1.Nonconventional Modes of Ventilation VIJAY DESHPANDE, MS, RRT, FAARC Emeritus ProfessorAdjunct Professor Georgia State UniversityManipal University Atlanta, GeorgiaManipal, Karnataka USA India Evolution of Mechanical Ventilation Resuscitation Bags Negative Pressure Ventilation ( Iron Lung etc.) Pressure Cycled Ventilators ( Bird, Bennett etc.) Volume Ventilators (Bennett MA-1, Bear 1, Emerson Post-op) SIMV Ventilators ( Siemens 900 C etc.) Third Generation Ventilators ( PB 7200, Hamilton Veolar, Bird 6400 etc.) Microprocessor Ventilators ( Siemens 300, Hamilton Galileo, Bird 8400 ST, Bear 1000 etc.)

2. Advancements in Mechanical VentilationControl, Assist, PEEP, CPAPVENTILATOR CLOSED-LOOPIMV, GRAPHICSVENTILATION SIMV,PSV,PCV,Combinations of Volume or PressureVAPS, Paug ventilation:Volume Support,SIMV +PSV, PRVC, Auto-flow, SIMV+PSV+CPAPASV,APV, VS, auto modePAV,NAVAHow is Closed Looping Accomplished ? I have absolutely no idea. 3. Flow SensorFlow Sensor Flow TriggeringCHURCH BULLETIN BLOOPERS A bean supper will be held on Tuesday evening in the church hall. Music will follow. 4. Decision MakingAfter initiating SIMV, within an hour the ABGsreturn to normal levels, however the patientdemonstrates use of accessory muscles andincreased work of breathing.Unsupported Breathing through a Tracheal Tube 5. SIMV + PS(Pressure-Targeted Ventilation)Time-CycledTime-Flow-CycledFlow (L/min)Set PC level Pressure Set PS level (cm H2O)Volume(ml)Time (sec)PS BreathAcute Lung Injury (ALI)ALI is described as: Acute onset of Hypoxemia with P/F ratio of = 300 mm Hg Bilateral infiltrates on a frontal Chest Radiogram Absence of Left Atrial Hypertension (Normal PCWP ) ALI with most severe hypoxemia with P/F ratio < / = 200 mmHg is termed as ARDS 6. ALI and ARDS Approximate incidence of 59 (ALI) and 29 (ARDS)cases per 100,000 persons/year Mortality ~ 34-58 % Economic burden on Uninsured, inadequately insuredpatients, Hospitals, Government and Insurance CompaniesLung Protective Ventilation NEJM 2000; 342 (18) : 1301-1308 Small V T and Low Airway Pressures is the onlyintervention found to reduce mortality from ALI/ARDS May promote progressive lung derecruitment and worseningof oxygenation 7. Recruitment Maneuver Recruitment refers to reopening collapsed lung units usingtransient increase in the transpulmonary pressure The rationale for recruitment maneuvers is to improvealveolar recruitment and increase end-expiratory volumein order to:a. Improved gas exchangeb. Reduced overdistension of relatively healthy lung unitsc. Prevent repetative opening and closing of unstable alveoli ARDSsAcute Respiratory Distress SyndromesPulmonary endothelial Inflammation leading to Acute Lung InjurysFurther deterioration promotes ARDS 8. ARDSs Inflammatory response promotes: increased pulmonary vascular permeability seepage of proteinaceous fluid into thepulmonary interstitium and alveoli reduction in Surfactant production andinactivation of existing Surfactant increased surface tension microatelectasis in the affected areas The American-European Consensus Conference on ARDS. Am J Respir Crit Care Med 1994; 149:818-824 9. Dilemma in Ventilatory Management of ARDS Objective: Reopen collapsed and recruitable alveoli Strategy: Application of Positive Pressure Ventilation Commonly used Mode of Ventilation: Volume Targeted Problem: Alveolar Overdistention 10. Oh! Sh*! Acute Lung Injury (( ALI )) and ARDS Acute Lung Injury ALI and ARDSDamage to the Lung : G Not distributed homogenously G Even in severe cases ~ 1/3 lung is open G Open lung receives the entire tidal volume resulting in :Over-distention Over-Local hyperventilationInhibition of surfactantsRavenscraft, Sue. Respiratory Care, Vol 41, No 2 : 105-111, Feb 105-1996 11. ARDSC o lla p s e dR e c r u ita b le N orm alARDS Volume Augmented Breath CollapsedRecruitable Normal 12. Over-distention Over-distentionPreset Tidal Volume With little or With little orno change in VTno change in VTNormal Volume (ml)AbnormalPawPaw Pressure (cm H2O) Over-distentionG Observed on a Pressure-Volume LoopPressure-G Indicates hyperinflation or excessive applicationof pressureG May promote BarotraumaG Corrective action includes reduction in the PeakInspiratory Pressure or Tidal Volume 13. CRITICAL THINKING 4Common sense for anexperienced therapist iscritical thinking for a novice. 