Comparison of analgesic efficacy of perineural dexamethasone in rectus sheath block and intravenous dexamethasone with levobupivacaine in bilateral rectus sheath block for patients undergoing midline abdominal surgery: a randomized controlled trial

Abstract

Abstract Background Dexamethasone is used in regional analgesia to prolong the duration of analgesia and anaesthesia. The perineural and intravenous (IV) dexamethasone in fascial plane block have conflicting results. The study aimed to compare analgesic efficacy of perineurally and intravenously dexamethasone in rectus sheath block (RSB). This prospective, double-blinded, randomized control study was conducted in 105 patients, equally divided in three groups. All the patients received ultrasound-guided RSB block with 20 ml of 0.25% levobupivacaine on each side. Additionally, in group A, 1-ml normal saline (NS) on each side in RSB block and 2-ml NS IV; in group B, 4-mg dexamethasone on each side in RSB block and 2-ml NS IV; and in group C, 1-ml NS on each side in RSB block and 8-mg dexamethasone IV. The primary objective of the study was the duration of analgesia, and secondary objectives were total morphine consumption in the first 24 h, numeric rating scale (NRS) scores at rest and on cough, complications and patient’s satisfaction score. Results The duration of analgesia was maximum in group B (935.91 ± 121.82 min) and then in group C (730.31 ± 129.64 min) and group A (418.34 ± 29.22 min) (P < 0.0001). The morphine consumption and mean NRS score (at rest and cough) were lowest in group B and then group C and group A (P < 0.0001). Conclusions The perineural dexamethasone as an adjuvant to levobupivacaine prolongs the duration of analgesia with decreased analgesic requirements compared to intravenous dexamethasone in bilateral RSB in patients undergoing midline laparotomy surgery.