Efficacy of coadministration of calcitonin and hyperbaric bupivacaine in spinal anesthesia for unilateral open inguinal hernia repair in tramadol abuse patients: a randomized controlled trial

Abstract

Abstract Background Tramadol abuse is a socio-economic problem in low resource income communities and was proposed as a cause of failed spinal anesthesia (SA). The research team evaluated coadministration of a single-shot hyperbaric bupivacaine with either intrathecal (IT) or intravenous (IV) calcitonin (CAL) for SA regarding postoperative pain control characteristics and incidence of failed SA in tramadol-abuse patients undergoing unilateral open inguinal hernia repair in a randomized controlled trial. Methods Ninety Egyptian patients were randomized into three equal groups; IT-CAL, IV-CAL and control (C) Groups. All patients received SA, 100 IU calcitonin in IT-CAL Group, 100 IU calcitonin diluted in 10 ml IV normal saline solution (NSS) in IV-CAL Group and NSS in C-Group. The total amount of morphine (rescue analgesic) consumed 24 h following surgery was the primary outcome measure. Secondary outcomes included, incidence of failed SA, time to first request for analgesia, the duration of sensory blockade (duration of analgesia), VAS scores at rest and on movement, CRP level, patient satisfaction with postoperative (PO) pain management and side effects. Results Out of 30 randomized patients in each group, failed SA occurred in only one patient in IT-CAL Group while occurred in 8 and 9 patients in IV-CAL and C groups, respectively (P = 0.018). Among the cases with successful SA, the total morphine consumption (19.1 ± 2.9 mg/24h in IT-Cal Group), serum CRP levels and area under the curve of pain scores perceived over 24 h following surgery were significantly lower in IT-Cal Group among the three groups (P < 0.001). Incidence of side effects was comparable between study groups (P > 0.05). Conclusions One hundred IU intrathecal calcitonin administration as an adjuvant to hyperbaric bupivacaine was associated with lower total morphine consumption, attenuated stress response and lower incidence of failed spinal anesthesia in tramadol abuse patients undergoing unilateral open inguinal hernia repair when compared with intravenous calcitonin. Trial registration ClinicalTrials.gov Identifier: NCT04445857. IRB: 6379.