4 Critical thinking at the bedside is synonymous with Differential diagnosis.What shouldI do Now? 14. PRESSURE TARGETED VENTILATIONd PIP and Palv are Limitedd Prevents Alveolar Over-distentiond Provides better Patient-Ventilatorsynchronyd Delivered Tidal Volume dependson Airway Resistance and LungComplianced PaCO2 is variableAssisted Mode (Pressure-Targeted Ventilation) (Pressure-TargetedPatient Triggered, Pressure Limited, Time Cycled VentilationTime-Cycled Flow (L/min) Set PC levelPress(cm H2O)ureVolume(ml)Time (sec) 15. ARDS Pressure Augmented Breath PPP Collapsed Recruitable NormalARDS network.N Eng J Med 2000, 342(18):1301-1308.Multi-center NIH study demonstrated thatALI/ARDS patients ventilated with tidalvolumes of 6 ml/Kg were significantly morelikely to survive than those ventilated withtidal volumes of 12 ml/Kg. 16. ARDSnet Findings G Lower Tidal Volumes G Use of rapid rates avoiding auto-PEEP (35/min ) G PPLAT30 cm H2O reduces mortality G Lower PPLAT showed better outcome ARDSnet: 6ml/kg reduces mortality vs. 12 ml/kg Components of Inflation Pressure PIPPaw (cm H2O) }Transairway Pressure (PTA)Exhalation Valve OpensPplateau Inspiratory Pause(Palveolar) Expiration Time (sec)Begin InspirationBegin Expiration 17. Strategies to Ventilate ALI and ARDS patientsG Prevent Alveolar Over-distention Use of low Tidal Volumes (5-7 ml/Kg) May promote de-recruitment of alveoliG Prevent repetitive alveolar opening and closure Use of Recruitment Maneuversustained increase in airway pressureapplication of adequate end-expiratory pressure(PEEP/CPAP)Possible Approaches to Ventilate ARDS Patients G APRV G PCIRV G BiLevel or BiVent G PRVC G HFO No data to indicate that any mode of ventilation is BETTER than conventional Pressure-A/C ventilation 18. CHURCH BULLETIN BLOOPERSAt the evening service tonight,the sermon topic will be What Is Hell?Come early and listen to our choir practiceHow much PEEP? 19. Amato MB., et al., Effect of a protective-ventilationstrategy on mortality in ARDS.N Eng J Med 1998;338(6):347-354Initial recruitment of alveolar units may beachieved by applying PEEP at a level abovethe lower inflection point of the P-V curve. 20. Lung Protective StrategyVolume (ml)PEEP2-3 cm H2O above LIPLower Inflexion Point ( Pflex)The lower inflection point (Pflex)is obtained by static inflationmaneuver and should not bemeasured from the dynamic curve. 21. Initial PEEP Level2-3 cm H2O above the Lower Inflection Point CHURCH BULLETIN BLOOPERSThe sermon this morning:Jesus Walks on the Water.The sermon tonight:Searching for Jesus. 22. Rationale for Closed Loop Ventilation Establish Homeostasis relatively faster Improve Quality of Care Improve Safety Address Resource LimitationsImprove Quality and SafetyEstimated deaths in US due to medical error range from44,000 to 98,000 per year Improper use of mechanical ventilation has shown to havedetrimental effectsICU patients frequently have multiple system illnesses andrequire multiple testing and bedside decision makings Closed-Loop ventilation can prevent improper settingMarc Wysocki and Josef Brunner ; Closed-Loop Ventilation in Critical Care ClinicsVol 23, No 2, 223-237, April 2007 23. Address Resource LimitationsMechanical Ventilation is generally