Dexmedetomidine + Fentanyl provides the longest duration of labor analgesia when compared to  Dexmedetomidine alone and Fentanyl alone.

The aim was to explore the analgesic effects of intrathecally administering Fentanyl, Dexmedetomidine, and a combination of both during active labor. Additionally, the research aimed to assess the potential side effects of Fentanyl and Dexmedetomidine on both the mother and the newborn.

Conducted as a prospective randomized controlled trial over a 7-year period, the study involved 90 parturients. The recruited subjects were randomly assigned to three groups based on the labor analgesic drugs they received,

Group F: Intrathecal Fentanyl 20 µg in1 mL normal saline

Group D: Intrathecal Dexmedetomidine 10 µg in 1mL normal saline

Group F + D: Intrathecal 5 µg Dexmedetomidine plus 10 µg Fentanyl in 1 mL normal saline

The results were subjected to statistical analysis.

Dexmedetomidine alone (Group D), and the combination of Dexmedetomidine and Fentanyl (Group F+D), were found to provide adequate labor analgesia comparable to Fentanyl alone (Group F), as indicated by equivalent minimum Visual Analog Scale (VAS) scores (below 2) across all three groups, as shown in Table 1:

The mean duration of analgesia was highest in the Group F+D when compared to the other two groups,  as shown in Table 2:

Notably, pruritus emerged as a significant side effect of Fentanyl, with a total of 6 incidents out of 30 parturients, a frequency significantly higher than both Dexmedetomidine alone and Dexmedetomidine + Fentanyl.

The combination of Dexmedetomidine and Fentanyl resulted in the longest duration of analgesia among the three groups, suggesting a potential synergistic effect of these drugs without adversely affecting maternal hemodynamics and neonatal outcomes.