Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

New modes of mechanical ventilation TRC


Published on

Published in: Education
  • dear wessel
    if you have a ryles tube in NIV does it become invasive ventilation-no- the NAVA catheter is also placed into the esophagus doubles as Ryles tube, respiratory infection with ryles tube/NAVA catheter is almost same-hope it answers your question
    Are you sure you want to  Yes  No
    Your message goes here
  • in slide 23 you mention NAVA - emerging evidence even in children and NIV.. The moment you insert a tube/catheter to assist with ventilation then you are not administering NIV but 'Mask-ventilation'. NAVA cannot be classified as NIV because you have a catheter placed invasive, NAVA does not comply with the basic principle of NIV: reduce infection!
    Are you sure you want to  Yes  No
    Your message goes here

New modes of mechanical ventilation TRC

  1. 1. Newer modes of Mechanical Ventilation Dr. T.R. Chandrashekar Director Critical Care K.R.Hospital Bangalore
  2. 2. Outline of the talk <ul><li>Which modes qualify as newer modes? </li></ul><ul><li>Why newer modes were introduced ? </li></ul><ul><li>Let us conceptualise the newer modes </li></ul><ul><li>My classification of newer modes </li></ul><ul><li>Do we require them? Evidence base </li></ul><ul><li>A few important modes- I will discuss </li></ul><ul><li>VAPS, PAV+, APRV/BIPAP, Smartcare </li></ul>
  3. 3. SIMV PCV ACV CMV Basic Modes? PS Newer [Alternative] Modes ? Volume support (VS) Volume Assured Pressure Support (VAPS) Pressure regulated volume control ventilation (PRVC) Mandatory minute ventilation (MMV) PROPORTIONAL ASSIST VENTILATION(PAV) ADAPTIVE SUPPORT VENTILATION(ASV) Smartcare/Automatic tube Compensation BIPAP/DUOPAP Airway pressure release ventilation (APRV ) High Frequency Ventilation/oscillation Partial Liquid Ventilation (Perflurocarbon) Neurally Adjusted Ventilatory Assist (NAVA) Fractal ventilation
  4. 4. What are Physicians Doing? 1,638 patients in 412 ICUs 47% Assist-Control Ventilation 46% Pressure Support and/or SIMV 7% Other Variability in modes across nations No variability in settings Esteban et al, AJRCCM 2000; 161:1450-8
  5. 5. Modes of Ventilation during Weaning Esteban et al, AJRCCM 2000;161:1450 PS SIMV + PS Intermittent SB trials Others SIMV Daily SB trials Number of ventilated patients, (%)
  6. 6. Why New Modes? <ul><li>Address important clinical issues: </li></ul><ul><ul><li>Poor trigger </li></ul></ul><ul><ul><li>Proportional assist to match patients effort </li></ul></ul><ul><ul><li>Improve patient - ventilator synchrony! </li></ul></ul><ul><ul><li>More rapid weaning! </li></ul></ul><ul><ul><li>Less likelihood of VILI </li></ul></ul><ul><ul><li>Less hemodynamic compromise </li></ul></ul><ul><ul><li>More effectively ventilate/oxygenate! </li></ul></ul>Satisfies our craving for adventure - (engineers and clinicians) We like better numbers - (seduction by pulse oximetry)
  7. 7. <ul><li>Why newer modes were introduced ? </li></ul><ul><li>Let us conceptualise the newer modes </li></ul>
  8. 8. Striving for better outcomes: <ul><li>The three </li></ul><ul><li>• S pontaneous breathing (Girard 2008; MacIntyre 2000, Levine 2008) </li></ul><ul><li>• S ynchrony (Chao 1997;Thille 2006; De Wit 2009) </li></ul><ul><li>• S edation management (Kress 2000, Girard 2008, De Wit 2009) </li></ul>“S”s All reduce time on mechanical ventilation Nearly 50% time is spend on weaning
  9. 9. Phases of ventilatory cycle Delay, Missed breaths Fatigue/VIDD/runaway
  10. 10. Old modes trigger delay
  11. 11. Trigger in conventional modes We are targeting the last part of the cycle and Also add the delay from the Y piece or the machine end Trigger delay is inbuilt in the old modes
  12. 12. NAVA Esophagus
  13. 13. Sinderby et al, Nature Med 1999;5:1433 Time (s) 0 1 4 3 2 0 1 4 3 2 Airway Pressure Trigger Onset of diaphragmatic electrical activity Onset of ventilator flow Neural Trigger 0 20 -5.0 0.0 0.0 0.5 -1 0 1 Flow (l/s) Volume (l) P es (cm H 2 O) P aw (cm H 2 O ) Missed breaths
  14. 14. PAV+ vs. PCV /PSV example PCV 15 cmH2O PAV+ at 75% Compared to PCV, the PAV+ mode better matches patient’s effort to ventilator output. PAV+ P T P T P T P T P T P T Proportional support has synchronised inspiration to expiration cycling
