Comparison of three fluid regimens for preloading in elective caesarean section under spinal anaesthesia

The most common problem associated with subarachnoid block (SAB) for caesarean section remains the rapid onset of profound hypotension. This study was designed to compare the incidence of hypotension after preloading with Ringer's Lactate, Hydroxyethylstarch and combination prior to SAB in caesarean section. Ninety non-labouring ASA grade 1 and 2, aged 20-35 years, weight and height was 45-60kg and 153-165cm respectively divided randomly into three groups. Group-RL received Ringer's Lactate 20ml/kg as preloading fluid. Group-H received Hydroxyethylstarch-6% 8ml/kg and Group-RLH received preloading fluid with combination of Ringer's Lactate 10ml/kg and Hydroxyethylstarch-6% 4ml/kg. Blood pressure (Systolic, Diastolic & Mean arterial pressure) was measured every 5 minute for 20 minute and every 10 minutes thereafter. Hypotension was less in Group-RLH (6.7%) whereas in Group-H and Group-RL hypotension was 20% and 47.7% respectively. Systolic blood pressure decreased significantly in all three groups. But the decreasing was less in Group-RLH than other two groups. Less IV fluid was required in Group-RLH (403ml) and Group-H (577ml) in comparison to Group-RL (1032ml) to prevent and treat peroperative hypotension. No ephedrine was needed in Group-RLH. Variation in Pulse rate was not significant in Group-RLH (p=0.061). But in other two groups it was highly significant (Group RL p≤0.001 and Group H p=0.004). There was no significant difference in neonatal outcome between three groups. Preloading with low volume colloid (4ml/kg) plus crystalloid (10ml/kg) is superior to crystalloid or colloid alone.