Reduction of occurrence of hypotension during spinal anaesthesia for caesarean section : Prophylactic intramuscular ephedrine versus fluid preload

الملخص EN

Hypotension during spinal anaesthesia has traditionally been managed by fluid preloading.

However studies and reports have regularly appeared in the literature disputing the value of such management.

With this in mind,we comparerd the efficacy of prophylactic intramuscular ( im) ephedrine with fluid preloading in the prevention of maternal hypotension during spinal anaesthesia for Caesarean sectionfCS).

Fourty women undergoing elective cs at term were allocated randomly to receive either a preload of 20ml / kg of norma! saline over 10-15 min immediately before spinal anaesthesia (fluid group) or prophylactic ephedrine 50 mg im 10 min before spinal anaesthesia ( ephedrine group).

The two techniques were compared for their maternal and neonatal effects.

Moderate hypotension was defined as>20% reduction in systolic blood pressure ( SAP) and severe hypotension as > 30% reduction in SAP.

Blood presure was significantly decreased in both groups at different time intervals and the decrease was significant more in the fluid group in comparison to the ephedrine group.

The difference in the incidence of hypotension was only significant at 5 and 10 min after induction of spinal anaesthesia in the fluid group in comparison to the ephedrine group(p<0.05).

The incidence of moderate hypotension was significantly higher in the fluid group (80% vs 40%, p< 0.05) while there was no significant difference in the incidence of severe hypotension between the two .groups.

The total dose of rescue ephedrine was significantly lower in the ephedrine group compared to the fluid group (4.8+5.71 mg vs I5.9±8.55, p< 0.05).

The incidence of nausea and vomiting was higher in the fluid group (p< 0.05, 0.01 respectivefy).Neonatal Apgar score was only significanly higher at one min in the ephedrine group compared with the fluid group (7.6±0.5 vs 6.75±0.05,p< 0.05).

There was no significant difference in umbilical blood pHpo2,paco2 between the two groups.

Oxygen saturation was significantly higher in the ephedrine group in both umbilical arterial and venous blood (p< 0.01).

We concluded from this study that, ephedrine 50mg given intramusculary 10 minutes before induction of spinal anesthesia reduces the incidence of hypotension and the total dose of rescue ephedrine therapy than preloading with 20ml/kg crystalloid during spinal anesthesia for GS The incidence of nausea and vomiting was also reduced and foetal outcome was improved.

However this dose of ephedrine did not completely eliminate hypotension, nausea and vomiting .Perhaps a larger ephedrine dose or using fluid preload in addition to im ephedrine may have improved these further.