Prognostication of out-of-hospital cardiac arrest patients by 3-min end-tidal capnometry level in emergency department

Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations

“… 124 The 2 EvUps are included in Appendix CSupplement Appendix C-9a and C-9b. A search from December 2013 to November 2019 identified 7 new observational studies 74 , 80 , 125 , 126 , 127 , 128 , 129 in addition to the previous SysRev. 124 The task force discussed the low likelihood of an updated SysRev leading to a change in treatment recommendations based on the available studies, and therefore did not prioritize this topic for a SysRev at this time.…”

Modeling the impact of ventilations on the capnogram in out-of-hospital cardiac arrest

“…Resuscitation guidelines highlight that an increase of ETCO 2 during CPR may indicate ROSC, and that low ETCO 2 values may reflect a poor patient prognosis. However, studies in this field have not yet achieved high sensitivity and specificity in ROSC detection, nor reported a strong correlation between the ETCO 2 level and resuscitation outcome [16][17][18][19][20]24]. We suggest that, since the ETCO 2 level varies significantly with ventilation rate, this parameter may act as an important confounding factor in the cited studies.…”

“…Waveform capnography, i.e., continuous measurement of CO 2 concentration with time, enables monitoring of ETCO 2 during CPR. Current advanced life support (ALS) resuscitation guidelines [12,13] emphasize the potential role of waveform capnography in monitoring CPR quality [14,15], in the early recognition of return of spontaneous circulation (ROSC) during CPR [16,17], and as a potential indicator of patient outcome [18][19][20].…”

“…Recent studies have modeled the influence of chest compression quality (compression depth and rate) and ventilation rate on ETCO 2 during CPR using multivariate analysis [14,15]. Studies on ROSC detection and patient outcome rely on the comparison of measured ETCO 2 levels [16][17][18][19][20]24]. However, animal studies have suggested that ventilation rate significantly influences ETCO 2 levels [25].…”

BET 1: Can the value of end tidal CO2prognosticate ROSC in patients coming into emergency department with an out-of-hospital cardiac arrest (OOHCA)?

“…(3) Big variance on time taken to initiate resuscitation, quality of compressions and use of different methods to deliver compressions between studies. (4) Presence of serious inconsistency, as measured by the degree of heterogeneity (p<0.001 and I 2 value of 98.5%)The average ETCO 2 level was 25 mm Hg in participants with ROSCThe mean difference in ETCO 2 was 12.7 mm Hg (95% CI 10.3 to 15.1) between participants with and without ROSC (p<0.001)The mean difference in ETCO 2 was not modified by the receipt of sodium bicarbonate, uncontrolled minute ventilation or era of resuscitation guidelinesThe overall quality of data by Grades of Recommendations, Assessment, Development and Evaluation criteria is very low, but there are currently no prospective dataPoon  et al ,  2016,2 Hong Kong319 patientsProspective cohort studyA 3 min ETCO 2  ≤10 mm Hg was associated with poor prognosis and low chance of ROSCA 3 min ETCO 2  >10 mm Hg was a predictor of ROSC with OR 18.16 (95% CI 4.79 to 51.32, p<0.001). In other words, when cardiac arrested, for a patient with a 3 min ETCO 2  > 10 mm Hg the odds of ROSC was 18 times higher than those with ETCO 2   ≤10 mm HgLarge number of patients excluded due to improper documentation of the use of ETCO 2 (approximately one-third).…”