THE INFLUENCE OF INTRATHECAL FENTANYL ON THE CHARACTERISTICS OF SUBARACHNOID BLOCK FOR CESAREAN-SECTION

Forty healthy parturients scheduled for elective Caesarean section wer e randomly allocated to receive either 0.3 mi 0.9% saline (control gro up, n = 20) or 15 mu g (0.3 mi) fentanyl (treatment group, n= 20) adde d to 2.5 ml 0.5% hyperbaric bupivacaine given intrathecally in the sit ting position. A sensory block to T-4 was achieved after 6.5 min in th ose who received fentanyl compared to 8.0 min in the control group; th is was not significantly different. The highest level of sensory block achieved in both groups was similar. Ephedrine was required earlier ( p < 0.05) in those who received fentanyl but the total requirement of ephedrine intra-operatively was similar. Fentanyl significantly improv ed the quality of intra-operative surgical anaesthesia as none of the patients in the treatment group complained of discomfort compared with seven in the control group (p < 0.05). Similarly those in the treatme nt group had better comfort scores as evaluated by visual analogue sco re (p < 0.01). Regression of anaesthesia to T-12 took longer (184 vs 1 56 min, p < 0.05) in those who received fentanyl but this did not affe ct the total requirement of morphine in the first 24h after operation. There was no difference in the incidence of side effects in the mothe r and no adverse effects were detected in the baby. The results indica te that adding 15 mu g fentanyl to hyperbaric bupivacaine for spinal a naesthesia markedly improves intra-operative anaesthesia for Caesarean section.