Mechanical Ventilation for Dummies - Denver, Colorado

1 Mechanical Ventilation for Dummies Keep It Simple Stupid Indications airway obstruction airway Inability to protect Ventilation failure airway (CO2). Hypoxia (PaO2 < 50). Hypoxia Combination Hypercapnia (PaCO2. > 50). Respiratory distress (RR > 30, use of accessory muscles). Ventilator Management Scalar CMV Control Mode- Scalars ACV (Volume- (Volume- Targeted Targeted Ventilation ). Ventilation ). IMV. Preset Preset Peak Peak Flow Flow FF lloo ww SIMV (L/min). (L/min). SIMV + PS. PCV Dependent Dependent on C. on PP rree ss ss uu rree CLL &. & RRaw aw (cm H O). (cm H22O). IRV. PRVC Preset Preset V. Vtt VVVV oooollluluuummmmeeee (ml). APRV (ml). Essentials Essentials of of Ventilator Ventilator Graphics TT iimm ee (s (s ee cc )) . 2000. 2000 RespiMedu CPAP Graphics RespiMedu CLINICAL UTILITY OF VENTILATOR GRAPHICS.

2 Vijay Deshpande, MS, RRT, FAARC. Ventilator Management Loops pressure -Volume pressure -Volume Loops Flow-Volume Flow-Volume Loop Loop VVTT. Inspiration Inspiration nn 11. tiioo Flow Flow raat piir (L/min). (L/min). EExxp Volume Volume ((mL). 44 33. mL)). mL. mL). nn Volume Volume (ml). ttiioo (ml). irraa FRC. FRC. sppi IInns PPaw (cm H O) PIP. PIP 22. aw (cm H22O). Expiration Expiration Essentials 2000 RespiMedu . Essentialsof of Ventilator Ventilator Graphics Graphics 2000 RespiMedu Essentials Essentials of ofVentilator Ventilator Graphics Graphics 2000. 2000 RespiMedu RespiMedu CLINICAL UTILITY OF VENTILATOR GRAPHICS. Vijay Deshpande, MS, RRT, FAARC. Ventilator Management This really is all there is to it Time (RR). Volume (Vt). pressure (PIP, Pplat).

3 Flow Volume Volume vs vs Time Time Scalar Scalar Inspiratory Inspiratory Tidal Tidal Volume Volume Volume Volume Inspiration Inspiration (ml). (ml) Expiration Expiration TI. TI. Time Time (sec). (sec). Ventilator Management Control Mechanical Ventilation Time Set respiratory rate .. Volume Set Vt Flow Set to deliver the Vt } Independent Variables airway pressure Dependent on the interaction of the above and on the respiratory system compliance and airflow resistance Ventilator Management pressure Control Ventilation Time Set respiratory rate .. pressure Set pressure Flow Set to deliver pressure } Independent Variables Volume Dependent on the interaction of the above and on the respiratory system compliance and airflow resistance Ventilator Management Dual Control Modes - PRVC.

4 Time Set RR.. Volume Set VT. Flow Set } Independent Variables pressure increases or decreases to maintain the set VT (Dependent variable), but this is Limited ( controlled). airway pressure release Ventilation APRV-BILEVEL Advantages 1. Lower Paw for a given VT. 2. Lower VE, , less dead SIMV space 3. Limited adverse effects on cardiac function 4. Spontaneous breathing 5. Decreased sedation Potential Disadvantages 1. Volumes change with changes in compliance and resistance 2. New technology CPAP is transiently decreased or 3. Limited access to technology released to a lower level during 4. Limited research and clinical expiration. experience Ventilator Management Peak Insp pressure (PIP) vs. Plateau airway Components of Inflation pressure (P plat) pressure Transairway pressure 1.

5 1. PIP. PIP. 2. P. 2. Pplat /Alveolar pressure plat/Alveolar pressure 11. PIP-Pplat A. A. airway Resistance B. airway B. Distending Resistance Distending pressure pressure 22. Obstruction PPaw aw (cm (cm HH22O) A. A. Secretions O) BB. RAD Time Time (sec). (sec). Begin Begin Inspiration Inspiration Begin Begin Expiration Expiration CLINICAL UTILITY OF VENTILATOR GRAPHICS. Vijay Deshpande, MS, RRT, FAARC. Ventilator Management Compliance Relationship of volume to pressure Lung Lung Compliance Changes Changes in in the P-V. P-V Loop Loop Dynamic vs static Volume Volume Targeted Targeted Ventilation Ventilation VVTT. COMPLIANCE. COMPLIANCE. COMPLIANCE. COMPLIANCE. Normal Normal Volume Volume (mL. (mL). ((mL)). mL) Increased Increased Decreased Decreased PIP.

6 PIP levels levels PPaw (cm H O). aw (cm H22O). Essentials Essentials of of Ventilator Ventilator Graphics Graphics 2000.. 2000 RespiMedu RespiMedu CLINICAL UTILITY OF VENTILATOR GRAPHICS. Vijay Deshpande, MS, RRT, FAARC. History of Mechanical Ventilation Poliomyelitis Negative pressure (iron lung). WW II. Positive pressure cycled (Bennett and Bird). Volume cycle (Emerson). VT 6-8 ml/kg, Sigh 12-18 ml/kg VT 10-15ml/kg without sighs ARDS & PEEP. Ashbaugh Bigelow and Petty UCHSC 1967. Ventilator Induced Lung Injury VILI is due to volume (Overdistension). Ventilation 45 cm H2O. Baseline 5 min 20 min Dreyfuss Am. Rev. Respir. Dis. 1998; 137: 1159-1164. ARDS is Not Homogeneous Gattinoni L. Milan Italy Inflection Points Paw increases with little change in the volume Lower Upper Lung Lung Compliance Compliance Changes Changes Overdistension Overdistension in in the the P-V.

