Noninvasive Ventilation respiratory failure Understand the - - PDF document

▶
noninvasive ventilation
SMART_READER_LITE
LIVE PREVIEW

Noninvasive Ventilation respiratory failure Understand the - - PDF document

Mar 13, 2024 153 likes •257 views

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

slide-1
SLIDE 1

7/10/2019 1

Noninvasive Ventilation and Airway Clearance Therapy

Deanna Diebold, MD July 11, 2019

Goals/objectives

  • Learn about options for noninvasive treatment of chronic

respiratory failure

  • Understand the importance of maintaining clear airways and

therapy options for airway clearance

Ventilator History

  • Iron lung (late 1920s)
  • Cuirass/”Pneumobelt”

Ventilator History

  • Invasive vent (1950s)
  • CPAP (1981)

1 2 3 4

slide-2
SLIDE 2

7/10/2019 2

Neuromuscular Diseases (NMD)

  • Result in progressive weakness of skeletal muscles
  • Rapid – Myasthenic crises, Guillain-Barre
  • Intermediate - ALS
  • Slow – Muscular dystrophies, SMA type 2
  • Other (post-Polio syndrome, kyphoscoliosis)

Neuromuscular Diseases (NMD)

  • Respiratory complications are the primary cause of morbidity

and mortality

  • Hypoventilation (Inspiratory muscles)
  • Airway protection (Bulbar muscles)
  • Airway clearance (Expiratory muscles)

Nocturnal Hypoventilation

  • 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

Nocturnal Hypoventilation - Screening with overnight oximetry

5 6 7 8

slide-3
SLIDE 3

7/10/2019 3

Nocturnal Hypoventilation

  • 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

NIV improves survival in DMD

  • 5-year survival improved from 8% (historical data) to almost

75% if patients started NIPPV when FVC <1 liter

Simonds et al, Thorax 1998;53:949–952

NIV improves survival in ALS

  • RCT – seemed to

favor patients with less bulbar involvement

Bourke SC, et. Al. Neurology. 2006;61:171-177

NIV improves survival in ALS

  • Retrospective

Cohort Analysis – Bulbar patients actually benefitted more

Berlowitz, DJ et al. J Neurol, Neurosurg, Psychiatry 2016;87:280-286

9 10 11 12

slide-4
SLIDE 4

7/10/2019 4

NIV improves QoL in ALS

Bourke SC, et al. Neurology. 2006;61:171-177

NIV in NMD

  • Prolongs survival
  • Improves QoL
  • Start at night – REM paralysis/hypoventilation
  • Progress to daytime use
  • OMV

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

13 14 15 16

slide-5
SLIDE 5

7/10/2019 5 NIV in COPD

Murphy, P et al. JAMA 2017 June 6; 371 (21): 2177-2186

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

NIV in COPD – Payment

  • Daytime pCO2 (on prescribed O2) >52 mmHg AND
  • Nocturnal oximetry </=88% for > 5 minutes on at least 2 LPM

O2

  • OSA/CPAP has been considered and ruled out (PSG not

required)

Airway clearance

  • Excessive secretions (CF, bronchiectasis)
  • Inability to close glottis (bulbar dysfunction)
  • Low TLC (inspiratory muscle weakness)
  • Low Peak Cough Flow (weak expiratory muscles, chest wall

deformity)

17 18 19 20

slide-6
SLIDE 6

7/10/2019 6 Airway Clearance HFCWO – “Vest” HFCWO – “Vest” Airway Clearance

21 22 23 24

slide-7
SLIDE 7

7/10/2019 7

Airway clearance

  • Oscillating PEP valve – “Aerobika”, “Acapella”
  • Requires intact muscle strength
  • Requires adequate patient cooperation

Airway Clearance

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

Breath stacking

25 26 27 28

slide-8
SLIDE 8

7/10/2019 8

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

Airway clearance - Goal Airway clearance - Goal

29 30 31 32

slide-9
SLIDE 9

7/10/2019 9

Airway clearance - Goal

Stehling et al. Chronic Resp Disease; 2015;12(1): 31-35 McKim et al, Arch Phys Med Rehabil; 2012(93) 1117-1122

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

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

33 34 35