Ventilation settings

Initial

  • FiO2 100% (1.0) and ween down
  • Rate 8-12/min
    • consider 5-6 for asthma with permissive hypercapnea
  • Mode
    • A/C = default (most)
    • SIMV = with obstructive airway disease and an intact respiratory effort (e.g. some COPD, asthma)
    • PC = with intact respiratory effort and non-severe respiratory failure (prefered in chronic vent)
  • PEEP 0-5 mmH20
  • TV 5-8 cc/kg (eg. 500-600cc)
    • (adjust to plateau pressure <35 cmH20)
  • I/E 1:2
  • PS (pressure support) 5-8cm to overcome endotracheal tube

Initial ventilation settings

Disease TV (cc/kg) Respiratory Rate I:E PEEP FiO2
Normal lung 8 10-12 1:2 5 100%
Bronchoconstriction 6 5-8 1:4 5 100%
ARDS 6 12-20 1:2 2-15 100%
Hypovolemic 8 10-12 1:2 0-5 100%

Lung Injury Strategy

Background

  • Ok for all patients except for obstructed

Settings

These settings are based on a lung protective strategy[1]

  1. Mode
    • Assist control Volume
  2. Tidal Volume (lung protection)
    • Start 6-8cc/kg predicted body wt
      • Predicted body weight is used because a persons lung parenchyma does not increase in size as the person gains more weight.
    • Titrate down if peak pressure >30 mmHg
  3. Inspiratory Flow Rate (comfort)
    • More comfortable if higher rather than lower
    • Start at 60-80 LPM
  4. Respiratory Rate (titrate for ventilation)
    • Avg patient on ventilator requires 120mL/kg/min for eucapnia
    • Start 16-18 breaths/min
    • Maintain pH = 7.30-7.45
  5. FiO2/PEEP (titrate for oxygenation)
    • Move in tandem to achieve:
    • SpO2 BETWEEN 88-95%
    • PaO2 BETWEEN 55-80
FiO2 0.3 0.4 0.4 0.5 0.5 0.6 0.7 0.7 0.7 0.8 0.9 0.9 0.9 1.0 1.0 1.0
PEEP 5 5 8 8 10 10 10 12 14 14 14 16 18 20 22 24

Obstruction Strategy

Background

Goal = Adequate time for expiration

Settings

  1. Mode
    • Assist Control Volume
  2. Tidal Volume
    • Vt = 6-8 cc/kg of Ideal Body Weight
      • Ideal Body Weight used because lung parenchyma does not increase in size as the person gains more weight
  3. Inspiratory Flow Rate
    • Set at 80-100 LPM to allow more expiration time
  4. FiO2/PEEP
    • Titrate FiO2 to desired SpO2
    • Set PEEP 0-4
  5. Respiratory Rate
    • Set low - 10 BPM
    • Adjust for I:E 1:4 or 1:5
    • Permissive hypercapnia to avoid breath stacking
      • Ok as long as pH > 7.00-7.10
      • Maintain plateau pressure <30[2]
        • If >30 go down on rate

Making Setting Changes

O2

  • PaO2 - ween O2 for a goal PaO2 >60 mmHg)
  • FiO2 - ween to < 50% if possible while maintaining adequate PaO2
  • PEEP - refer to ARDsnet protocol to avoid barotrauma

paCO2

  • Mainly affected by Tidal volume and RR
  • VE = minute ventilation (RR x TV)

pH

  • For every increase or decrease in PaCO2, pH changes accordingly by 0.008
  • For every increase or decrease in HCO3 pH changes accordingly by 0.015

MISC (normally already set)

  • Inspiratory flow rate = 60L/min (100L/min with asthma)
  • Sensitivity = 1-2 cmH2O

See Also

Mechanical Ventilation Pages

References

  1. The Acute Respiratory Distress Syndrome Network. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. The Acute Respiratory Distress Syndrome Network. N Engl J Med. 2000;342(18):1301-1308.
  2. 20. Oddo M, Feihl F, Schaller MD, Perret C. Management of mechanical ventilation in acute severe asthma: practical aspects. Intensive Care Med. 2006; 32(4):501-510.