1. Assess patient’s prior interventions.

2. Assess the following patient’s respiratory status:

  • Rate
  • Rhythm
  • Depth
  • Effort

3. Assess monitors:

  • Oxygenation (SpO2)
  • EtCO2   (with advanced airway or EMMA mounted on non-rebreather mask)
  • Cardiac monitoring if available

4. Determine cause of ventilation issue and/or ventilator alarm using DOPE mnemonic.

Table 1. Trouble shooting - DOPE Algorithm

Recently published USAF EMS protocols

Figure 1. Normal Capnogram, Normal EtCO2: 35-45 mmHg
Figure 2. Endotracheal Tube in Esophagus 

Possible causes:

  • Missed intubation
  • A normal capnogram is the best evidence that the ET tube is correctly positioned.
  • With ET tube in the esophagus, little or no CO2 is present.
Figure 3. Obstruction in Airway or Breathing Circuit 

Possible causes:

  • Partially kinked or occluded artificial airway
  • Presence of foreign body in the airway
  • Obstruction in expiratory limb of breathing circuit
  • Bronchospasm

Source: https://openairway.org/capnography