Hemodynamic changes during spinal anesthesia for elective cesarean section with hyperbaric bupivacaine : effect of volume and concentration

Abstract EN

Background: Spinal anesthesia for cesarean section with hyperbaric Bupivacaine is widely used.

The course of the procedure is frequently troubled by hemodynamic instability that is determined by the level of spinal block and this in turn depends on the spread of the local anesthetic within the CSF.

By fixing the dose of the local anesthetic any increase in its volume leads to a decrease in its concentration because these factor are closely related to each other and they can a^؛ct the spread of the local anesthetic.

Objective: To compare between large volume but lower concentration (4 ml of 0.25%) and small volume but higher concentration (2 ml of 0.5% ) of hyperbaric Bupivacaine solutions used for spinal anesthesia for elective cesarean section in respect to hemodynamic changes.

Method: A clinical interventional study was Performed at Al-Zahra'a Teaching Hospital (^af ) from 18th Jun.-18th Jul.

2013.

Forty patients scheduled for elective cesarean section were randomly selected and randomly divided into two equal groups (A and B).

Both groups received hyperbaric Bupivacaine via intrathecal route, group (A) received 4 ml of 0.25% solution while group (B) received 2 ml of 0.5% solution.

Hemodynamic variables (blood pressure and heart rate) were recorded throughout the time of anesthesia.

Data was analyzed by using SPSS version 20.

Results: There was no significant deference in the incidence of hypotension (P value=1.0) between the two groups while the incidence of bradycardia was equal between the two groups (10%) but there was a need for significantly higher average dose of Ephedrine that was used to treat hypotension in group (A) than in group (B) (P value=0.49%) reflecting more severe hypotension in group (A) than group (B).

Conclusion: we conclude that the volume factor has more influence than the concentration on blood pressure with regard to hyperbaric intrathecal Bupivacaine solutions used for elective cesarean section.

Recommendation: the use of smaller volume but higher concentration of intrathecal Bupivacaine is advisable in elective cesarean section.