  15. 15. These can lead to disuse atrophy of the respiratory muscles (VIDD) or lowering of the CO 2 set point. Either case can delay weaning and result in more ventilator days! or M Younes. Proportional Assist Ventilation, A New Approach to Ventilatory Support. Theory. Am Rev Respir Dis 1992;145:114-120. The practitioner’s typical response to an increase in demand is what? we need to select a level of pressure support that is “ not too low, not too high, but just right”. Proportional support to patients effort which can change from breath to breath is ideal Increase support Sedate
  16. 16. Proportional support is vital No Diaphragm activity Missed breaths Possibly to much pressure support which had suppressed the diaphragmatic activity Increase the PS
  17. 17. Automated mechanical ventilation is the future <ul><li>A growing number of medical errors in the literature related to </li></ul><ul><ul><li>Workload </li></ul></ul><ul><ul><li>Due to the shortage of personnel </li></ul></ul><ul><ul><li>High frequency of severe ‘burnout syndrome’ among physicians and nurses working in ICUs. </li></ul></ul><ul><ul><li>High frequency of staff turnover </li></ul></ul>
  18. 18. Automated mechanical ventilation is the future <ul><li>In the study by Donchin et al , </li></ul><ul><li>Average number of activities per patient per day was 178 </li></ul><ul><li>Activities related to breathing were the most frequent </li></ul><ul><li>(26% of all activities) </li></ul><ul><li>An estimated mean number of errors per patient per day was 1.7 </li></ul><ul><li>Errors related to breathing were the second most frequent </li></ul><ul><li>(23% of all errors), after errors related to data entry </li></ul>
  19. 19. The Future of Mechanical Ventilation <ul><li>Advanced closed-loop systems -Reduce the staff workload and to reduce the duration of MV </li></ul>What is a Closed Loop Ventilation ? Automated mechanical ventilation is the future
  20. 20. Closed Loop Ventilation Ventilator Patient Clinician Open Loop Ventilation Basic modes- PS/SIMV/CMV Set volume/presuure/flow Patient has to adapt to the ventilator Gets feedback on lung resistance/compliance Adapts to the patient- ASV/PAV+/NAVA Smartcare Intensivists brain
  21. 21. My classification of new MODES <ul><li>Dual modes </li></ul><ul><li>Which combine Volume mode + Pressure modes- </li></ul><ul><li>VS, MMV, VAPS, PRVC etc… </li></ul><ul><li>Modes which adapt to lung characteristics </li></ul><ul><li>( Resistance & Compliance) PAV+, ASV </li></ul><ul><li>Spontaneous breathing + higher FRC- APRV/ BIPAP </li></ul><ul><li>Knowledge based Weaning modes- Smartcare, ATC, PAV, ASV, NAVA </li></ul><ul><li>Better trigger mechanism- NAVA </li></ul>
  22. 22. Arguments Against New Modes <ul><li>Lack high-level evidence for better patient outcomes </li></ul><ul><li>If we try a new mode and the patient has a good outcome, we say it was due to the new mode. </li></ul><ul><li>But if try a new mode and there is a bad outcome, we say the patient was going to die anyway. </li></ul><ul><li>Potential for harm (these are often not reported) </li></ul><ul><li>Improved gas exchange does not necessarily improve </li></ul><ul><li>outcomes: high tidal volume, iNO, prone </li></ul><ul><li>New is not necessarily better </li></ul><ul><li>Solution to a problem or in search of a problem? </li></ul>
  23. 23. Better oxygenation, faster weaning, lesser sedation, less Asynchrony YES- BUT mortality benefit not proved <ul><li>Dual modes most popular but no great evidence </li></ul><ul><li>BIPAP no great evidence </li></ul><ul><li>NAVA -emerging evidence even in children and NIV </li></ul><ul><li>ASV- physiological mode –accumulating evidence (ARDS/COPD) </li></ul><ul><li>PAV +-better than PAV, physiological mode –accumulating evidence, NIV good evidence </li></ul><ul><li>Smartcar e-unique mode can say ventilator has intensivist’s brain-good evidence for weaning </li></ul>
  24. 24. I will discuss these modes <ul><li>Dual modes- VAPS – </li></ul><ul><li>PAV+, </li></ul><ul><li>BIPAP </li></ul><ul><li>Smartcare </li></ul>VS/PRVC/MMR/MMV etc.. ASV /APRV / ATC/NAVA
  25. 25. DUAL MODES
  26. 26. Lung Compliance Changes and the P-V Loop Volume (mL) PIP levels Preset V T P aw (cm H 2 O) Volume Targeted Ventilation COMPLIANCE Increased Normal Decreased
