Introduction: Study compare spinal anesthesia using hyperbaric bupivacine
(0.5% - 0.75%) between fixed dose and height adjusted dose during elective
cesarean section. Methods: Hundred parturients who had given their consent
and were scheduled for elective cesarean section under spinal anesthesia, were
divided into four groups—first group received 0.5% hyperbaric bupivacine
fixed dose, the second group received 0.5% hyperbaric bupivacine in a dose
adjusted to the height, the third received 0.75% hyperbaric bupivacine fixed
dose, the fourth group received 0.75% hyperbaric bupivacine in a dose adjusted
to height. The anesthesia onset time, haemodynamic changes, side effects
and fetal outcome observed. Results: spinal block provide excellent surgical
anesthesia in all patients. Anesthesia onset time is longer in adjusted
than fixed groups, in 0.5% (5 ± 0.816 vs. 3.84 ± 0.746) (P < 0.001) and in
0.75% (3.76 ± 0.778 vs. 3.28 ± 0.741) (P 0.03), the motor block was less dense
and of short duration in adjusted groups with decrease in the length of
post-anesthetic care unit stay. There is decrease in incidence and severity of
hypotention with decrease in total dose of vasopressors used in adjusted than
fixed dose groups in 0.5% ephedrine (10 ± 6.123 vs. 19.6 ± 12) mg (p 0.008)
and in 0.75% phenylephrine (0.268 ± 0.07 vs. 0.596 ± 0.2) mg (P < 0.004),
Nausea and vomiting were more frequent in fixed dose groups. Conclusion:
Adjusting dose of hyperbaric bupivacine (0.5% - 0.75%) to patient’s height,
decreases the dose of bupivacine in use, it also provide adequate anesthesia
for elective cesarean section with decrease the use of vasopressors, the incidence
and severity of maternal hypotention also markedly reduced