Downloaded from http://emj.bmj.com/ on November 19, 2015 - Published by group.bmj.com
Short report
End-tidal CO2 detection during cadaveric ventilation T J Coats,1 B Morgan,2 C Robinson,3 M Biggs,4 A Adnan,5 G Rutty4 1
Emergency Medicine Academic Group, University of Leicester, Leicester, UK 2 Department of Cancer Studies, University of Leicester, Leicester, UK 3 Forensic Imaging, University Hospitals of Leicester NHS Trust, Leicester, UK 4 East Midlands Forensic Pathology Unit, University of Leicester, Leicester, UK 5 Department of Cardiovascular Sciences, University of Leicester, Leicester, UK Correspondence to Dr T J Coats, Department of Emergency Medicine, University of Leicester, University Road, Leicester LE1 7RH, UK; [email protected] Received 17 April 2015 Revised 19 May 2015 Accepted 20 May 2015 Published Online First 4 June 2015
To cite: Coats TJ, Morgan B, Robinson C, et al. Emerg Med J 2015;32:753–754.
ABSTRACT ‘Life like’ end-tidal CO2 production has been reported in frozen cadaver during intubation training. We report the same phenomenon in a non-frozen cadaveric model used to undertake CT postmortem, with the additional findings of an increase in CO2 with chest compressions and an increase in CO2 after a pause in ventilation. Measurable end-tidal CO2 has been previously reported in a frozen cadaveric model used for intubation training.1 We made the same observation in a non-frozen cadaver undergoing ‘ABC’ interventions as part of a research project into the use of postmortem CT (PMCT) compared with physical postmortem. As part of the PMCT procedure, the cadaver is intubated, and ventilation and chest compressions are used to circulate injected contrast for a contrast-enhanced CT scan to aid the diagnosis of the cause of death. This procedure may also allow
the comparison of different methods of cardiopulmonary resuscitation (CPR). The project had Research Ethics Committee approval and was supported by a Resuscitation Council (UK) grant. Consent was obtained from relatives. The patient was an elderly female without known abnormality of the airway, who had been in a temperature-controlled environment at 4°C for 32 h after death with no other preservation. She was intubated and approximately 60 min later ventilation was commenced. End-tidal CO2 was measured from the start of ventilation using continuous waveform capnography (Propaq CS Monitor, Model 246, Software V.3.7X, Welch Allyn). After 8 min of ventilation, a venous injection of contrast was given via the right antecubital fossa and 2 min of chest compressions performed using a Lucas device. Ventilation was then stopped on an inspiratory hold and whole body CT was undertaken.
Figure 1
End-tidal CO2 waveform.
Figure 2
Change in end-tidal CO2 with ventilation and chest compressions. CPR, cardiopulmonary resuscitation.
Coats TJ, et al. Emerg Med J 2015;32:753–754. doi:10.1136/emermed-2015-204950
753
Downloaded from http://emj.bmj.com/ on November 19, 2015 - Published by group.bmj.com
Short report The configuration of the CO2 trace obtained was similar to that seen in a live patient (figure 1). The initial end-tidal CO2 levels were high (at about 6 kPa), then decreased rapidly (figure 2)—confirming findings previously reported in a frozen cadaver. A novel observation was that the level of CO2 rose again (although at low levels) when CPR was started, presumably due to effective circulation. The PMCT confirmed that some circulation had been achieved as contrast had travelled into the pulmonary vasculature, and also confirmed that the endotracheal tube was situated in the trachea. A further novel finding was that end-tidal CO2 was again higher after the pause in ventilation required for the CT scan, presumably due to diffusion of CO2 down a concentration gradient created by the ventilation-induced fall in alveolar partial pressure, or ongoing bacterial activity.
754
These novel findings will be further investigated to establish whether or not measurement of end-tidal CO2 in cadavers has a role: (a) in a protocol for PMCT (as it may indicate effective ventilation and circulation of contrast) or (b) in the comparison of the effectiveness of different methods of CPR. Contributors TJC drafted the manuscript. All the authors reviewed and revised the draft. Funding Resuscitation Council UK. Competing interests None declared. Ethics approval REC Nottingham 1. Provenance and peer review Not commissioned; externally peer reviewed.
REFERENCE 1
Reid C, Lewis A, Habig K, et al. Sustained life-like waveform capnography after human cadaveric tracheal intubation. Emerg Med J 2015;32:232–3.
Coats TJ, et al. Emerg Med J 2015;32:753–754. doi:10.1136/emermed-2015-204950
Downloaded from http://emj.bmj.com/ on November 19, 2015 - Published by group.bmj.com
End-tidal CO2 detection during cadaveric ventilation T J Coats, B Morgan, C Robinson, M Biggs, A Adnan and G Rutty Emerg Med J 2015 32: 753-754 originally published online June 4, 2015
doi: 10.1136/emermed-2015-204950 Updated information and services can be found at: http://emj.bmj.com/content/32/9/753
These include:
References Email alerting service
This article cites 1 articles, 1 of which you can access for free at: http://emj.bmj.com/content/32/9/753#BIBL Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article.
