The utility of ETCO2 value in predicting the progress of the disease and mortality risk in hospitalized patients with COVID-19 pneumonia

Aim: End-tidal CO2 (ETCO2) levels are reflective of the ventilatory and metabolic/perfusion status of a patient, regardless of his/her SpO2 values. This study aimed to investigate the utility of ETCO2values in predicting the need for intubation, ICU admission, and mortality in hospitalized patients with COVID-19 pneumonia. Material and Method: A total of 108 hospitalized patients with COVID-19 pneumonia were included. Data on respiratory parameters (oxygen saturation, ETCO2, and respiratory rate [RR]- with and without O2 [w/wo O2]) and laboratory parameters were recorded. Results: The need forintensive care unit(ICU) admission was associated with significantly higher ETCO2 values (wO2:27.9 (4.6) vs. 18.6(8.4), p=0.040; woO2: 30.1(4.9) vs. 23.8(6.9), p=0.040). Mortality was associated with higher likelihood of higher RR (wO2:32.4(5.8) vs. 24.6(6.8), p=0.002) and lower oxygen saturation (wO2:92.9(3.8) vs. 95.5(4.2), p=0.025; woO2:87.1(5.7) vs. 91.8(6.6), p=0.013). Presence vs. lack of intubation need was associated with significantly increased likelihood of saturation (wO2:93.1(5.3) vs. 95.9(3.8), p=0.013; woO2:87.6(8.3) vs. 92.3(5.9), p=0.007). Hospital discharge vs. ICU stay was associated with significantly higher ETCO2 values (wO2:27.9 (4.6) vs. 18.6(8.4), p=0.040; woO2: 30.1(4.9) vs. 23.8(6.9), p=0.040) Conclusion: Our findings revealed the association of decreased ETCO2 (w/wo O2) values with a lower likelihood of hospital discharge and increased likelihood of ICU transfer. Low oxygen saturation levels related the increased risk of both intubation need and mortality in hospitalized COVID-19 patients.