Combined femoral artery block and femoral nerve block reduces thigh tourniquet-induced hypertension

Abstract

Study objectiveTourniquet hypertension (TH) is thought to be caused by sympathetically mediated C-fibers in the femoral epicardium following prolonged intraoperative inflation of the tourniquet, and we hypothesized that blocking the femoral artery at the same time as a conventional femoral nerve block would reduce the incidence of TH. DesignA prospective, double-blind, randomized, controlled trial. SettingOperating room and hospital ward in the Third Hospital of Hebei Medical University. PatientsA total of 72 patients receiving high tibial osteotomy under general anesthesia were recruited from June 2022 to September 2022. InterventionsPatients were randomly assigned to receive either a classical femoral nerve block (CFNB) or a modified femoral nerve block (MFNB). Patients in the CFNB group received a 30 mL of 0.5% ropivacaine femoral nerve block and patients in the MFNB group received a 20 mL of 0.5% ropivacaine femoral nerve block combined with a 10 mL of 0.5% ropivacaine femoral artery block. MeasurementsThe primary outcome assessed was the incidence of TH. Data on intraoperative esmolol dosage, analgesic effect, complications and hemodynamics during surgery were also recorded. Main resultsIncidence of TH was significantly higher in the CFNB group compared with the MFNB group (71.88% vs 31.25%, P = 0.002). The systolic blood pressure in the CFNB group was significantly higher than that in the MFNB group at 45, 60, 75 and 90 min after tourniquet inflation (P = 0.029, P = 0.020, P = 0.009, P = 0.007). There was also a significant increase in intraoperative esmolol dosage in the CFNB group (65.63 ± 44.15 vs 22.19 ± 33.74, P < 0.001). Postoperative pain scores and patient satisfaction were not statistically significant between the two groups. ConclusionsThe present study demonstrated that modified femoral nerve block reduced intraoperative esmolol dosage and the incidence of TH.