Notes
To request permissions go to: http://group.bmj.com/group/rights-licensing/permissions To order reprints go to: http://journals.bmj.com/cgi/reprintform To subscribe to BMJ go to: http://group.bmj.com/subscribe/
Short report
End-tidal CO2 detection during cadaveric ventilation T J Coats,1 B Morgan,2 C Robinson,3 M Biggs,4 A Adnan,5 G Rutty4 1
Emergency Medicine Academic Group, University of Leicester, Leicester, UK 2 Department of Cancer Studies, University of Leicester, Leicester, UK 3 Forensic Imaging, University Hospitals of Leicester NHS Trust, Leicester, UK 4 East Midlands Forensic Pathology Unit, University of Leicester, Leicester, UK 5 Department of Cardiovascular Sciences, University of Leicester, Leicester, UK Correspondence to Dr T J Coats, Department of Emergency Medicine, University of Leicester, University Road, Leicester LE1 7RH, UK; [email protected] Received 17 April 2015 Revised 19 May 2015 Accepted 20 May 2015 Published Online First 4 June 2015
To cite: Coats TJ, Morgan B, Robinson C, et al. Emerg Med J 2015;32:753–754.
ABSTRACT ‘Life like’ end-tidal CO2 production has been reported in frozen cadaver during intubation training. We report the same phenomenon in a non-frozen cadaveric model used to undertake CT postmortem, with the additional findings of an increase in CO2 with chest compressions and an increase in CO2 after a pause in ventilation. Measurable end-tidal CO2 has been previously reported in a frozen cadaveric model used for intubation training.1 We made the same observation in a non-frozen cadaver undergoing ‘ABC’ interventions as part of a research project into the use of postmortem CT (PMCT) compared with physical postmortem. As part of the PMCT procedure, the cadaver is intubated, and ventilation and chest compressions are used to circulate injected contrast for a contrast-enhanced CT scan to aid the diagnosis of the cause of death. This procedure may also allow
the comparison of different methods of cardiopulmonary resuscitation (CPR). The project had Research Ethics Committee approval and was supported by a Resuscitation Council (UK) grant. Consent was obtained from relatives. The patient was an elderly female without known abnormality of the airway, who had been in a temperature-controlled environment at 4°C for 32 h after death with no other preservation. She was intubated and approximately 60 min later ventilation was commenced. End-tidal CO2 was measured from the start of ventilation using continuous waveform capnography (Propaq CS Monitor, Model 246, Software V.3.7X, Welch Allyn). After 8 min of ventilation, a venous injection of contrast was given via the right antecubital fossa and 2 min of chest compressions performed using a Lucas device. Ventilation was then stopped on an inspiratory hold and whole body CT was undertaken.
Figure 1
End-tidal CO2 waveform.
Figure 2
Change in end-tidal CO2 with ventilation and chest compressions. CPR, cardiopulmonary resuscitation.
Coats TJ, et al. Emerg Med J 2015;32:753–754. doi:10.1136/emermed-2015-204950
753
Downloaded from http://emj.bmj.com/ on November 19, 2015 - Published by group.bmj.com
Short report The configuration of the CO2 trace obtained was similar to that seen in a live patient (figure 1). The initial end-tidal CO2 levels were high (at about 6 kPa), then decreased rapidly (figure 2)—confirming findings previously reported in a frozen cadaver. A novel observation was that the level of CO2 rose again (although at low levels) when CPR was started, presumably due to effective circulation. The PMCT confirmed that some circulation had been achieved as contrast had travelled into the pulmonary vasculature, and also confirmed that the endotracheal tube was situated in the trachea. A further novel finding was that end-tidal CO2 was again higher after the pause in ventilation required for the CT scan, presumably due to diffusion of CO2 down a concentration gradient created by the ventilation-induced fall in alveolar partial pressure, or ongoing bacterial activity.
754
These novel findings will be further investigated to establish whether or not measurement of end-tidal CO2 in cadavers has a role: (a) in a protocol for PMCT (as it may indicate effective ventilation and circulation of contrast) or (b) in the comparison of the effectiveness of different methods of CPR. Contributors TJC drafted the manuscript. All the authors reviewed and revised the draft. Funding Resuscitation Council UK. Competing interests None declared. Ethics approval REC Nottingham 1. Provenance and peer review Not commissioned; externally peer reviewed.
REFERENCE 1
Reid C, Lewis A, Habig K, et al. Sustained life-like waveform capnography after human cadaveric tracheal intubation. Emerg Med J 2015;32:232–3.
Coats TJ, et al. Emerg Med J 2015;32:753–754. doi:10.1136/emermed-2015-204950
Downloaded from http://emj.bmj.com/ on November 19, 2015 - Published by group.bmj.com
End-tidal CO2 detection during cadaveric ventilation T J Coats, B Morgan, C Robinson, M Biggs, A Adnan and G Rutty Emerg Med J 2015 32: 753-754 originally published online June 4, 2015
doi: 10.1136/emermed-2015-204950 Updated information and services can be found at: http://emj.bmj.com/content/32/9/753
These include:
References Email alerting service
This article cites 1 articles, 1 of which you can access for free at: http://emj.bmj.com/content/32/9/753#BIBL Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article.
Notes
To request permissions go to: http://group.bmj.com/group/rights-licensing/permissions To order reprints go to: http://journals.bmj.com/cgi/reprintform To subscribe to BMJ go to: http://group.bmj.com/subscribe/
