Table 2.
PaCO2 and EtCO2 pairs at admission and after 24 h.
| Variable | Overall n = 105 |
Survivors n = 77 |
Non-survivors n = 28 |
p value |
|---|---|---|---|---|
| Initial measures | 105 (100) | 76 (99) | 28 (100) | |
| CO2 gap, kPa | 1.64 ± 1.09 | 1.42 ± 0.92 | 2.26 ± 1.30 | < 0.001 |
| PaCO2, kPa | 6.26 ± 1.03 | 6.17 ± 0.96 | 6.48 ± 1.18 | |
| EtCO2, kPa | 4.61 ± 0.78 | 4.76 ± 0.74 | 4.23 ± 0.76 | |
| PaCO2 < 15 min of EtCO2 | 42 (40) | 30 (39) | 13 (46) | |
| PaCO2 < 30 min of EtCO2 | 60 (57) | 39 (51) | 21 (75) | |
| PaCO2 ≥ 30 min of EtCO2 | 45 (43) | 38 (49) | 7 (25) | |
| Measures at 24 h | 75 (71) | 53 (70) | 22 (79) | |
| CO2 gap, kPa | 0.64 ± 0.82 | 0.58 ± 0.86 | 0.78 ± 0.70 | 0.108 |
| PaCO2, kPa | 5.12 ± 0.60 | 5.19 ± 0.59 | 4.91 ± 0.58 | |
| EtCO2, kPa | 4.46 ± 0.79 | 4.59 ± 0.82 | 4.15 ± 0.63 | |
| Hours since admission | 18.6 ± 7.8 | 19 ± 8.0 | 17.7 ± 7.5 |
Data was complete. Numbers are presented with percentages of total in parentheses. Continuous variables are reported as mean ± SD (standard deviation). The CO2 gap and the PaCO2 variables were skewed; however, the mean ± SD was presented due to the use of these parameters in the Bland–Altman plots. CO2 gap = PaO2—EtCO2.
For the measures at 24 h there was no time delay measurement of EtCO2 and PaCO2.