Effect of dexmedetomidine combined with femoral nerve and sciatic nerve block on tourniquet application in lower limb surgery / 中国综合临床

ABSTRACT

Objective:To investigate the effect of dexmedetomidine on alleviating tourniquet pain for lower limb surgery under femoral nerve combined with sciatic nerve block and effect of systemic sedation.Methods:A prospective double-blind randomized controlled study was conducted. From January 2020 to December 2020, 80 patients who scheduled for lower extremity surgery (emergency and elective surgery) in The Second Hospital of Tangshan were randomly divided into dexmedetomidine group (group A) and control group (group B). Dexmedetomidine was used through i.v. pump in group A after successful femoral nerve and sciatic nerve block, and the same volume saline was given to group B. The changes of heart rate, mean arterial pressure (MAP), respiratory rate and oxygen saturation (SpO 2) in the two groups were observed and recorded. The main observation indexes were intraoperative sedation (Ramsay score) and tourniquet pain score (VAS score). Results:The highest Ramsay score was 4 (4,4) in group A, 2 (2,3) in group B, the difference was statistically significant ( Z=7.339, P<0.001).The lowest Ramsay score was 2 (2,2) in group A and 1 (1,1) in group B, The difference was statistically significant ( Z=7.304, P<0.001). Intraoperative VAS score was 0 (0,1) in group A and 8 (7,8) in group B, the difference was statistically significant ( Z=6.610, P<0.001). The lowest HR was (58.1±5.5) times per minute in group A and (70.0±10.6) times per minute in group B; The highest HR was (85.2±7.1) times per min in group A and (98.1±11.0) times per minute in group B ( t values were 14.453 and 4.038, respectively;and P values were <0.001 and 0.048, respectively). The lowest value of MAP was (80.3±6.0) mmHg in group A and (92.1±4.2) mmHg in group B ( t=5.009, P=0.028), there was no significant difference in the highest value of MAP, the lowest value of RR and the lowest value of SpO 2 between groups A and B (all P>0.05). Conclusion:Intravenous dexmedetomidine combined with femoral nerve and sciatic nerve block can effectively alleviate the discomfort of long-term application of lower limb tourniquet.