primiparas with peridural anesthesia showed significantly less decrease in arterial oxygen saturation ( 1.7 +/- 1.4 % ; p less than .001 ; n = 15 ) , superior scores on the visual pain analog scale ( 3.5 +/- 2.0 ) , and a significantly better neonatal acid-base status ( ph 7.29 +/- 0.06 ; p = .01 ; base excess -6.4 +/- 2.2 ; p less than .05 ) as compared with primiparas treated with meperidine and nitrous oxide ( sao2 7.2 +/- 3.9 % ; visual pain analog scale 7.1 +/- 1.2 ; ph 7.21 +/- 0.1 ; base excess -9.5 +/- 4.5 ; n = 16 ) .
C0025376
meperidine
C0030193
pain