  27. 27. Volume Control : good and bad <ul><li>Guaranteed tidal volume- even with variable compliance and resistance. </li></ul><ul><li>Less atelectasis compared to pressure control. </li></ul><ul><li>Can cause excessive airway pressure-VILI </li></ul><ul><li>The limited flow available may not meet the patient’s desired inspiratory flow rate-asynchrony </li></ul><ul><li>Leaks = Volume loss </li></ul>
  28. 28. Lung Compliance Changes and the P-V Loop Volume (mL) Preset PIP V T levels P aw (cm H 2 O) COMPLIANCE Increased Normal Decreased Pressure Targeted Ventilation
  29. 29. Pressure Control : good and bad <ul><li>• Limits excessive airway pressure </li></ul><ul><li>• Improves gas distribution </li></ul><ul><li>• Less VT as pulmonary mechanics change-atelectasis </li></ul><ul><li>• Potentially excessive VT as compliance improves </li></ul>
  30. 30. <ul><ul><li>1.Set Tidal Volume </li></ul></ul><ul><ul><li>With </li></ul></ul><ul><ul><li>2. Safer Pressure Limit </li></ul></ul>Target
  31. 31. 60 -20 60 Flow L/min Volume Switch from Pressure control to Volume control L 0 0.6 40 VAPS-Volume assured Pressure Support Normal PS If Compliance decreases P aw cmH 2 0 Set tidal volume cycle threshold Set pressure limit Tidal volume met Tidal volume not met Flow cycle
  32. 32. Dual Modes <ul><li>Volume target achieved-can target a pressure limit </li></ul><ul><li>Issues not addressed </li></ul><ul><li>Trigger delay </li></ul><ul><li>Proportional support-VIDD/fatigue </li></ul><ul><li>Not taking into account lung mechanic’s resistance/compliance </li></ul><ul><li>Not physiological -asynchrony </li></ul>
  33. 33. PAV +(Proportional Assist Ventilation) <ul><li>Provides pressure, flow assist, and volume assist in proportion to the patient’s spontaneous effort, the greater the patient’s effort, the higher the flow, volume, and pressure </li></ul><ul><ul><ul><li>The operator sets the ventilator’s volume and flow assist at approximately 80% of patient’s elastance and resistance. The ventilator then generates proportional flow and volume assist to augment the patient’s own effort </li></ul></ul></ul>
  34. 34. PAV+ uses the compliance and resistance information collected every 4-10 breaths to know what it’s fighting against . PAV+ uses the flow and volume information collected every 5 milliseconds to know what the patient wants. PAV+ combines this data with the %Supp information input by the clinician to determine how much pressure to supply to the system. PAV+
  35. 35. The clinician will NOT set a rate, tidal volume, flow or target pressure. Instead, the clinician will simply set the percentage of work that the ventilator should do. f %Supp x x x x PAV+ V . V t P i
  36. 36. PAV+ Start patients at 70% and wean back to stabilize When disease process has sufficiently reversed, decrease %Support over 2 hr intervals
  37. 37. + PAV+ Potential Benefits 1. Comfort. 2. Lower peak airway pressure. 3. Less need for paralysis and/or sedation. 4. Less likelihood for over ventilation. 5. Preservation and enhancement of patient’s own control mechanisms such as metabolic ABG control and Hering-Breuer reflex. Some patients have a high rate normally, so a high rate on PAV + may or may not reflect distress; check other signs; Try increasing assist to see if rate goes down Don’t be surprised if RR climbs when switching from other modes
  38. 38. <ul><li>Circuit MUST be free of large leaks (small leaks are okay). </li></ul><ul><li>No external nebulizers which add flow. </li></ul>PAV+ Limitations PAV+ is NOT recommended for… <ul><li>Low Respiratory drive </li></ul><ul><li>Abnormal breathing pattern </li></ul><ul><li>Extreme air trapping </li></ul><ul><li>Large mechanical leaks. </li></ul>
  39. 39. APRV/BIPAP <ul><li>Maintain high FRC-better oxygenation </li></ul><ul><li>Lung in safe zone-less de-recruitment /VILI </li></ul><ul><li>Spontaneous breaths- diaphragm is active hence less VIDD/better Hemodynamics </li></ul><ul><li>Less sedation and analgesia? Conflicting results </li></ul><ul><li>APRV is IRV hence more impetus on Oxygenation/ synchrony problems persist </li></ul><ul><li>BIPAP- less synchrony problems </li></ul>Keeps the lung in lung protective zone Keeps the lung in lung protective zone
