5 farmer -mechanical_ventilation_workshop
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This document provides an overview of basic mechanical ventilation principles and techniques. It discusses establishing harm-free goals, synchronization between patient demand and ventilator delivery, avoiding lung injury through proper pressure and volume settings, identifying the target lung zone, modes of ventilation including CPAP, SIMV, APRV, and disorders related to flow such as starvation, excess flow, outflow obstruction, and inflow obstruction. Key conclusions are to understand ventilator waveforms, synchronize the ventilator to the patient, analyze problems, and use sedation judiciously.
5 farmer -mechanical_ventilation_workshop
- 2. “Play by the Rules”
- 3. Basic Principles: Establish Harm-Free Goals 1. SaO2 85-90% with certain exceptions 2. Follow pH not PaCO2 3. VT: ARDS versus other lung conditions 4. Paw: ARDS versus other lung conditions 5. Avoid drugs that may prolong weaning (sedatives, neuromuscular blockers) Better is the enemy of good…
- 4. Basic Principles: Establish Synchronization PATIENT DEMAND VENTILATOR DELIVERY • FLOW • PRESSURE • VOLUME
- 5. Basic Principles: Avoid Lung Injury • PRESSURE • VOLUME COLLAPSE RECRUITMENT ALVEOLAR SHEAR
- 6. Basic Principles: The Target Zone
- 7. Basic Principles: Lung immobilization = healing
- 8. patient Diaphragm }Pres PAlv P Pleura ventilator P Airway Airway pressure Flow Time Ti Te Stroetz et al. Basic Principles: Coordination of Purpose
- 9. Basic Principles: Know the Modes CPAP
- 10. Basic Principles: Know the Modes SIMV
- 11. Basic Principles: Know the Modes SIMV + PRESSURE SUPPORT SIMV
- 12. Basic Principles: Know the Modes ASSIST CONTROL (CMV)
- 13. Basic Principles: Know the Modes CMV versus PC
- 14. Basic Principles: Know the Modes APRV I E
- 15. Basic Principles: Know the Waveforms
- 16. Basic Principles: Know the Waveforms What is the flow pattern?
- 17. Basic Principles: Know the Waveforms Is this a pressure supported or SIMV or VAC breath?
- 18. Basic Principles: Know the Waveforms Is this pressure support or pressure control?
- 19. Basic Principles: Know the Waveforms X INADEQUATE INSP. FLOW Is the patient/ventilator synchronizing with the patient/ventilator?
- 20. Basic Principles: Know the Waveforms Inspiratory effort: patient work with pressure versus flow triggering VENTILATOR PATIENT VENTILATOR TUBING CIRCUIT LENGTH
- 22. Disorders of flow Flow starvation Excess flow Outflow obstruction Inflow obstruction
- 23. Flow Starvation
- 24. CMV, Volume Cycled Inspiratory Flow Starvation High respiratory drive Pain Fever Anxiety High inspiratory flow demand Patient outstripping the pre-set (fixed) ventilator flow rate Scalping of pressure waveform
- 25. Adjust Peak Flow to Meet Patient Inspiratory Demand
- 26. Excess flow INSPIRATORY FLOW RATE = 50 L/min LAMINAR INSPIRATORY FLOW RATE = 80 L/min TURBULENT
- 27. Excess Flow Inspiratory flow rate exceeds patient demand (flow rate) Rapid rise pressure tracing with “pressure overshoot” More is not better!
- 28. Air TrappingAir Trapping InspirationInspiration ExpirationExpiration NormalNormal PatientPatient Time (sec)Time (sec) Air TrappingAir Trapping AutoAuto--PEEPPEEP }} FlowFlow (L/min)(L/min) Outflow obstruction
- 29. A Auto - PEEP 10 cm H2O External PEEP 0 cm H2O B Auto - PEEP 10 cm H2O External PEEP 8 cm H2O C Net PEEP 12 cm H2O External PEEP 12 cm H2O Tobin MJ. Chest 1989; 96:449-451 Trigger Sensitivity and Auto- PEEP
- 30. Minimizing the Impact of Outflow Obstruction 1. Decrease rate (frequency) 2. Decrease VT 3. Increase inspiratory flow rate Volume vs Time ScalarVolume vs Time Scalar InspirationInspiration ExpirationExpiration Time (sec)Time (sec) VolumeVolume (ml)(ml) Inspiratory Tidal VolumeInspiratory Tidal Volume TTII
- 32. Increased Paw: Resistance versus Compliance Components of Inflation Pressure Components of Inflation Pressure Begin InspirationBegin Inspiration Begin ExpirationBegin Expiration 11 22 BBAA 1. PIP1. PIP 2.2. PPplatplat/Alveolar Pressure/Alveolar Pressure A. Airway ResistanceA. Airway Resistance B. Distending PressureB. Distending Pressure Time (sec)Time (sec) PPawaw (cm H(cm H22O)O)
- 33. Identifying the Cause of Inflow Obstruction “Kink” in the ET tube Secretions or mucous plugging Bronchospasm
- 34. Disorders of Pressure Reduced lung compliance Excess tidal volume (VT)
- 35. Reduced Lung Compliance Mainstem intubation Pneumothorax Pulmonary edema (alveolar flooding)
- 37. Excess VT: Paw Overdistension and Barotrauma
- 39. Patient Perceives “Insufficient” VT “DOUBLE TRIGGERING” MACHINE TI PATIENT TI T0 2ndbreathtriggered
- 40. Conclusions 1. Know the waveforms! 2. Synchronize the machine to the patient 3. “Seek” the cause of the problem by analysis techniques shown here today 4. Use sedation only after you have accomplished 1-3 (or in ARDS patients with VT