Safety and Efficacy of Three Local Block Techniques for Diabetic Foot Surgery

Assiut University

Status: Unknown

Conditions: Anesthesia, Regional

Treatments: Procedure: sciatic nerve block; Procedure: ankle block; Drug: Bupivacaine

Study type: Interventional

Funder types: Other

Identifiers

NCT03155568

IRB00008718/ref.no2015

Details and patient eligibility

About

Diabetic patients suffering diabetic foot disease have sever comorbidities, as hypertension, ischemic heart disease, autonomic neuropathy, infections and gastric reflux all of which contribute to a high risk profile for anesthesia.

failure rate associated with ankle or popliteal nerve block may be higher than accepted, the study hypothesized that combined ankle and popliteal block may increase the success rate with no added complications.

Full description

Diabetic patients suffering diabetic foot disease regularly have sever co-morbidities, they are more liable to hypertension, ischemic heart disease, autonomic neuropathy, infections and gastric reflux all of which contribute to a high risk profile for anesthesia according to American society of anesthesiologists patients classification.

Anesthetic management for diabetic foot disease surgery is a frequent challenge and should be undertaken with a careful consideration of the anesthetic techniques available.

Hazards of general anesthesia is more likely in diabetic patients as they have low reserves to preserve against additional straining factors during general anesthesia consequently, avoiding general anesthesia in this population may be a central concern to ensure optimal peri-operative management following lower limb surgery. Neuraxial anesthesia is complicated by urinary retention, hypotension and postdural puncture headache and backache. In chronic ischemic legs, with multiple and diffuse stenosis in the leg segmental vessels, hypotension can precipitate thrombosis easily. In addition fluid loading and vasopressor administration may not be ideal methods to treat hypotension since end stage renal disease and coronary artery occlusive disease are common in these patients.

Relative to central nerve block, peripheral limb blocks are more discriminatory in their action and consequently result in less interference of bladder function and motor impairments. Also with peripheral nerve block, patients do not require postoperative fasting that help in preserving patient glycemic control. Moreover. Nerve block anesthesia has the advantages of improved postoperative pain control and it is more economical reducing hospital and associated expenses.

Ankle block alone has high failure rate and require more than usual dose to get effective. In popliteal block larger dose is needed than ankle and there is more time delay. The investigators thought to get the advantages of using local than general anesthesia with combined ankle and popliteal blocks to increase potentiation and decrease doses in diabetic foot surgery.

Aim of the study is to compare between single ankle, single popliteal and combined ankle popliteal block in diabetic patients undergoing elective foot surgery to determine block success rate, safety and efficacy to find the method of better outcome and lesser side effects.

Enrollment: 90 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• American Society of Anesthesiologists (ASA) II and III
• Co-operative
• Diabetic patients
• Scheduled for various types of elective diabetic unilateral foot operations

Exclusion criteria

• Patients suffering psychiatric neurological or neuromuscular disorders.
• Allergy to local anesthetics used.
• Infection at the block site.
• Sever renal and hepatic impairment.
• Patients receiving chronic analgesic therapy.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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90 participants in 3 patient groups

sciatic nerve block

Active Comparator group

Description:

ultrasound guided sciatic nerve block by injecting 30ml of 0.5% bupivacaine and visualized circumferentially spreading around the sciatic nerve

Treatment:

Procedure: sciatic nerve block

Drug: Bupivacaine

ankle block

Active Comparator group

Description:

ankle block performed by injecting 20 ml of 0.5% bupivacaine in equal amounts around the five major nerves supplying the foot

Treatment:

Procedure: ankle block

Drug: Bupivacaine

combined popliteal and ankle block

Active Comparator group

Description:

combined block performed by the use of 20 ml of 0.25% bupivacaine for sciatic nerve block followed by the ankle block with use of 20 ml of 0.5% bupivacaine both in the same manner as other two groups.

Treatment:

Procedure: sciatic nerve block

Procedure: ankle block

Drug: Bupivacaine