bradycardia and severe bispectral index drop following femoral nerve block by dexmedetomidine due to accidental vascular puncture: a case report

a 25-year-old afghan male was presented to the emergency department with femoral shaft fracture following fall from the height. the patient was subjected to femoral nerve block and general anesthesia. first try for performing nerve block led to vascular puncture. therefore, the needle was removed and re-inserted 1 cm lateral to first puncture site and dex injected slowly with aspiration check after every 5 ml to avoid intravascular injection. immediately after injection, heart rate dropped to 40, blood pressure decreased to 85/50 mmhg and the bis dropped to 30. because of not spontaneous resolving the situation atropine and ephedrine were ordered that resulted to regain hemodynamic stability. it is likely that vascular puncture during peripheral nerve block can lead to some adverse events that need to be monitored precisely.