Ventilator Setting for Obstructive Lung Disease

Author: Jenny Wilson, MD
Updated: 10/21/2011

Ventilator Setting for Obstructive Lung Disease

Goal in obstruction (asthma/COPD)

Give the patient time to exhale

Initial vent settings for patient with predicted Ideal Body Weight (IBW) = 70 kg (5'9" male; 5'11" female)

  • Mode = Volume Assist Control (AC)
  • Tidal volume = 560 mL
  • Inspiratory flow rate = 80 L/min
  • Respiratory rate = 10
  • FiO2 = 100%
  • PEEP = 0-5
  • Goal Pplt < 30 cmH2O

Ventilator Mode

Volume Assist Control (AC)

Tidal Volume (Vt)

8 mL/kg Based on ideal body weight (kg)

Inspiratory Flow Rate (IFR)

80-100 L/min

  • Increase IFR and ensure adequate sedation if patient uncomfortable or sucking on tube

Respiratory rate (RR)

Start at 10, then adjust to give time to exhale (IMPORTANT)

  • Goal I:E of 1:4 or 1:5
  • Permissive hypercapnea, as long as pH stays above 7.2
  • Prevents air-trapping/auto PEEP


Start at FiO2 100% and PEEP 0-5

  • Goal SpO2 = 92-95%
  • Can usually quickly titrate down the FiO2

Plateau Pressure (Pplt)

  • Goal Pplt <30 cm H2O
  • Check after initial settings and at regular intervals thereafter
  • Technique: Press inspiratory hold button for 0.5 sec and look at pressure gauge
  • If Pplt >30 cm H2O, investigate possible air trapping

Air-Trapping (Auto-PEEP)

  • Air trapping (auto-PEEP) = gas trapped in alveoli at end-expiration
  • Suspect auto-PEEP if P(plat) >30 cm H2O, or if hypotension develops
  • First step is to disconnect vent and allow trapped air to escape
  • Prevent further air trapping by decreasing RR and increasing expiratory time

Diagram of auto-PEEP ventilator flow waveform


  • EMCrit. Available at: Accessed August 1, 2017.
  • Brenner B, Corbridge T, Kazzi A. Intubation and mechanical ventilation of the asthmatic patient in respiratory failure. J Emerg Med. 2009 Aug;37(2 Suppl):S23-34. doi: 10.1016/j.jemermed.2009.06.108. [PubMed]