Objective: In this study, we aimed to determine end-tidal carbon dioxide (ETCO₂) and deltaCO₂ levels in patients with Coronavirus Disease 2019 (COVID-19) pneumonia and examine the relationship between these two parameters and the severity of disease.
Methods: Patients with COVID-19 were included in the study. ETCO₂ values were recorded and deltaCO₂ values were calculated. They were divided into two groups: mild-moderate and severe patients. An analysis was performed to determine the threshold values for ETCO₂ and deltaCO₂ in mild-moderate and severe patient groups.
Results: A total of 83 patients were included in our study. Of the patients, 43 (51.8%) patients had mild/moderate disease and 40 (48.2%) had severe disease. The AUC value was 0.910 for ETCO₂ (95% CI; 0.840-0.980, p<0.001) and was 0.927 for DeltaCO₂ (95% CI; 0.864-0.990, p<0.001). To discriminate patients in the severe group, considering a best cut-off value of 22.5 for ETCO₂, the sensitivity and specificity values for this value were 95% and 80%, respectively. Considering a best cut-off value of 11.1 for deltaCO₂, the sensitivity and specificity values for this value were 95% and 77%, respectively. As a result of the DeLong test, the predictive values of deltaCO₂ and ETCO₂ for the severe patient group was found to be better than and similar to PCO2.
Conclusion: We showed that low ETCO₂ and high deltaCO₂ values are safe parameters that can be used to predict the severity of disease in patients who apply and are monitored due to COVID-19 pneumonia.
This study was approved by Atatürk Sanatoryum Training and Research Hospital Ethics Committee, Noninvasive Clinic Ethics Committee (Approval date: 12/12/2020 Number: 2012-KAEK-15/228)
Project Number
yok
References
Lai CC, Wang CY, Wang YH, Hsueh SC, Ko WC, Hsueh PR. Global epidemiology of coronavirus disease 2019 (COVID-19): Disease incidence, daily cumulative index, mortality, and their association with country healthcare resources and economic status. Int J Antimicrob Agents. 2020;55(4):105946. DOI: 10.1016/j.ijantimicag.2020.105946.
Lermuzeaux M, Meric H, Sauneuf B, Girard S, Normand H, Lofaso F, Terzi N. Superiority of transcutaneous CO₂ overend-tidal CO₂ measurement for monitoring respiratory failure in non-intubated patients: A pilot study. J Crit Care. 2016;31(1):150-156. DOI: 10.1016/j.jcrc.2015.09.014
Riaz I, Jacob B. Pulmonary embolism in Bradford, UK: Role of end-tidal CO₂ as a screeningtool. Clin Med (Lond). 2014;14(2):128-133. DOI: 10.7861/clinmedicine.
Kim YW, Hwang SO, Kang HS, Cha KC. The gradient between arterial and end-tidal carbondioxide predicts in-hospital mortality in post-cardiac arrest patient. Am J Emerg Med. 2019;37(1):1-4. DOI: 10.1016/j.ajem.2018.04.025.
Tyburski JG, Collinge JD, Wilson RF, Carlin AM, Albaran RG, Steffes CP. End-tidal CO₂- derived values during emergency trauma surgery correlated without come: A prospective study. J Trauma. 2002;53(4):738-743. DOI: 10.1097/00005373-200210000-00020.
Goh KJ, Choong MCM, Cheong EHT, Kalimuddin S, Duu Wen S, Phua GC, Chan KS, Haja Mohideen S. Rapid progression to acute respiratory distress syndrome: Review of current understanding of critical ıllness from coronavirus disease 2019 (COVID-19) infection. Ann Acad Med Singapore 2020;49:108–118.
Yousuf T, Brinton T, Murtaza G, Wozniczka D, Ahmad K, Iskandar J, Mehta R, Keshmiri H, Hanif T. Establishing a gradient between partial pressure of arterial carbondioxide and end-tidal carbondioxide in patients with acute respiratory distress syndrome. J Investig Med. 2017;65(2):338-341. DOI: 10.1136/jim-2016-000253
Caruso D, Zerunian M, Polici M, Pucciarelli F, Guido G, Polidori T, Rucci C, Bracci B, Tremamunno G, Laghi A. Diagnostic performance of CT lung severity score and quantitative chest CT for stratification of COVID-19 patients. Radiol Med. 2022;127(3):309-317. DOI: 10.1007/s11547-022-01458-9.
