Hyperbaric articaine with or without fentanyl in spinal anaesthesia: patient and observer blinded comparison

The rapid and short-acting local anaesthetic articaine is a feasible spinal anaesthetic for day-case open inguinal herniorrhaphy (OIH). We hypothesised that similarly to other spinal local anaesthetics, the addition of fentanyl may prolong articaine spinal analgesia without prolonging motor block.

We performed a randomised, controlled study in 100 adult patients undergoing OIH. Spinal anaesthesia was induced by injecting hyperbaric articaine 72 mg with (Group A + F) or without (Group A) fentanyl 10 μg with the patient in lateral decubitus position. The distribution of sensory block was tested using pinprick and controlled by tilting the operating table 10 up or down. Motor block testing was based on the patient's ability to flex knees and ankles. Rescue analgesic was intravenous (i.v.) fentanyl. Pain scores were registered, and i.v. paracetamol 1 g was given as the first post-operative analgesic.

There were no differences (A + F vs. A) in the maximum median extension of the sensory block (T5 vs. T5), mean duration of sensory block ≥ T10 (76 min vs. 73 min), or total duration of sensory (146 min vs. 146 min) or motor block (99 min vs. 107 min). Fewer patients in Group A + F needed fentanyl (5 vs. 14, P < 0.05) perioperatively or paracetamol (3 vs. 18, P < 0.001) post-operatively.

Fentanyl 10 μg added to spinal hyperbaric articaine improved analgesia and reduced analgesic consumption during and after OIH. Fentanyl did not prolong motor block or delay recovery.