Randomised comparison of hyperbaric articaine and hyperbaric low-dose bupivacaine along with fentanyl in spinal anaesthesia for day-case inguinal herniorrhaphy

Abstract

Low-dose mixture of hyperbaric bupivacaine and fentanyl is commonly used in day-case spinal anaesthesia. Using hyperbaric articaine, the onset may be faster and duration more predictable than with bupivacaine-fentanyl. We compared these two spinal anaesthetics for inguinal herniorrhaphy. Adult patients were randomised to spinal anaesthesia with hyperbaric articaine 84 mg (group A, n = 40) or hyperbaric bupivacaine 7 mg along with fentanyl 10 μg (group B+F, n = 40). A blinded observer tested the block characteristics. Aiming at sensory block spread to T10 dermatome, the operating table was tilted head-end up or down 10° (once or twice), as required. Postoperative telephone interviews were performed. All patients in group A had a sensory block to T10 in a median time of 4 (range 2-20) min. In group B+F, the median onset time of T10 analgesia was 10 (2-30) min (P < 0.001), but T10 analgesia was not reached in seven of 40 B+F patients. A head-up tilt was needed in 37 of 40 group A patients to prevent from too extensive cephalad spread of block, and 34 of 40 group B+F patients needed a head-down tilt to enhance cephalad spread of analgesia. To treat hypotension, 6.4 mg of ephedrine was required, on average, in group A and 1.8 = mg in group B+F (P = 0.01). Median time to recovery from sensory block was significantly shorter in group A (2.5 h) than in group B+F (3 h; P = 0.002). General anaesthesia was needed in three patients (group A, two patients: sensory block too short; group B+F, one patient: sensory block too limited). Hyperbaric articaine leads to faster onset of block and faster recovery than bupivacaine along with fentanyl. Hypotension is more common with articaine. The onset and extension of the spinal block are unpredictable when using these techniques.