a labor intensive taskOn an average daily cost of Mechanical Ventilation is $ 1,500Labor shortage or excessive work load per clinician is notuncommonClosed-Loop can provide care at lower labor costClosedLoop Ventilation can support clinicians with limitedability to incorporate data into decision makingMarc Wysocki and Josef Brunner ; Closed-Loop Ventilation in Critical Care ClinicsVol 23, No 2, 223-237, April 2007Some actions do not correct auto-PEEP 24. Closed-Loop Ventilation PRVC, VC+, VAPS, PCV-VGASVPAV, NAVAAdjust pressure to meet the Advanced Versionset Tidal Volumeof PSV Incorporates several modes PSV, PCV, P-SIMV to deliver Appropriate VE Closed-Loop VentilationGeneral Scheme:PaO2 or output SpO2 RESPIRATORY FiO2SYSTEM 25. Closed-Loop Ventilation Set P, V or flowRESPIRATORYComparatorVENTILATOR SYSTEM Measured Pressure, Volume and FlowGeneric Scheme 26. COMBINED PRESSURE/VOLUMEVENTILATIONG Exploit beneficial effects of bothPressure and Volume VentilationG Improve Patient-ventilator Synchrony Patient-G Prevent ventilator induced lung injury 27. CHURCH BULLETIN BLOOPERSThis evening at 7 PM there will be a hymnsing in the park across from the Church.Bring a blanket and come prepared to sin Closed-loop VentilationG Volume Support ( VS )G Pressure Regulated Volume Control ( PRVC )G Adaptive Support Ventilation ( ASV )G Proportional Assist Ventilation ( PAV )G Nuerally Adjusted Ventilator Assistance (NAVA) 28. Volume SupportPatient Trigger Servo Trial breath to calculate ComplianceiPressure limit is set = VT/ CBreath DeliveredExhaled VolumeFlow decreases to 5%measuredof peak flowPS level is adjusteduntil Exhaled VT=Set VT Termination of Inspiration In case of apnea, the mode switches to PRVCPRVC Servo iTrigger OnExhaled VTSet VTExhaled VTSet VTPressure Support level Pressure Support levelincreases stepwise decreases stepwise untiluntil Exhaled VT = Set VTExhaled VT = Set VTServo 300 Ventilator, Maquet Inc. 29. Pressure Regulated Volume Control (PRVC) Volume Control+ ( VC + ) AutoflowAdaptive Support Ventilation (ASV)Pressure Control Ventilation with VolumeGuarantee ( PCV VG) 30. AUTO- MODE Control Mode Support ModeDecrease Work of BreathingFacilitate Weaning Auto-ModeCoupling Modes to combine Control and SupportPressure Control Pressure SupportVolume Control Volume SupportPRVC Volume Support 31. Adaptive Support Ventilation (ASV)The ASV assures a pre-selected target ventilationUses sophisticated calculations based on set tidalvolume, rate, and the patients lung mechanicsThe clinician sets: Desired minute ventilation Maximum Airway Pressure Prevents rapid shallow breathing and avoidsvolutraumaThe patient is protected from apnea and AutoPEEP Source: Hamilton Medical Proportional Assist ventilation(PAV)!Strictly a patient triggered mode!The ventilator adjusts pressure in response to patient effort!The clinician sets: IPAP EPAP Flow Assist Level PB 840 Volume Assist Level 32. 0%100 %CHURCH BULLETIN BLOOPERSLow Self-esteem Support Group will meetThursday at 7 PM.Please use the back door. 33. NAVANeurally Adjusted Ventilatory Assist Servo iNeural Pathway to Cural DiaphragmNeural pathways to the crural diaphragm. 34. NAVATrigger delay from inspiration to the beginning offlow from ventilator ~ 100 msInsuflation during exhalation and the trigger delaypromotes asynchrony in COPD and patientsrequiring high PSVia Electrical activity of the Diaphragm (Edi)NAVA provides full synchrony with therespiratory effort made by the patient 35. Clinical Benefits of NAVAReduce Work of BreathingAppropriate ventilationVariations in the amplitude of Edi preventexcessively high or low ventilationAdaptation to changes in metabolicdemandsAvoidance of diaphragmatic atrophyReduced weaning timeShortened hospital stay 36. PATIENT Controlled Ventilation