Serial plasma oncotic pressure levels and echoencephalography during and after delivery in severe pre-eclampsia

Plasma colloid osmotic pressure (PCOP) and echoencephalograms were monitored serially during and after labour in nine nulliparous severe pre-eclamptics receiving parenteral fluids, including infusions of magnesium sulphate and hydralazine. Nine normotensive, age-matched, nulliparous women in labour served as controls. PCOP, lower in the pre-eclamptics (16.1 +/- SD 0.6 mm Hg vs 19.9 +/- 0.7 mm Hg in controls, p less than 0.001) before the start of parenteral infusions, decreased in both groups and at delivery it was 14.1 +/- 0.5 mm Hg in the hypertensive women and 17.2 +/- 0.6 mm Hg in the controls p less than 0.001). After reaching a nadir between 16 and 18 h post partum (pre-eclamptics: 13.8 +/- 0.5 mm Hg; controls 16.2 +/- 0.8 mm Hg; p less than 0.001) the levels rose and at 6 weeks post partum they were greater in the pre-eclamptics (26.2 +/- 1.1 mm Hg vs 22.7 +/- 0.8 mm Hg; p less than 0.01) although the blood pressure in this group had returned to normal. Middle cerebral ventricle width was similar in the pre-eclamptic and normotensive women and remained unchanged during labour and 1 day and 6 weeks post partum. No echographic evidence of brain swelling or symptoms suggestive of pulmonary congestion were observed in either group. The potentially dangerous low PCOPs during and after labour in pre-eclamptic women emphasise the need for minimising crystalloid therapy in pre-eclamptics during labour.