7 P-V Loop Loop PPaw rises with little or no change in V. Volume VolumeTargeted Targeted Ventilation Ventilation aw rises with little or no change in VTT. VVTT. COMPLIANCE. COMPLIANCE. COMPLIANCE. COMPLIANCE. Normal PPaw Normal Normal Normal aw Volume Volume(mL. (mL). ((mL)) (cm (cm HH22O). O). mL) Increased Increased Increased Increased Decreased Decreased Decreased Decreased pressure pressure (cm (cm HH22O). O). PIP. PIP levels levels PPaw (cm H O). Essentials Essentialsof ofVentilator VentilatorGraphics Graphics aw (cm H22O) 2000 RespiMedu 2000 RespiMedu Essentials Essentialsof ofVentilator VentilatorGraphics Graphics . 2000. 2000 RespiMedu RespiMedu CLINICAL UTILITY OF VENTILATOR GRAPHICS. Vijay Deshpande, MS, RRT, FAARC. ARDSnet NIH NHLBI ARDS Clinical Trials Network ARDS Network: ARMA.

8 Respiratory Management in ARDS. 6 vs. 12 ml/kg Tidal Volume Mode: Volume Assist / Control Rate: Set rate < 35; adjust for pH goal = Oxygenation PaO2 = 55-80 mmHg SaO2 = 88-95%. PEEP 5 5 8 8 10 10 10 .. 20. FiO2 .3 .4 .4 .5 .5 .6 .7 .. I:E = 1 Weaning by pressure Support when PEEP/FiO2 < 8/.40. New Eng J Med 2000; 342: 1301. ARDS Network: ARMA. Respiratory Management in ARDS. 6 vs. 12 ml/kg Tidal Volume 12 ml/kg Group 6 ml/kg Group Initial Vt = 12 ml/kg IBW Initial Vt = 6 ml/kg IBW. If Pplat > 50 cmH20, If Pplat > 30 cmH20, reduce Vt by 1 ml/kg. reduce Vt by 1 ml/kg. Minimum Vt = 4 ml/kg Minimum Vt = 4 ml/kg. If Pplat < 45 cmH20 and If Pplat < 25 cmH20 and Vt < 11 ml/kg, increase Vt Vt < 5 ml/kg, increase Vt by 1 ml/kg. by 1 ml/kg. New Eng J Med 2000; 342: 1301.

9 ARDS Network: ARMA. Respiratory Management in ARDS. 6 vs. 12 ml/kg Tidal Volume 45 Plateau pressure 6 ml/kg 40 12 ml/kg * * * *. cm water 35. 30 33 + 8. 25. 25 + 6. 20. 0 1 2 3 4. Study Day New Eng J Med 2000; 342: 1301. ARDS Network: ARMA. Respiratory Management in ARDS. 6 vs. 12 ml/kg Tidal Volume 6 ml/kg 200. 10. * * 12 ml/kg 8. 180. * * * 6. PEEP. P/F 160 (cm water). 4. 140 6 ml/kg 12 ml/kg 2. 120 0. 0 1 2 3 4 0 1 2 3 4 7 14 21. Study Day Study Day New Eng J Med 2000; 342: 1301. ARDS Network: ARMA. Respiratory Management in ARDS. 6 vs. 12 ml/kg Tidal Volume Vt 6 vs. 12 ml/kg Mortality vs New Eng J Med 2000; 342: 1301. ARDS Network: ALVEOLI. High vs. Low PEEP. Ventilator management the same as ARMA. except PEEP. Lower PEEP/ Higher FiO2 Treatment Group FiO2 30 40 40 50 50 60 70 70 70 80 90 90 90 100.

10 PEEP 5 5 8 8 10 10 10 12 14 14 14 16 18 18-24. Higher - PEEP/Lower FiO2 Treatment Group FiO2 30 30 30 30 30 40 40 50 50 50-80 80 90 100 100. PEEP 5 8 10 12 14 14 16 16 18 20 22 22 22 24. N Engl J Med 351:327, July 22, 2004. ARDS Network: ALVEOLI. High vs. Low PEEP. Variable Day 1 Day 3 Day 7. Low High Low High Low High PEEP P/F 168 220 169 206 181 218. N Engl J Med 351:327, July 22, 2004. ARDS Network: ALVEOLI. High vs. Low PEEP. Conclusions VT goal 6 ml/kg Pplat limit of 30 cm H2O, Outcomes are similar whether lower or higher PEEP levels are used. N Engl J Med 351:327, July 22, 2004. ARDS Network: FACTT. Fluids and Catheter Treatment Trial PAC vs. CVP. N Engl J Med 354:2213, May 25, 2006. ARDS Network: FACTT. Conservative vs. Liberal Fluid N Engl J Med 354:2564, June 15, 2006.