Effect of local anesthetic temperature on vasopressor usage in spinal anesthesia for elective cesarean section

Abstract

Hypotension following spinal anesthesia in patients undergoing cesarean section is a common occurrence in medical practice and requires vasopressors for treatment to prevent severe complications. This study aimed to compare the use of heavy bupivacaine at 25°C and 37°C in terms of vasopressor requirements for treating hypotension, specifically to determine if heavy bupivacaine at 25°C would require less vasopressor usage. This was a prospective randomized control trial conducted in the operating room at Pak Kret Hospital from October 2022 to September 2023. The study included 60 ASA I-II pregnant women with singleton pregnancies scheduled for elective cesarean section. They were divided into two groups: the control group (H1, n=30) received spinal anesthesia with 0.5% heavy bupivacaine 10 mg with morphine 0.2 mg (total volume 2.2 mL) at 25°C, and the experimental group (H2, n=30) received the same medication at 37°C. The results showed no significant differences in general demographic data between the two groups. After anesthesia administration, the time from spinal block to onset of hypotension and vasopressor use showed that the H1 group first experienced hypotension and received medication at 3 minutes, while the H2 group experienced hypotension earlier and received medication from the first minute post-spinal block. In the H1 group, 15 patients experienced hypotension and received vasopressor (ephedrine) with an average dose of 28.67 mg. The H2 group had more patients (18) experiencing hypotension and requiring ephedrine, but the average dose was lower at 21.33 mg. However, statistical analysis showed no significant difference in medication dosage between the two groups.