Table 4.

Arterial blood gases during U 46619 infusion (1 μg/kg/min) and changes in PVR and PAP among the three groups of lambs (mean ± SEM)

Protocol	pH	Pco2 (mm Hg)	Po2 (mm Hg)	Base excess (mEq/L)
21% Res	7.34 ± 0.03	42 ± 4	36 ± 5	−4 ± 1
50% Res	7.31 ± 0.02	45 ± 3	46 ± 7	−4 ± 1
100% Res	7.37 ± 0.02†	40 ± 2	42 ± 5	−3 ± 1
Protocol	Baseline PVR immediately prior to infusion of U46619	PVR during U46619 0.5μg/kg/min	% Change in PVR from baseline (0.5 μg/kg/min)
21% Res	0.31 ± 0.03	0.72 ± 0.2‡	258 ± 70
50% Res	0.28 ± 0.05	0.6 ± 0.2‡	275 ± 54
100% Res	0.22 ± 0.02*	0.75 ± 0.2‡	321 ± 81
Protocol	PVR during U46619 1 μg/kg/min	% Change in PVR from baseline (1 μg/kg/min)	Increase in PAP with U46619 at 1 μg/kg/min (mm Hg)
21% Res	1.07 ± 0.25‡	343 ± 77	35 ± 5
50% Res	1.03 ± 0.4‡	401 ± 121	36 ± 3
100% Res	1.12 ± 0.3‡	496 ± 112	36 ± 3

^*p < 0.05 compared with 21% Res.

^†p < 0.05 compared with 50% Res.

^‡p < 0.01 compared with baseline PVR in the same group.