H 2 O Rate to Auto Set Bi-Flex to patient comfort Patient on CPAP changed to BiPAP AutoSV CPAP at > 10 cm H 2 O Set EPAP min at 6 to 8 cm H2O or patient comfort Set EPAP max at highest level attainable Set PS min at 0 cm H2O or at patient comfort Set PS max at highest level attainable Set Max pressure to 25 cm H2O Rate to Auto Set Bi-Flex to patient comfort Bi-level with volume assurance (AVAPS) is NOT recommended for patients with periodic breathing Treatment of periodic breathing requires a variable breath-by-breath response system so the patients PaCO 2 stabilizes quickly Prevents overshooting or undershooting the PaCO 2 breath by breath Does not augment the patients tidal volume consistently Does not have a quick variable response to changes in tidal volume It is designed to adjust and maintain a constant tidal volume with each breath over time This benefit often seen with patients who have slow declines in their ventilatory conditions 11
Should you use auto Servo ventilation for a neuromuscular disease? NO! Would continually reset it is baseline, worsening the hypoventilation Normal target continues to decrease continues to under ventilate patient as the night progresses Ventilation Summary Sleep Disordered Breathing is associated with Cardiovascular diseases (CVD) Obesity hypoventilation syndrome (OHS) Untreated OSA may increase risk for CV events Effective CPAP use can reduce CV events in patients with severe OSA Servo Ventilation is the treatment modality for periodic breathing seen in patients with CVD AVAPS - Volume assured is the treatment modality for respiratory insufficiency / hypoventilation such as OHS Time Thank You! 12