6 ML/KG Tidal Volume Ventilation Strategy Synopsis

INITIAL VENTILATOR TIDAL VOLUME AND RATE ADJUSTMENTS

1. Calculate predicted body weight (PBW)
   • Male= 50 + 2.3 [height (inches) - 60] or 50 + 0.91 [height (cm) - 152.4]
   • Female= 45.5 + 2.3 [height (inches) - 60] or 45.5 + 0.91 [height (cm) - 152.4]
2. Mode: Volume Assist-Control
   1. Set initial tidal volume to 8 ml/kg PBW
   2. Reduce tidal volume to 7 ml/kg after 1-2 hours and then to 6 ml/kg PBW after 1-2 hours
   3. Set initial ventilator rate to maintain baseline minute ventilation (not > 35 bpm)

SUBSEQUENT TIDAL VOLUME ADJUSTMENTS

Plateau Pressure Goal: ≤ 30 cmH₂O

Check inspiratory plateau pressure (Pplat) with 0.5 second inspiratory pause at least every four hours and after each change in PEEP or tidal volume.

• If Pplat > 30 cmH₂O, decrease tidal volume by 1 ml/kg PBW steps to 5 or if necessary to 4 ml/kg PBW.
• If Pplat < 25 cmH₂O and tidal volume < 6 ml/kg, increase tidal volume by 1 ml/kg PBW until Pplat > 25 cmH₂O or tidal volume = 6 ml/kg.
• If breath stacking or severe dyspnea occurs, tidal volume may be increased (not required) to 7 or 8 ml/kg PBW if Pplat remains ≤ 30 cmH₂O.

ARTERIAL OXYGENATION

GOAL: PaO₂ 55-80 mm Hg or SpO₂ 88-95%

Use these FiO₂/PEEP combinations to achieve oxygenation goal.

RESPIRATORY RATE (RR) AND ARTERIAL pH
ARTERIAL pH GOAL: 7.30-7.45

1. Acidosis Management:
   • If pH 7.15-7.30:
     • Increase set RR until pH > 7.30 or PaCO₂ < 25 (Maximum Set RR =35)
     • If set RR = 35 and pH < 7.30, NaHCO₃ may be given (not required)
   • If pH < 7.15:
     • Increase set RR to 35.
     • If set RR = 35 and pH < 7.15 and NaHCO₃ has been considered, tidal volume may be increased in 1 ml/kg PBW steps until pH > 7.15 (Pplat target may be exceeded).
2. Alkalosis Management: (pH > 7.45):
   • Decrease set RR until patient RR > set RR.
     
     Minimum set RR = 6/min.
3. I:E RATIO
   
   GOAL: 1:1.0 - 1:3.0
   • Adjust flow rate and inspiratory flow wave-form to achieve goal.
4. WEANING:
   1. Conduct A CPAP trial daily when:
      1. FiO₂ ≤ 0.40 and PEEP ≤ 8, and
      2. PEEP and FiO₂ ≤ values of previous day, and
      3. Patient has spontaneous breathing efforts (may decrease vent set rate by 50% for 5 minutes to detect effort), and
      4. Systolic BP ≥ 90 mm Hg without vasopressor support.
      Conducting the CPAP Trial:
      1. Set: CPAP = 5 cmH₂O, FiO₂ = 0.50.
      2. If patient RR ≤ 35 for 5 min., advance to Pressure Support Weaning (See below)
      3. If patient RR > 35, return to previous A/C settings and reassess for weaning next morning.
   2. Pressure Support (PS) Weaning Procedure
      1. Set PEEP = 5 and FiO₂ = 0.50
      2. Set initial PS based on RR during CPAP trial:
         1. If CPAP RR < 25: set PS = 5 cmH₂O and go to REDUCING PS steps 3.3 to 3.4
         2. If CPAP RR = 25-35: set PS = 20 cmH₂O, then reduce by 5 cmH₂O at ≤ 5 min. intervals until patient RR = 26-35, then go to REDUCING PS step 3.1
         3. If initial PS not tolerated: return to previous A/C settings.
   3. REDUCING PS: (No reductions made after 1700 hrs)
      1. Reduce PS by 5 cmH₂O q 1-3 hr.
      2. If PS ≥ 10 cmH₂O not tolerated, return to previous A/C settings (If Weaning Tolerance Criteria O.K., resume last tolerated PS level next morning and go to step 3.1).
      3. If PS = 5 cmH₂O not tolerated, go to PS = 10 cmH₂O. If tolerated, PS of 5 or 10 cmH₂O may be used overnight with further attempts at weaning the next morning.
      4. If PS = 5 cmH₂O tolerated for ≥ 2 hours, assess for ability to sustain unassisted breathing (See below).
   4. UNASSISTED BREATHING TRIAL
      1. Place on T-piece, trach collar, or CPAP < 5 cmH₂O
      2. Assess for tolerance as below for two hours.
      3. If tolerated, consider extubation.
      4. If not tolerated, resume PS 5 cmH₂O.