The Difference in Duration of Sciatic Nerve Block Between Diabetic and Non-diabetic Patients

The Difference in Duration of Sciatic Nerve Block Between Diabetic and Non-diabetic Patients

This study aims to compare the sensory and motor block duration and the incidence of nerve injury after sciatic nerve block between diabetic and non-diabetic patients, and screen for the factors that may affect the block recovery.

This is an observational study. All participants who experienced unilateral lower limb surgery and received an ultrasound-guided (nerve stimulator assisted) subgluteal sciatic nerve block with 0.75% ropivacaine 20ml in Peking Union Medical College Hospital were selected. They were further assigned to either diabetic group or non-diabetic group according to their medical history (primary exposure). The primary end point was the sensory and motor block duration. These durations in terms of sensory and motor blocks of sciatic nerve(dorsal side, plantar side) were assessed at baseline, every 2 hours in 48 hours after the block (except for the second night). In addition, the associations between fasting blood glucose, glycosylated hemoglobin (hemoglobin A1c, HbA1c) and the degree of diabetic retinopathy and the durations of sensory and motor block were also examined. This is not a intervention study, because we will examine the outcomes between diabetic or non-diabetic patients.

Inclusion Criteria:

• American Society of Anesthesiologists :I-III;
• Age>=18 years;
• Undergo unilateral lower limb surgery;
• Sign consent form.

Exclusion Criteria:

• Refuse regional Anesthesia;
• Thresh of sensory >10g;
• Dyskinesia;
• Bleeding disorder;
• Regional skin infection;
• Regional drug allergy;
• Renal disfunction;
• Incompliant to study;
• Drug abuse.