Impact of Gas Delivery Systems on Imaging Studies of Human Cerebral Blood Flow

Table 2

CBF results are shown for both circuits and each gas.

GAS	Hudson mask circuit CBF (mL min^−1)	(SD)	Mapleson A circuit CBF (mL min^−1)	(SD)
Medical air	571	108	515.6	120
Oxygen	557 (−2.4%)	142	440.2 (−14.6%)*	89
Carbogen	624 (+9.8%)*	169	681.7 (+32.2%)***	148

Figures are mean values and standard deviations are also given. Figures in brackets represent the percentage change in mean value compared to air. Significance values are calculated using paired t-test in comparison with medical air on the same breathing circuit ^∗𝑃<0.05, ^∗∗𝑃<0.01, ^∗∗∗𝑃<0.001.