Initial mechanical ventilation settings

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Overview

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

Traditional

  • 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
  • Tidal volume: 5-8 cc/kg (eg. 500-600cc)
    • (adjust to plateau pressure <35 cmH20)
  • I/E 1:2
  • Pressure support: 5-8cm to overcome endotracheal tube

Lung Protective Strategy

Background

  • Focuses on low-tidal volume ventilation to reduce ventilator-associated lung injury (e.g. barotrauma and volutrauma worsening/causing ARDS)[1]
  • Based on ARDSnet trial with demonstrated mortality benefit
  • Indicated for all intubated patients who do not have obstructive lung disease (COPD, asthma)[2]

Settings[3]

  1. Mode
    • Volume-assist control
  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

Lung Protective FiO2 and PEEP Scale[4]

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

  • For patients with active bronchoconstriction (e.g. COPD, asthma)
  • The best ventilatory strategy for these patients is to avoid intubation if possible; mechanical ventilation will often make the pulmonary situation worse, rather than better.[5]
  • Goal = adequate time for expiration
  • Frequently requires deep sedation and analgesia (first-line); may required paralysis (second-line)[6]

Settings

  1. Mode
    • Volume-assist control
  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
    • 60-80 L/minute
      • Some advocate for higher rates (e.g. 80-100 LPM) to allow more expiration time, however this will increase the peak pressures and has not shown to produce any clinically meaningful change in the expiration time[7][8]
  4. FiO2/PEEP
    • Titrate FiO2 to desired SpO2
    • Set PEEP 0-5
  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[9]
        • If >30 go down on rate

Hypovolemic

  • Consider reducing PEEP to maintain adequate preload and prevent/minimize hypotension

Miscellaneous

Normally already set

  • Inspiratory flow rate = 60L/min[10] (100 L/min with asthma)
  • Sensitivity = 1-2 cmH2O

See Also

Mechanical Ventilation Pages

References

  1. Weingart SD. Managing Initial Mechanical Ventilation in the Emergency Department. Ann Emerg Med. 2016;68:614-617
  2. Weingart SD. Managing Initial Mechanical Ventilation in the Emergency Department. Ann Emerg Med. 2016;68:614-617
  3. 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.
  4. 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.
  5. Weingart SD. Managing Initial Mechanical Ventilation in the Emergency Department. Ann Emerg Med. 2016;68:614-617
  6. Weingart SD. Managing Initial Mechanical Ventilation in the Emergency Department. Ann Emerg Med. 2016;68:614-617
  7. Weingart SD. Managing Initial Mechanical Ventilation in the Emergency Department. Ann Emerg Med. 2016;68:614-617
  8. Leatherman JW, McArthur C, Shapiro RS. Effect of prolongation of expiratory time on dynamic hyperinflation in mechanically ventilated patients with severe asthma. Crit Care Med. 2004;32:1542-1545.
  9. 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.
  10. Weingart SD. Managing Initial Mechanical Ventilation in the Emergency Department. Ann Emerg Med. 2016;68:614-617