Mild hypercapnia improves brain tissue oxygen tension but not diffusion limitation in asphyxial cardiac arrest: an experimental study in pigs

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

ISSN: 1471-2253