Noninvasive Ventilation respiratory failure Understand the - PDF document

7/10/2019 Goals/objectives  Learn about options for noninvasive treatment of chronic Noninvasive Ventilation respiratory failure  Understand the importance of maintaining clear airways and and Airway Clearance therapy options for airway clearance Therapy Deanna Diebold, MD July 11, 2019 1 2 Ventilator History Ventilator History  Iron lung (late 1920s)  Cuirass/”Pneumobelt”  Invasive vent (1950s)  CPAP (1981) 3 4 1

7/10/2019 Neuromuscular Diseases (NMD) Neuromuscular Diseases (NMD)  Result in progressive weakness of skeletal muscles  Respiratory complications are the primary cause of morbidity and mortality  Rapid – Myasthenic crises, Guillain-Barre  Intermediate - ALS  Hypoventilation (Inspiratory muscles)  Airway protection (Bulbar muscles)  Slow – Muscular dystrophies, SMA type 2  Other (post-Polio syndrome, kyphoscoliosis)  Airway clearance (Expiratory muscles) 5 6 Nocturnal Hypoventilation Nocturnal Hypoventilation - Screening with overnight oximetry  Not tightly correlated with (upright) PFTs  REM-related atonia and hypopnea  Decreased CNS sensitivity to hypoxemia and hypercarbia  Onset is gradual, symptoms can be subtle  More frequent awakenings (nocturia)  Increased sleep time, daytime sleepiness  AM headaches  Orthopnea (especially in supine position)  Daytime dyspnea is relatively rare 7 8 2

7/10/2019 NIV improves survival in DMD Nocturnal Hypoventilation  5-year survival improved from 8% (historical data) to almost 75% if patients started NIPPV when FVC <1 liter  Formal diagnosis and NIV titration - PSG with transcutaneous CO2 monitoring  Depending on patient preference and underlying condition, empiric NIV also acceptable  Insurance requires:  Neuromuscular diagnosis AND no COPD  FVC <50% predicted OR  MIP < -60 cm H2O OR  Daytime pCO2 >45 mmHg OR  Nocturnal desaturation <88% for >5 minutes Simonds et al, Thorax 1998;53:949–952 9 10 NIV improves survival in ALS NIV improves survival in ALS  RCT – seemed to  Retrospective favor patients with Cohort Analysis – less bulbar Bulbar patients involvement actually benefitted more Bourke SC, et. Al. Neurology. 2006;61:171-177 Berlowitz, DJ et al. J Neurol, Neurosurg, Psychiatry 2016;87:280-286 11 12 3

7/10/2019 NIV improves QoL in ALS NIV in NMD  Prolongs survival  Improves QoL  Start at night – REM paralysis/hypoventilation  Progress to daytime use  OMV Bourke SC, et al. Neurology. 2006;61:171-177 13 14 Hypoventilation in COPD NIV in COPD  RESCUE Trial (2014)  NIV if hypercapneic >48 hours after “resolution” of ARF  Settings 20/5 cwp  No benefit to mortality or readmission  Trend towards improved HRQoL  Murphy et al (JAMA 2017)  NIV if hypercapneic > 2 weeks after ARF resolution  Settings 24/4 cwp  Significantly improved admission-free survival 15 16 4

7/10/2019 NIV in COPD NIV in COPD  Probably best in patients with persistent hypercapnia - >53 mmHg at least two weeks following exacerbation requiring NIV  Use fairly high IPAP settings, goal is to normalize pCO2 Murphy, P et al. JAMA 2017 June 6; 371 (21): 2177-2186 17 18 NIV in COPD – Payment Airway clearance  Daytime pCO2 (on prescribed O2) >52 mmHg AND  Excessive secretions (CF, bronchiectasis)  Nocturnal oximetry </=88% for > 5 minutes on at least 2 LPM  Inability to close glottis (bulbar dysfunction) O2  Low TLC (inspiratory muscle weakness)  OSA/CPAP has been considered and ruled out (PSG not  Low Peak Cough Flow (weak expiratory muscles, chest wall required) deformity) 19 20 5

7/10/2019 Airway Clearance HFCWO – “Vest” 21 22 HFCWO – “Vest” Airway Clearance 23 24 6

7/10/2019 Airway Clearance Airway clearance  Oscillating PEP valve – “Aerobika”, “Acapella”  Requires intact muscle strength  Requires adequate patient cooperation 25 26 Breath stacking Airway clearance in NMD  Cough peak flow (CPF)  >270 L/min adequate  <160 L/min inadequate  Maximal expiratory pressure (MEP)  >60 mmHg adequate  <45 mmHg inadequate  Muscles temporarily become weak during acute illness 27 28 7

7/10/2019 Mechanical Insufflation- Exsufflation Mechanical I-E  Settings probably +/- 40 cwp  Higher pressures if using via trach  Probably lower pressures and longer inspiratory times in bulbar ALS  Slight concern for barotrauma if underlying parenchymal lung disease 29 30 Airway clearance - Goal Airway clearance - Goal 31 32 8

7/10/2019 Airway clearance - Goal Recap/Conclusions  Noninvasive ventilation benefits patients with restrictive lung disease from neuromuscular weakness or chest wall deformities  Length of life  Quality of life  NIV may benefit patients with severe COPD and hypercarbia Stehling et al. Chronic Resp Disease; 2015;12(1): 31-35 McKim et al, Arch Phys Med Rehabil; 2012(93) 1117-1122 33 34 Recap/Conclusions  Airway clearance therapy – multiple options available  Use if too many secretions or too weak to cough up secretions  If weak, probably need MI-E or air stacking  Maintenance therapy in the absence of acute symptoms probably has benefit 35 9