There was a significant decline in PaCO@ in the nCPAP group ( median of -@ mm Hg -LSB- @th-@th quantile , -@ to @ -RSB- ) as compared with the control group ( median of @ mm Hg -LSB- -@ to @ -RSB- ; P = @ ; @ % confidence interval -LSB- CI -RSB- for location shift = -@ to -@ ) .