Table 1.
Comparison of characteristics between mild hypercapnia and normocapnia
| Variables | Hypercapnia (n = 6) | Normocapnia (n = 6) | P value |
|---|---|---|---|
| Survival for 12 h | 6/6 | 5/6 | 1 |
| Weight, kg | 39.7 ± 1.2 | 40 ± 0.9 | 0.835 |
| Duration of asphyxia, minutes | 8.1 ± 0.8 | 8.3 ± 1.1 | 0.789 |
| Shocks | 1 (0, 2) | 1 (1, 2) | 1 |
| Duration of CPR, minutes | 4.4 ± 1.8 | 5.6 ± 1.2 | 0.248 |
| Epinephrine, mg | 0.8 ± 0.4 | 0.9 ± 0.6 | 0.916 |
| Hemoglobin, g/L | 149 ± 7 | 146 ± 8 | 0.54 |
| Pao2, mmHg | |||
| Baseline | 82 ± 12 | 88 ± 13 | 0.432 |
| ROSC 1 h | 99 ± 14 | 107 ± 7 | 0.221 |
| ROSC 6 h | 83 ± 4 | 93 ± 8 | 0.043 |
| ROSC 12 h | 77 ± 4 | 86 ± 5 | 0.007 |
| Paco2, mmHg | |||
| Baseline | 39 ± 2 | 40 ± 2 | 0.958 |
| ROSC 1 h | 52 ± 3 | 41 ± 2 | < 0.001 |
| ROSC 6 h | 51 ± 2 | 40 ± 1 | < 0.001 |
| ROSC 12 h | 50 ± 3 | 39 ± 2 | < 0.001 |
| AJDo2, vol% | |||
| Baseline | 6.3 ± 0. 5 | 6.1 ± 0. 8 | 0.666 |
| ROSC 1 h | 4.7 ± 1.4 | 5.7 ± 0.6 | 0.13 |
| ROSC 6 h | 3.9 ± 0.5 | 4 ± 0.9 | 0.91 |
| ROSC 12 h | 4 ± 1.5 | 4.3 ± 0.6 | 0.7 |
| LOI, mmol/L/vol% | |||
| Baseline | 0.12 ± 0.05 | 0.11 ± 0.04 | 0.807 |
| ROSC 1 h | 0.27 ± 0.06 | 0.21 ± 0.05 | 0.095 |
| ROSC 6 h | 0.22 ± 0.13 | 0.27 ± 0.11 | 0.578 |
| ROSC 12 h | 0.31 ± 0.11 | 0.3 ± 0.08 | 0.974 |
Data were expressed as mean ± SD (standard deviation) or median (interquartile range). Except for the baseline, data of Pao2, Paco2, AJDo2, and LOI after ROSC were calculated from 5 pigs survived for the study period
CPR Cardiopulmonary resuscitation, ROSC Return of spontaneous circulation, Pao2 Pressure of arterial oxygen, Paco2 Pressure of arterial carbon dioxide, AJDo2 Arteriojugular oxygen content difference, LOI Lactate oxygen index