Nerve Block Extends Nerve Function Recovery in Patients with Diabetic Foot Ulcers

Area of Science:

• Anesthesiology
• Diabetology
• Neurology

Background:

• Peripheral neuropathy in diabetes mellitus (DM) is associated with elevated nerve stimulation thresholds.
• Specific nerve stimulation thresholds and block recovery in diabetic foot patients are not well-defined.

Purpose of the Study:

• To determine the minimum stimulation thresholds of the femoral and sciatic nerves in diabetic foot patients.
• To assess the duration of nerve block and nerve function recovery in this population.

Main Methods:

• Prospective study of 83 diabetic foot patients and 48 controls (age 50-80) undergoing distal lower limb surgery.
• Ultrasound-guided femoral and popliteal sciatic nerve blocks using ropivacaine were performed.
• Minimum electrical current for motor response in femoral and sciatic nerves was measured.

Main Results:

• Diabetic foot patients showed significantly higher stimulation thresholds for femoral and sciatic nerves (P < 0.01).
• Femoral and sciatic sensory and motor blocks were substantially longer in duration for diabetic foot patients (P < 0.01).
• Nerve injury occurred in 4.8% of diabetic foot patients.

Conclusions:

• Diabetic foot patients require higher stimulus to elicit nerve response.
• Ropivacaine nerve blocks exhibit prolonged duration and delayed recovery in diabetic foot patients.
• Higher incidence of nerve injury noted in diabetic foot patients.