Long B, Koyfman A, Vivirito MA. Capnography in the Emergency Department: A Review of Uses, Waveforms, and Limitations. J Emerg Med. 2017;53(6):829-842. DOI: 10.1016/j.jemermed.2017.08.026.
Kerr ME, Zempsky J, Sereika S, Orndoff P, Rudy EB. Relationship between arterial carbon dioxide and end-tidal carbon dioxide in mechanically ventilated adults with severe head trauma. Crit Care Med. 1996;24(5):785-790. DOI: 10.1097/00003246-199605000-00010.
Russell GB, Graybeal JM. Reliability of the arterial to end-tidal carbon dioxide gradient in mechanically ventilated patients with multisystem trauma. J Trauma. 1994;36(3):317-322. DOI: 10.1097/00005373-199403000-00006.
Taghizadieh A, Pouraghaei M, Moharamzadeh P, Ala A, Rahmani F, Basiri Sofiani K. Comparison of end-tidal carbon dioxide and arterial blood bicarbonate levels in patients with metabolic acidosis referred to emergency medicine. J Cardiovasc Thorac Res. 2016;8(3):98-101. DOI: 10.15171/jcvtr.2016.21.
Uzunosmanoğlu H, Emektar E, Dağar S, Çorbacıoğlu ŞK, Çevik Y. Predictive value of capnography for severity of acute gastroenteritis in the emergency department. Am J Emerg Med. 2020;38(6):1159-1162. DOI: 10.1016/j.ajem.2019.158404.
Year 2025,
Volume: 15 Issue: 1, 22 - 26, 28.03.2025
Lai CC, Wang CY, Wang YH, Hsueh SC, Ko WC, Hsueh PR. Global epidemiology of coronavirus disease 2019 (COVID-19): Disease incidence, daily cumulative index, mortality, and their association with country healthcare resources and economic status. Int J Antimicrob Agents. 2020;55(4):105946. DOI: 10.1016/j.ijantimicag.2020.105946.
Lermuzeaux M, Meric H, Sauneuf B, Girard S, Normand H, Lofaso F, Terzi N. Superiority of transcutaneous CO₂ overend-tidal CO₂ measurement for monitoring respiratory failure in non-intubated patients: A pilot study. J Crit Care. 2016;31(1):150-156. DOI: 10.1016/j.jcrc.2015.09.014
Riaz I, Jacob B. Pulmonary embolism in Bradford, UK: Role of end-tidal CO₂ as a screeningtool. Clin Med (Lond). 2014;14(2):128-133. DOI: 10.7861/clinmedicine.
Kim YW, Hwang SO, Kang HS, Cha KC. The gradient between arterial and end-tidal carbondioxide predicts in-hospital mortality in post-cardiac arrest patient. Am J Emerg Med. 2019;37(1):1-4. DOI: 10.1016/j.ajem.2018.04.025.
Tyburski JG, Collinge JD, Wilson RF, Carlin AM, Albaran RG, Steffes CP. End-tidal CO₂- derived values during emergency trauma surgery correlated without come: A prospective study. J Trauma. 2002;53(4):738-743. DOI: 10.1097/00005373-200210000-00020.
Goh KJ, Choong MCM, Cheong EHT, Kalimuddin S, Duu Wen S, Phua GC, Chan KS, Haja Mohideen S. Rapid progression to acute respiratory distress syndrome: Review of current understanding of critical ıllness from coronavirus disease 2019 (COVID-19) infection. Ann Acad Med Singapore 2020;49:108–118.
Yousuf T, Brinton T, Murtaza G, Wozniczka D, Ahmad K, Iskandar J, Mehta R, Keshmiri H, Hanif T. Establishing a gradient between partial pressure of arterial carbondioxide and end-tidal carbondioxide in patients with acute respiratory distress syndrome. J Investig Med. 2017;65(2):338-341. DOI: 10.1136/jim-2016-000253
Caruso D, Zerunian M, Polici M, Pucciarelli F, Guido G, Polidori T, Rucci C, Bracci B, Tremamunno G, Laghi A. Diagnostic performance of CT lung severity score and quantitative chest CT for stratification of COVID-19 patients. Radiol Med. 2022;127(3):309-317. DOI: 10.1007/s11547-022-01458-9.
Long B, Koyfman A, Vivirito MA. Capnography in the Emergency Department: A Review of Uses, Waveforms, and Limitations. J Emerg Med. 2017;53(6):829-842. DOI: 10.1016/j.jemermed.2017.08.026.
