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Ventilator Strategies

Bryan Winchell
March 31, 2013
72

Ventilator Strategies

Lung protective and obstructive vent strategies for the critical care transport environment.

Bryan Winchell

March 31, 2013
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Transcript

  1. FFL Approach —  Use ABG to guide therapy, correlate with

    EtCO2 —  Bundle: HOB 30-deg, cuffed ETTs, volume based on IBW, —  Just two strategies of ventilation 1.  Lung Protective 2.  Obstructive
  2. Ventilation is all about CO2, and is corrected with minute

    volume (RR x tidal volume) Oxygenation is all about O2, and is corrected with mean airway pressure (FiO2 and PEEP)
  3. 2 subsequent meta-analyses 10 randomized studies Lower tidal volume strategies

    confirmed repeatedly Save one life every 11 patients by using lower tidal volumes +
  4. The good —  Improves V/Q match —  Decreases shunt — 

    Decreases atelectasis/recruits alveoli —  Supports and increases FRC —  Keeps terminal bronchioles open to prevent air trapping PEEP
  5. Airway and Alveolar Pressures High airway pressures by themselves are

    not particularly harmful, unless it reflects high alveolar pressures —  Airway pressure = (flow x resistance) + (alveolar pressure) Detrimental effects of high alveolar pressures, that are incorrectly associated with high airway pressures: —  Barotrauma may result in acute lung injury (leading to ARDS) —  May cause pneumothorax, pneumomediastinum —  Excessive intrathoracic pressure causes hypotension
  6. How do we estimate alveolar pressures? —  Inspiratory hold maneuver

    —  Flow is reduced to zero and airway/alveolar pressures equalize
  7. Why do airway pressures matter then? —  High airway pressures

    (PIP) may result in inadequate ventilation. —  Gives us an indication of airway resistance (bronchospasm) Airway pressure = (flow x resistance) + (alveolar pressure) —  PIP <30 means alveolar pressure <30 —  Can decrease flow by slowing RR or extending I-time
  8. The P/F Ratio —  PaO2 divided by FiO2 —  100

    mmHg / 0.5 = 200 —  80 mmHg / 0.21 = 381 —  P/F Ratio <300 = ALI (Acute Lung Injury) —  P/F Ratio <200 = ARDS scorecard of oxygenation:
  9. Obstructive Strategy Summary —  Consider compensating for autoPEEP —  If

    sudden hypotension, disconnect circuit and allow exhale —  Sedate! Permissive hypocapnea is painful
  10. If your patient is Crashing: —  Take the ventilator out

    of the equation: bag the patient to feel compliance first-hand —  Check the tube: displaced, obstructed, deflated —  Check the patient: pleural slide via ultrasound, needle decompression —  Check the ventilator —  If obstructive: disconnect circuit and allow patient to exhale. Use fluids to increase preload.