Mechanical ventilation workshop

Mechanical Ventilation Workshop J Christopher Farmer “Play by the Rules” Basic Principles: Establish Harm-Free Goals SaO2 85-90% with certain exceptions Follow pH not PaCO2 VT: ARDS versus other lung conditions Paw: ARDS versus other lung conditions Avoid drugs that may prolong weaning (sedatives, neuromuscular blockers) Better is the enemy of good… Basic Principles: Establish Synchronization VENTILATOR DELIVERY • • • FLOW PRESSURE VOLUME PATIENT DEMAND Basic Principles: Avoid Lung Injury ALVEOLAR SHEAR • PRESSURE • VOLUME COLLAPSE  RECRUITMENT Basic Principles: The Target Zone Basic Principles: Lung immobilization = healing Basic Principles: Coordination of Purpose patient }P res P Airway P PAlv Pleura ventilator Diaphragm Airway pressure Flow Ti Stroetz et al Te Time Basic Principles: Know the Modes CPAP Basic Principles: Know the Modes SIMV Excess flow LAMINAR TURBULENT INSPIRATORY FLOW RATE = 50 L/min INSPIRATORY FLOW RATE = 80 L/min Excess Flow Inspiratory flow rate exceeds patient demand (flow rate)  Rapid rise pressure tracing with “pressure overshoot”  More is not better!  Outflow obstruction Trigger Sensitivity and AutoPEEP A Auto - PEEP 10 cm H2O External PEEP cm H2O B Auto - PEEP 10 cm H2O External PEEP cm H2O C Net PEEP 12 cm H2O External PEEP 12 cm H2O Tobin MJ Chest 1989; 96:449-451 Minimizing the Impact of Outflow Obstruction Decrease rate (frequency) Decrease VT Increase rate inspiratory flow Inflow Obstruction RESISTANCE Increased Paw: Resistance versus Compliance Identifying the Cause of Inflow Obstruction  “Kink” in the ET tube  Secretions or mucous plugging  Bronchospasm Disorders of Pressure  Reduced lung compliance  Excess tidal volume (VT) Reduced Lung Compliance  Mainstem intubation  Pneumothorax  Pulmonary edema (alveolar flooding) Peak versus Plateau Pressure Excess VT: ↑ Paw Overdistension and Barotrauma Inappropriate I-Time (Dyssynchrony) Patient Perceives “Insufficient” VT MACHINE TI PATIENT TI “DOUBLE TRIGGERING” 2nd breath triggered T0 Conclusions Know the waveforms! Synchronize the machine to the patient “Seek” the cause of the problem by analysis techniques shown here today Use sedation only after you have accomplished 1-3 (or in ARDS patients with  VT