  40. 40. APRV settings P aw T high (4-5) Sec T low P high P low ( 1 sec) Time-triggered, Time-cycled, Pressure-limited, Spontaneous breathing is allowed at any point during the ventilatory cycle FLOW P high -This parameter is set with the goal of improving oxygenation. P low -The setting of this parameter has the goal of facilitating ventilation or CO2 clearance. It is this inverse inspiratory:expiratory (I:E) ratio that distinguishes APRV from bi-level positive airway pressure (BiPAP=1:1)
  41. 41. BiLevel Ventilation: <ul><li>Uses 2 pressure levels for 2 time periods </li></ul><ul><li>PEEP low & PEEP high , T high and T low </li></ul><ul><li>Patient triggering & cycling can change phases </li></ul><ul><li>If PS is set higher than PEEP H , the PS pressure is applied to a spontaneous effort at upper pressure </li></ul>If set PS < than Phigh then only applied in the lower pressure level If PS> than P-High,Then spontaneous breaths at both levels will be supported by PS P T Synchronized Transitions PEEP HIGH PEEP LOW T LOW T HIGH Synchronized Transitions PEEP High + PS P PEEP L PEEP H Pressure Support Spontaneous Breaths P Pressure Support T
  42. 42. Smartcare/NeoGanesh <ul><li>Complete Closed Loop </li></ul>
  43. 43. The “Zone of Respiratory Comfort” or “ZoRC” <ul><li>The 3 monitored parameters: </li></ul><ul><li>• spontaneous breath rate, fspn </li></ul><ul><li>• spontaneous tidal volume, VT </li></ul><ul><li>• etCO2 </li></ul><ul><li>“ ZoRC”-Goals: </li></ul><ul><li>Regulate Pressure Support to stabilize the patient within their ZoRC </li></ul><ul><li>2) Reduce PS stepwise ( in steps of 2 to 4 cmsH2o ) to no support, keeping the patient within their ZoRC. </li></ul><ul><li>3) Conduct a Spontaneous Breathing Trial with no support; if patient remains within ZoRC, recommend separation from ventilator. </li></ul>
  44. 44. Smartcare These therapeutic measures are based on a clinical protocol that has been tested and verified during several years of development ..
  45. 45. SmartCare/PS the clinical evidence <ul><li>In February 2008, the FDA gave clearance for additional claims of efficacy SmartCare can </li></ul><ul><li>Reduce overall ventilation time by 33% </li></ul><ul><li>Decrease ICU length of stay by up to 20% </li></ul><ul><li>Reduce weaning duration by up to 40% </li></ul>
  46. 46. New Modes of Mechanical Ventilation: Summary <ul><li>Older modes & ventilators: </li></ul><ul><ul><li>passive, operator-dependant tools </li></ul></ul><ul><li>New modes on new generation ventilators: </li></ul><ul><ul><li>adaptively interactive to patient </li></ul></ul><ul><ul><li>goal oriented </li></ul></ul><ul><ul><li>Low operator activity </li></ul></ul><ul><ul><ul><ul><li>Adapted from John J. Marini, MD; AARC congress, 11/98 </li></ul></ul></ul></ul>
  47. 47. The Evidence for New Ventilator Modes … <ul><li>It’s not the ventilator mode that makes a difference … </li></ul><ul><li>… It’s the skills of the clinician that makes the difference. </li></ul><ul><li>Any ventilator mode has the potential to do harm! </li></ul><ul><li>High level evidence is lacking that any new ventilator </li></ul><ul><li>mode improves patient outcomes compared to existing </li></ul><ul><li>lung-protective ventilation strategies. </li></ul>Dean Hess
  48. 48. Thank you Innovation and Automation is the future
  49. 50. PAV+ 80% with varying Demand Patient Work Machine Work
  50. 51. Amplification of Patient Effort <ul><li>• Small at low levels and high at high levels </li></ul><ul><li>• 20% Support-1.25:1 </li></ul><ul><li>• 50% Support -2:1ratio </li></ul><ul><li>• 95% Support 20:1 </li></ul>
  51. 52. Equation of Motion for the respiratory system <ul><li>Paw + Pmus = V’ x R +  V x E </li></ul>Ventilator output : Triggering, Cycling Control of flow, rise time and pressure Mechanical Patient response Chemical Reflex Behavioral
  52. 53. What is ASV? <ul><ul><ul><ul><li>Goal 2: Three-knob ventilation </li></ul></ul></ul></ul>T p Rate P sup P insp T i T e @ V t Conventional ASV FiO 2 PEEP CMV SIMV PCV PSV
  53. 54. How do I apply ASV? <ul><ul><li>Ideal Body Weight </li></ul></ul>Ideal Body Weight You <ul><ul><li>% Minute Volume </li></ul></ul>
  54. 55. How do I apply ASV? <ul><ul><li>Ideal Body Weight </li></ul></ul>Test breaths You <ul><ul><li>% Minute Volume </li></ul></ul>Automatically applies 3 test breaths to determine lung characteristics
  55. 56. ASV