Efficacy of Gastrocnemius Plane Block for Foot and Ankle Surgery

• GPB Group : This group will receive ultrasound-guided Gastrocnemius plane block with 30 mL bupivacaine (0.25%) (Drug): o In lateral position, a high frequency US (Siemens ACUSON X300 Ultrasound System) linear probe (8-12 mhz) will be placed in the popliteal fossa facing the operator. Scanning continue towards the foot, and the gastrocnemius will appear. As the scanning progresses towards the caput fibulae, the soleus gradually becomes visible. Once Gastrosoleus Interfascial Plane is identified, a needle advanced by consultant anesthesiologists who had experience in regional anesthesia in a lateral-to-medial direction into the lower surface of the gastrocnemius (between the gastrocnemius and the soleus). Subsequently, 20 mL bupivacaine (0.25%) will be injected to separate the fascias of the two muscles, allowing the local anaesthetic to diffuse around the tibial nerve through the fascial gap. The needle is then withdrawn to the upper surface of the gastrocnemius, and 10 mL bupivacaine (0.25%) will be injected into the upper surface (between gastrocnemius and deep subcutaneous fascia) to block
• SAB (Drug): * Patients will receive SAB using 25g spinal needle in the lateral position with rapid crystalloid co-loading. Fifteen milligrams of hyperbaric bupivacaine will be administered at L3-L4 or at L4-L5 interspace in addition to 25 mcg fentanyl. The dose will be reduced to 10 mg in patients aged above 60 years. * SAB will be considered successful when a bilateral block is confirmed at T12. The block success will be assessed by loss of cold (cold ice) and pain (a 23-gauge needle) sensations. If spinal anaesthesia fails, the patient will receive general anaesthesia and will be excluded from the study.

Primary outcomes

• Time to first postoperative analgesic request [24 hours]: Time to first postoperative analgesic request

Secondary outcomes

• Visual analogue pain score (VAS) [24 hours]: Visual analogue pain score (VAS) at rest (static), and on movement (dynamic) at 2, 4, 6, 12, 18, and 24 hours postoperatively
• Postoperative assessment of sensory and motor function [24 hours]: Assessment of sensory block: Sensory block will be assessed using a pinprick test with a blunt 22-gauge needle along dermatomes relevant to the surgery. The degree of sensory loss will be graded as follows: * Grade 0: Normal sensation to pinprick * Grade 1: Decreased but present sensation to pinprick (hypoalgesia) * Grade 2: Complete loss of sensation to pinprick (analgesia)
• Time to first postoperative analgesic request [24 hours]: Time to first postoperative analgesic request
• Total morphine requirements [24 hours]: Total morphine requirements 24 hours postoperatively.
• Time to early mobilization [24 hours]: Time to early mobilization: First bedtime helps to judge the effect of the nerve block
• Incidence of complications related to the blocks [24 hours]: Incidence of complications related to the blocks as hematoma or Toxicity
• Incidence of postoperative nausea and vomiting [24 hours]: Incidence of postoperative nausea and vomiting
• Postoperative assessment of motor function [24 hours]: Assessment of motor block: using the Modified Bromage score, which will be evaluated to assess the motor block as follows: * Bromage 0: full flexion of the knee and feet. * Bromage 1: just able to move the knee * Bromage 2: able to move the feet. * Bromage 3: unable to move the knees and feet

Sex: All, ages: 18 Years to 65 Years

Inclusion Criteria:

* Elective foot and ankle surgeries, including procedures for fractures of the fibula, tibia-fibula, metatarsal, or calcaneus, as well as corrective surgery for hallux valgus;
* Aged 18- 65 years
* BMI 18-28 kg/m2
* ASA Ⅰ-Ⅲ.

Exclusion Criteria:

* Puncture site infection
* Abnormal coagulation function: international normalized ratio (INR) > 1.5; platelet count < 50×109/L
* Local anaesthesia allergy
* Unstable coronary syndrome (e.g., recent myocardial infarction within 3 months);
* Severe cardiopulmonary disease: heart failure (NYHA, functional class III or IV)
* Severe pulmonary disease (e.g., chronic obstructive pulmonary disease with FEV1 < 50% of predicted, or requiring home oxygen therapy)
* Liver insufficiency: liver disease (Child- Pugh class B or C) or elevated liver enzymes (ALT or AST) > 3 times the upper limit of normal;
* Renal insufficiency renal impairment (estimated glomerular filtration rate, eGFR<30 mL/min/1.73m2) or requiring renal replacement therapy
* Long-term preoperative use of sedative and analgesic drugs;
* Communication disorders
* History of chronic pain.
* Operative time > 3 h.

• Nagy Malak, MD, Principal investigator, Cairo University