Kerr ME, Zempsky J, Sereika S, Orndoff P, Rudy EB. Relationship between arterial carbon dioxide and end-tidal carbon dioxide in mechanically ventilated adults with severe head trauma. Crit Care Med. 1996;24(5):785-790. DOI: 10.1097/00003246-199605000-00010.
Russell GB, Graybeal JM. Reliability of the arterial to end-tidal carbon dioxide gradient in mechanically ventilated patients with multisystem trauma. J Trauma. 1994;36(3):317-322. DOI: 10.1097/00005373-199403000-00006.
Taghizadieh A, Pouraghaei M, Moharamzadeh P, Ala A, Rahmani F, Basiri Sofiani K. Comparison of end-tidal carbon dioxide and arterial blood bicarbonate levels in patients with metabolic acidosis referred to emergency medicine. J Cardiovasc Thorac Res. 2016;8(3):98-101. DOI: 10.15171/jcvtr.2016.21.
Uzunosmanoğlu H, Emektar E, Dağar S, Çorbacıoğlu ŞK, Çevik Y. Predictive value of capnography for severity of acute gastroenteritis in the emergency department. Am J Emerg Med. 2020;38(6):1159-1162. DOI: 10.1016/j.ajem.2019.158404.
Altun, M. E., Emektar, E., Çorbacıoğlu, Ş. K., Çevik, Y. (2025). Evaluation of the relationship between ETCO2 and delta CO2 pressure and the severity of disease in COVID-19 pneumonia. Clinical and Experimental Health Sciences, 15(1), 22-26. https://doi.org/10.33808/clinexphealthsci.1322620
AMA
Altun ME, Emektar E, Çorbacıoğlu ŞK, Çevik Y. Evaluation of the relationship between ETCO2 and delta CO2 pressure and the severity of disease in COVID-19 pneumonia. Clinical and Experimental Health Sciences. March 2025;15(1):22-26. doi:10.33808/clinexphealthsci.1322620
Chicago
Altun, Mehmet Emin, Emine Emektar, Şeref Kerem Çorbacıoğlu, and Yunsur Çevik. “Evaluation of the Relationship Between ETCO2 and Delta CO2 Pressure and the Severity of Disease in COVID-19 Pneumonia”. Clinical and Experimental Health Sciences 15, no. 1 (March 2025): 22-26. https://doi.org/10.33808/clinexphealthsci.1322620.
EndNote
Altun ME, Emektar E, Çorbacıoğlu ŞK, Çevik Y (March 1, 2025) Evaluation of the relationship between ETCO2 and delta CO2 pressure and the severity of disease in COVID-19 pneumonia. Clinical and Experimental Health Sciences 15 1 22–26.
IEEE
M. E. Altun, E. Emektar, Ş. K. Çorbacıoğlu, and Y. Çevik, “Evaluation of the relationship between ETCO2 and delta CO2 pressure and the severity of disease in COVID-19 pneumonia”, Clinical and Experimental Health Sciences, vol. 15, no. 1, pp. 22–26, 2025, doi: 10.33808/clinexphealthsci.1322620.
ISNAD
Altun, Mehmet Emin et al. “Evaluation of the Relationship Between ETCO2 and Delta CO2 Pressure and the Severity of Disease in COVID-19 Pneumonia”. Clinical and Experimental Health Sciences 15/1 (March 2025), 22-26. https://doi.org/10.33808/clinexphealthsci.1322620.
JAMA
Altun ME, Emektar E, Çorbacıoğlu ŞK, Çevik Y. Evaluation of the relationship between ETCO2 and delta CO2 pressure and the severity of disease in COVID-19 pneumonia. Clinical and Experimental Health Sciences. 2025;15:22–26.
MLA
Altun, Mehmet Emin et al. “Evaluation of the Relationship Between ETCO2 and Delta CO2 Pressure and the Severity of Disease in COVID-19 Pneumonia”. Clinical and Experimental Health Sciences, vol. 15, no. 1, 2025, pp. 22-26, doi:10.33808/clinexphealthsci.1322620.
Vancouver
Altun ME, Emektar E, Çorbacıoğlu ŞK, Çevik Y. Evaluation of the relationship between ETCO2 and delta CO2 pressure and the severity of disease in COVID-19 pneumonia. Clinical and Experimental Health Sciences. 2025;15(1):22-6.