A comparison of articaine and fentanyl-supplemented articaine for hemodialysis fistula creation under ultrasound-guided axillary block.

The aim of this prospective randomized, double-blinded study was to evaluate the effect of fentanyl addition to articaine on the duration of sensory as well as motor blocks, and the duration of analgesia during hemodialysis fistula creation under ultrasound-guided axillary block. Fifty patients were randomly allocated to two groups, an articaine group (A), receiving 40 mL of articaine HCI (20 mg/mL) with 2 mL of isotonic sodium chloride solution, and an articaine-fentanyl group (AF), receiving 40 mL of articaine HCI (20 mg/mL) with 2 mL (100 µg) of fentanyl. The onset as well as the duration of sensory and motor blocks, the time necessary for first analgesic administration, the hemodynamic parameters, and the side effects were recorded. Three patients in Group A and two patients in Group AF due to incomplete block were excluded from the study. The duration of sensory and motor blocks was significantly longer in the AF group than in the A group. The first time for analgesic need was also significantly longer in group AF (363 ± 134 min) than in group A (244 ± 84 min) (p = 0.001). The addition of fentanyl did not improve the onset of sensory and motor block times. Hemodynamic parameters were similar in the two groups. In conclusion, the addition of fentanyl to articaine in axillary block prolongs the duration of sensory and motor blocks, as well as the time of first analgesic requirement.