BACKGROUND: Cesarean section (C-section) is the most frequently performed surgery in obstetrics, generally using subarachnoid block (SAB) or epidural block for anesthesia. The previous studies have shown the effectiveness of fluid loading and vasopressor pretreatment in preventing maternal hypotension (decreased blood pressure), the most common side effect of SAB. However, the timing of hypotension in response to these treatments has not been analyzed. AIM: This study therefore aimed to compare the effects of crystalloid or colloid fluid loading and vasopressor pre-treatment on the timing of hypotension in cases of C-section under SAB anesthesia. METHODS: The study was a single-blind randomized controlled clinical trial with three treatment groups: Group I, 10 mL/kgBW crystalloid solution (Ringer’s lactate) loading 10 min before SAB; Group II, 5 mL/kgBW colloid fluid (gelatin) loading 10 min before SAB; and Group III, pretreatment with 0.1 mg/kgBW vasopressor (ephedrine) intravenous bolus just before SAB. RESULTS: Significant differences in mean blood pressure between groups were observed between the second and 8th min (p < 0.05). Hypotension was observed in the crystalloid group within the first 5 min, while average blood pressure was relatively stable all groups after the first 10 min. In addition, hypotension occurred more frequently in the crystalloid group (nine subjects, 45%), compared with the colloid and vasopressor groups (two subjects per group, 10%; p < 0.05). CONCLUSION: Hypotension occurred more rapidly and more frequently when crystalloid loading was utilized, compared with colloid loading or vasopressor pretreatment. Administration of colloid fluid loading and vasopressor pretreatment has been shown to prevent hypotension in SAB anesthesia.

Caesarean section (SC) is the most frequently performed surgery in obstetrics. Subarachnoid block (SAB) and epidural block are the most widely used anesthetic techniques in CS surgery. Objectives To analyze the effect of loading crystalloid fluid and administration of vasopressors on the time of occurrence of a decrease in blood pressure in SC with SAB anesthesia. Method single-blind randomized controlled clinical trial consisting of 2 treatment groups, namely crystalloid fluid loading and vasopressor pre-treatment. The Results There was a significant difference in mean blood pressure between the crystalloid group and the vasopressor group at 2 to 8 minutes (p<0.05). The average systolic blood pressure for 46 minutes in the three groups showed that the decrease in blood pressure occurred first in the crystalloid group compared to the vasopressor group, and hypotension occurred at 5 minutes in the crystalloid group. After the first 10 minutes, average blood pressure tends to be relatively stable. There was a significant difference in the incidence of hypotension, which occurred more in the crystalloid group, which was 9 or 45%, the vasopressor group with hypotension was 2 or 10% (p<0.05). The incidence of decreased blood pressure was found to be more common with crystalloid loading than with vasopressor pretreatment, in accordance with the findings of previous studies. The incidence of decreased blood pressure in SC with SAB anesthesia was faster and more common with loading crystalloids than pretreatment with vasopressors. Administration of vasopressor pretreatment has been shown to prevent the incidence of a decreased blood pressure in SAB anesthesia.