Initial mechanical ventilation settings

Revision as of 15:34, 12 December 2015 by Ostermayer (talk | contribs) (O2)

Initial

  • FiO2 100% (1.0) and ween down
  • Rate 8-12/min
    • consider 5-6 for asthma w/ 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 Tidal Volume (mL/kg^) Respiratory Rate I:E PEEP FiO2
Traditional 8 10-12 1:2 5 100%
Lung Protective (e.g. ARDS) 6 12-20 1:2 2-15 100%
Obstructive (e.g. bronchoconstriction) 6 5-8 1:4 0-5 100%
Hypovolemic 8 10-12 1:2 0-5 100%

^Ideal body weight

Lung Injury Strategy

Background

  • Ok for all pts 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 pt 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 = 8 cc/kg predicted body wt
  • 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 to O2 >90% and PaO2 >60 mmHg)
  • FiO2 - ween to < 50% if possisble while maintaining adequate PaO2
  • PEEP - refer to ARDsnet protocol to avoid barotrauma

CO2

  • PCO2
    • TV
    • Rate
  • (VE-1 x pCO2-1 = VE-2 x pCO2-2)
    • VE = minute ventilation (RR x TV)

pH

to increase pH 0.01 --> decrease pCO2 by 1

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.