EFFECT OF CRYSTALLOID AND COLLOID PRELOADING ON UTEROPLACENTAL AND MATERNAL HEMODYNAMIC STATE DURING SPINAL-ANESTHESIA FOR CESAREAN-SECTION

We have studied the effects of crystalloid 1 litre (lactated Ringer's) or colloid 0.5 litre (hydroxyethyl starch) preloading in 26 healthy p arturients undergoing elective Caesarean section under spinal anaesthe sia. Maternal placental uterine artery circulation was measured using a pulsed colour Doppler technique with simultaneous measurement of mat ernal haemodynamics. A high incidence of maternal hypotension was obse rved during spinal anaesthesia in the crystalloid group (62%) but the incidence was lower in the colloid group (38%). Central venous pressur e was increased significantly in both groups after preload but decreas ed shortly after induction of spinal anaesthesia to baseline values. T he mean pulsatility index (PI) in the uterine arteries did not change during preload or spinal block. A surprising finding was the widesprea d variation and some high values for the uterine artery PI after spina l anaesthesia. These individual increases in PI were transient and alw ays returned to baseline values within 2 min. These results suggest th at preloading with either solution is ineffective in preventing matern al hypotension and that changes in maternal heart rate, systolic arter ial pressure and central venous pressure during spinal anaesthesia wer e not associated with rapid individual increases in uteroplacental vas cular resistance. These changes seemed not to have any major effect, h owever, on the clinical condition of the newborn, as assessed by Apgar scores and umbilical artery pH values.