Sequential intrathecal injection of fentanyl and hyperbaric bupivacaine at different rates: does it make a difference? A randomized controlled trial

Abstract

Background Previous studies have shown that sequential intrathecal injection of fentanyl and hyperbaric bupivacaine for cesarean section (CS) anesthesia provides a superior anesthetic effect than use of bupivacaine alone, and prolongs postoperative analgesia. Herein, we investigated whether rapid intrathecal injection of fentanyl followed by slow injection of hyperbaric bupivacaine affects the duration of postoperative analgesia, the effectiveness of anesthesia, and hemodynamic status. Methods Fifty-six parturients with American Society of Anesthesiologists physical status I or II, aged 18–40 years, and scheduled to undergo elective CS were randomly assigned to 2 groups of 28 patients each. The normal sequential group received sequential intrathecal injections of fentanyl and hyperbaric bupivacaine at the same rate, each with a 5 ml syringe. The rapid sequential group received a rapid intrathecal injection of fentanyl with an insulin syringe, followed by a slow injection of hyperbaric bupivacaine with a 5 ml syringe. The onset of sensory block, the timing of the first rescue analgesia, the doses of rescue analgesics, the degree of postoperative pain, the onset and duration of motor block, the incidence and duration of hypotension, and spinal anesthesia-related complications were recorded. Results While both approaches had comparable spinal anesthesia-related complications, incidence and duration of hypotension, and doses of ephedrine, the rapid sequential group exhibited a more rapid onset of sensory block, a higher sensory level, and more prolonged postoperative analgesia. Conclusions Rapid sequential injection of fentanyl and hyperbaric bupivacaine produced superior anesthesia and more prolonged postoperative analgesia than sequential injections of both at the same rate.

Comparison of Premixed with Sequential Administration of Intrathecal Morphine and Hyperbaric Bupivacaine for Lower Segment Caesarean Section

“…et al study who found no difference in regression time to bromage 0 between premixed and sequential groups. [4] [13] We observed that in our study, clinically maximum analgesia lasted in premixed group after the surgery followed by sequential groups but statistically it was nonsignificant. However Hussien RM et al concluded that sequential injection of IT fentanyl when given rapidly, it prolongs postoperative analgesia.…”

“…When fentanyl was injected in a rapid sequential manner, resulted in increased somatic analgesia with no effect on degree or level of motor block, induced by LA. [13] In our study regression time to sensory block T10 was found statistically significant between the groups (p=.002), but on comparison between premixed and sequential group no statistically significant difference was seen. Hussien RM et.al.and Desai S et al also reported similar result.…”

“…Hussien RM et.al.and Desai S et al also reported similar result. [4] [13] Resolution time to motor block (Bromage 0) was comparable to each other, and it was statistically insignificant (p>0.005). Our study correlated with Desai S. et al and Hussien RM.…”

“…However Hussien RM et al concluded that sequential injection of IT fentanyl when given rapidly, it prolongs postoperative analgesia. [13] Ummenhofer WC.et al found that morphine injected intrathecally results in adequate and long lasting analgesia due to its hydrophilicity, decreased systemic absorption, cephalad spread in cerebrospinal fluid and slow rate of clearance from the opioid receptors. [14] Hemodynamic parameters (SBP, DBP, MABP) showed no statistically significant difference in all the three groups when compared with base line.…”

“…Hussien RM et.al.and Desai S et al also reported similar result. [4] [13] Peritoneal traction and exteriorization of the uterus during a cesarean section and predominant vagal effect can lead to nausea and vomiting by triggering the vomiting center. [15] Postoperative hypotension was statistically significant (p=0.026).…”