Analgesic effects of dexmedetomidine combined with ropivacaine in continuous femoral nerve block after total knee arethroplasty

ObjectiveTo investigate the analgesic effects and side effects of dexmetomidine combined with ropivacaine in continuous femoral nerve block after total knee arthroplasty.

MethodsSixty patients with continuous femoral nerve block analgesia after total knee arthroplasty were randomly divided into the control group(group C, 30 cases) and dexmdetomidine group(group D, 30 cases).The analgesic solution in group C and group D were 0.2% ropivacaine and 0.2% ropivacaine combined with 0.1μg·kg^-1·h^-1.dexmdetomidine, respectively.The scores of resting pain, motor pain and sedation in two groups were recorded before operation and after 3, 6, 12, 24 and 48h of operation.The scores of quadriceps femoris muscle strength were tested before surgery and after 24h and 48 h of surgery, and the bradycardia, hypotension and excessive sedation of adverse reactions were observed in two groups.

ResultsThe NRS scores of rest pain and motor pain in group D were significantly lower than those in group C at 6, 12, 24 and 48 hours after surgery(P < 0.05 to P < 0.01).The sedation scores in group D were higher than that in group C at all time-points after surgery(P < 0.01).The incidence rates of hypotension and bradycardia in group D were significantly higher than those in group C(P < 0.05).

ConclusionsThe dexmetomidine combined with ropivacaine in continuous femoral nerve block can enhance the analgesic effects and sedation effects, and dose not affect the muscle strength of quadriceps femoris.The hypotension and bradycardia of adverse reactions need to be prevented.