Table 3

- Arterial blood gas analysis.

Arterial blood gas analysis	Beginning	10^th min	30^th min	60^th min	Extubation
PO₂ (mm Hg)
High-flow	98 ± 18	100 ± 20	103 ± 13	110 ± 9	104 ± 34
Low-flow	94 ± 25	101 ± 20	102 ± 19	112 ± 14	101 ± 25
P-value	0.440	0.914	0.563	0.942	0.933
PCO₂ (mm Hg)
High-flow	35 ± 4	39 ± 4	40 ± 4	41 ± 3	43 ± 6
Low-flow	36 ± 5	36 ± 5	39 ± 5	41 ± 3	40 ± 5
P-value	0.716	0.039	0.252	0.923	0.064
SaO₂ (%)
High-flow	98 ± 3	96 ± 3	96 ± 4	97 ± 1	96 ± 4
Low-flow	97 ± 3	95 ± 4	96 ± 3	97 ± 2	96 ± 2
P-value	0.344	0.715	0.875	0.725	0.961
HCO₃ (mmol/L)
High-flow	23.7 ± 1.2	20.7 ± 1.5	20.4 ± 1.9	20.1 ± 1.0	20.1 ± 1.1
Low-flow	20.7 ± 1.6	20.5 ± 2.7	20.3 ± 1.9	20.3 ± 1.6	21.0 ± 1.8
P-value	0.328	0.962	0.971	0.718	0.106
BE (mmol/l) (base excess)
High-flow	2.3 ± 1.4	3.9 ± 1.7	5.1 ± 1.3	5.0 ± 1.2	4.9 ± 1.5
Low-flow	2.2 ± 1.6	3.9 ± 2.1	4.6 ± 2.0	4.7 ± 1.7	4.3 ± 2.1
P-value	0.563	0.923	0.455	0.214	0.341
PH
High-flow	7.39 ± 0.05	7.36 ± 0.06	7.34 ± 0.06	7.32 ± 0.05	4.9 ± 1.5
Low-flow	7.39 ± 0.06	7.36 ± 0.07	7.36 ± 0.06	7.31 ± 0.06	4.3 ± 2.1
P-value	0.990	0.971	0.524	0.731	0.138
Lactate (mmol/L)
High-flow	0.7 ± 0.3	0.9 ± 0.4	1.1 ± 0.6	1.3 ± 0.8	1.0 ± 0.3
Low-flow	0.7 ± 0.3	0.9 ± 0.4	1.3 ± 0.6	1.4 ± 0.8	1.0 ± 0.3
P-value	0.971	0.990	0.317	0.857	0.971

PO₂: oxygen saturation, PCO₂: pressure of carbon dioxide, SaO₂: oxygen saturation, HCO₃: Bicarbonate, BE: fbase excess, PH: arterial hydrogen ion concentration