Colourimetric CO2 detector versus capnography for confirming ET tube placement
Date First Published:
November 24, 2001
Last Updated:
May 15, 2003
Report by:
Kerstin Hogg, Clinical Research Fellow (Manchester Royal Infirmary)
Search checked by:
Stewart Teece, Manchester Royal Infirmary
Three-Part Question:
In an [emergency intubation] is [a colourimetric carbon dioxide detector as reliable as capnography] at [verifying endotracheal tube placement]?
Clinical Scenario:
A 30 year old man is brought to the emergency department with a GCS of 8 after falling down stone steps while drunk. Although he has not vomited, you are concerned that he cannot protect his airway. You decide to do a rapid sequence induction. As you organise and check your equipment, you ask the nurse to bring the departmental capnograph to the bedside. She tells you that it is still in ITU where it was left after transferring the last intubated patient. She does, however, suggest you use a disposable colourimetric CO2 detector found in the paediatric arrest trolley. Should you wait five minutes while the capnograph is brought from ITU, or would the colourimetric indicator be just as accurate?
Search Strategy:
Medline 1966-02/03 using the OVID interface.
Search Details:
[(exp Carbon Dioxide OR end-tidal.mp OR exp Capnography OR carbon dioxide.mp OR capnograph$.mp) AND (colorimetric.mp OR exp Colorimetry OR colourimetric.mp)] LIMIT to human AND English language.
Outcome:
Altogether 69 papers were found of which four were relevant to the question. Details of these papers are shown in the table.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Colorimetric end-tidal carbon dioxide monitoring for tracheal intubation. Goldberg JS, Rawle PR, Zehnder JL, et al. 1990, UK | 62 men aged 18-70 years old, ASA I, II and III. Simulated difficult intubation drill, using laryngoscope to increase larynoscopy grade | Prospective observational study | 3 separate observers recorded time to recognition of tracheal and oesophageal intubation, by observing IR capnography, FEF end-tidal colourimeter, and auscultaion respectively | All three methods confirmed correct positioning in 100% (n=51) cases. Colourimeter and capnograph were faster than chest auscultation. All oesophageal intubations (n=11) confirmed by all 3 methods. One oesophageal intubation gave mild colour change but correctly interpreted | Study only used haemodynamically stable patients Observers were specialist anaesthetic staff as were those intubating Observers not blinded to other detection methods |
| Efficacy of the FEF colorimetric end-tidal carbon dioxide detector in children. Anton WR, Gordon RW, Jordon TM, et al. 1991, USA | 60 emergency intubations, out with theatre – respiratory failure n=29, CPR n=9, self-extubation n=7, ET tube changen=6, airway protection n=3. ? other 6 | Prospective observational study | Observation of colour change in FEF colourimeter within 6 breaths post intubation. Observation of a positive signal from portable TRIMED IR CO2 detector within 6 breaths post intubation | Positive signal of exhaled CO2 produced within 6 breaths by 59 of 60 by FEF detector, and 58 of 60 by TRIMED.Of the 9 CPR patients 5 showed a colour change that was 'subtle', into the brown range. One patient receiving CPR took 20 breaths before a positive signal was received in either | Doctors were presumably anaesthetists There were no oesophageal intubations |
| Efficacy of the FEF colourimetric end-tidal carbon dioxide detector in children. Kelly JS, Wilhoit RD, Brown RE, et al. 1992, USA | 20 children age 6 months to 8 years undergoing elective anaesthesia | Prospective observational study | Colour change in Fenem CO2 detector versus IR capnographer reading in 1. spontaneous mask ventilation 2. post tracheal intubation10 breaths during each point were monitored | Of total 400 breaths, 398 registered yellow colour in the FEF colourimeter with expiration. This correlated with capnography readings. 2 breaths fell into brown range – both of these during mask ventilation, corrected by mask adjustment | All patients haemodynamically stable, with optimal intubating conditions There were no oesophageal intubations Participants were specialist anaesthetists |
| Rapid detection of oesophageal intubation: take care when using colourimetric capnometry. Puntervoll SA, Soreide E, Jacewicz W et al. 2002, Norway | 14 female patients undergoing general anaesthesia. All had both tracheal and oesophageal tubes passed CO2 v capnography |
Experimental study | Detection of tracheal placement | 100% in both devices | Not emergency intubation |
| Detection of oesophageal misplacement | In 5 patients with expired air placed in the oesophagus the colourimetric changed colour |
Author Commentary:
There have been no studies addressing the use of these devices exclusively within the emergency department.
Bottom Line:
The colourimetric CO2 detector is as accurate as IR capnography at detecting tracheal intubation, but is potentially less accurate at detecting oesophageal intubation.
References:
- Goldberg JS, Rawle PR, Zehnder JL, et al.. Colorimetric end-tidal carbon dioxide monitoring for tracheal intubation.
- Anton WR, Gordon RW, Jordon TM, et al.. Efficacy of the FEF colorimetric end-tidal carbon dioxide detector in children.
- Kelly JS, Wilhoit RD, Brown RE, et al.. Efficacy of the FEF colourimetric end-tidal carbon dioxide detector in children.
- Puntervoll SA, Soreide E, Jacewicz W et al.. Rapid detection of oesophageal intubation: take care when using colourimetric capnometry.