A Comparative Study of Premixed Versus Succedent Administration of Dexmedetomidine and Bupivacaine in the Subarachnoid Block for Infraumbilical Surgeries.

BACKGROUND

The suggested method for infraumbilical surgeries is spinal anaesthesia. Postoperative pain management is challenging, as spinal anaesthesia utilising solely local anaesthetics provides only a short analgesic effect. Therefore, early pain relief is necessary in the postoperative period.

AIMS AND

OBJECTIVES

In this study, dexmedetomidine and bupivacaine were administered either premixed in a single syringe or sequentially in separate syringes for subarachnoid block in infraumbilical surgeries across different study groups. We compared the sensory and motor block characteristics, intra-operative hemodynamics, postoperative pain relief, and any side-effects in patients undergoing lower abdominal surgeries. The effect of administering dexmedetomidine before bupivacaine heavy and vice versa on these parameters was also assessed.

METHODOLOGY: The study involved 120 patients, as classified by the "American Society of Anaesthesiologists", physical status I and II, all scheduled for lower abdominal procedures (gynaecological, urological, orthopaedic, and other lower abdominal procedures) under spinal anaesthesia. Three groups of patients were randomly selected: Group A received two intrathecal injections. The first injection consisted of 5 mcg of dexmedetomidine diluted in preservative-free normal saline (0.5 mL), followed by 12.5 mg of 0.5% heavy bupivacaine (2.5 mL), both in separate 3 mL syringes. In Group B, participants received intrathecal injections of premixed solution divided into two separate 3 mL syringes, one with 2.5 mL and the other with 0.5 mL of premixed solution. A premixed solution (3 mL) was made with 5 mcg of dexmedetomidine diluted in 0.5 mL of preservative-free normal saline and 12.5 mg of 0.5% heavy bupivacaine (2.5 mL). Group C participants were given two consecutive intrathecal injections, first 12.5 mg of 0.5% heavy bupivacaine (2.5 mL) using a 3 mL syringe and 5 mcg of dexmedetomidine diluted in preservative-free normal saline (0.5 mL) in a second 3 mL syringe. Statistical analysis has been performed utilizing Statistical Product and Service Solutions (SPSS, version 20; IBM SPSS Statistics for Windows, Armonk, NY).

RESULTS

The earliest average onset time for sensory block has been observed in Group A, which was monitored by Groups B and C. Group C had the lowest average onset time for motor block, followed by Groups A and B. Groups A and C experienced sensory and motor blockage for more extended periods. Compared to Groups A and C, Group B patients have a greater incidence of bradycardia as well as hypotension.

CONCLUSIONS

The research illustrates that, in contrast to spinal anaesthesia with a premixed dosage of hyperbaric bupivacaine and dexmedetomidine, sequential intrathecal injection produces a longer sensory and motor block with a quicker onset.