To be attached to the BVM circuit when ventilating or oxygenating a patient e.g.:

  • Cardiac arrest or Peri-arrest - aids recognition of pulselessness, apnoea, quality of CPR or ROSC
  • Unconscious (Medical or Trauma)
  • Rapid sequence induction
  • Mandatory with all advanced airway adjuncts - aids confirmation of endotracheal tube placement

Nasal adapter to be used:

  • Post-sedation where level of response drops (e.g. RASS minus 2 or lower)
  • Unconscious patients where BVM is not necessary or impractical
  • High risk or peri-arrest patients where tolerated (e.g. symptomatic STEMI, cardiogenic shock etc.)
  • None
Patient Factors & Considerations
  • End tidal CO2 measures the level of expired carbon dioxide at the peak of the expiratory phase as a guide to ventilatory effectiveness  
  • Unreliable in patients under 10kg
  • Not to be used for general monitoring of respiratory rates in uncomplicated cases
  • Normal reference range is 35 - 45 mmHg, but varies in unsealed circuits with a mixture of gases (e.g. OPA/BVM or Nasal)
  • Oxygen mask can be placed over the nasal adapter
  • Waveform shape is particularly helpful in conjunction with the reading in mmHg
  • Nasal monitoring may require support with tape if necessary. An oral breath option may be seen occasionally
  • The adapter should be placed behind the bacterial filter as pictured
  • Extremely low values may be due to death / cardiac arrest, misplaced or displaced endotracheal tube or metabolic derangement
  • Apply sound judgement to troubleshoot unanticipated low values
  • ROSC patients may have high values initially - this should not be actively corrected too early (e.g. hyperventilation) as per cardiac arrest CPG
  • Select the appropriate adapter (nasal or ventilation circuit)
  • The 2 wired sensors will click into place by aligning the two blue arrows with the design of the adapter (Pic 1)
  • Misaligned sensors will not provide satisfactory readings
  • Ventilation circuits - the adapter must be positioned behind the bacterial filter (Pic 2)
  • Nasal monitoring - should be applied as shown. Tape support optional (Pic 3)

CPG111 end tidal arrows

Pic 1 - Align Blue Arrows with design features

CPG 111 Circuit filter

Pic 2 - Routine ventilation circuit order


Pic 3 - Nasal monitoring appplication


CPG111 Corpuls capnogram

Pic 4 - Typical Corpuls end tidal waveform display

  • Consistent and reliable waveforms and associated values depend on attention to detail in application
Additional Information
  • Further reading on capnography is widely available, including here


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