SOFT Block Versus Spinal Anesthesia in Patientsusing Ilizarov External Fixator
Condition: Pain, Acute
MeSH terms: Acute Pain
Study type: Interventional

Summary: 
      Peripheral nerve block is an ideal choice for lower limb surgery because of the peripheral
      site of the surgical procedure and the ability to block pain pathways at multiple levels. On
      the contrary to other anesthetic techniques, as spinal or general anesthesia, properly
      performed peripheral nerve blocks bypass adverse events as hemodynamic instability and
      respiratory complications, properly treat post-operative pain leading to early hospital
      discharge. Additional advantages of peripheral nerve blocks are that they can be used in
      patients receiving anti-coagulants or lumbosacral disease in addition to avoidance of airway
      instrumentation.

      Recently, there has been a significant interest in regional anesthesia and peripheral nerve
      blockade. This is facilitated by a significant advance of the research in this field and
      availability of better equipment facilitating regional anesthesia.The aim of this study was
      to assess the efficacy and safety of SOFT block (sciatic-obturator-femoral nerve block
      technique) in comparison with spinal anesthesia in patients undergoing surgery for fixation
      of open tibial fractures using Ilizarov external fixator.
    

Detailed description: 
      After the approval of medical ethical committee of Ain Shams University, this prospective
      parallel group double blinded study will be conducted over 60 patients between the age of
      35-57 years old, ASA physical status I and II, scheduled for fixation of open tibial
      fractures using iIlizarov external fixator. at Ain Shams University hospitals in 2018-2019,
      After written informed consent is obtained.

      Refusal to participate, inability to communicate with the investigators or hospital staff,
      obesity (body mass index>40 kg/m2), patients undergoing bilateral surgery, patients with
      coagulopathies ,renal insufficiency (creatinine>1.5 mg/dL), American Society of Anesthesia
      (ASA) III-IV, patients with any contraindication to regional anesthesia , patients with
      unstable vital data and patients with head or chest trauma will be excluded.

      Preanesthetic check will be done at night of surgery. After an intravenous (IV) cannula will
      be secured , and midazolam 0.05 mg/kg i.v. will be given to all patients before transfer to
      the operating room where standard monitoring devices as ECG,Non invasive blood pressure and
      pulse oximetry will be placed. Then, patients will be randomly allocated by sealed envelope
      technique to receive either spinal anesthesia or SOFT block. In spinal anesthesia group,
      patients will receive spinal anesthesia with hyperbaric bupivacaine 0.5% (7.5-10mg). This
      will be administered via a 25-G spinal needle at L4-L5 or L3-L4 with the patient in the
      sitting position under complete aseptic conditions.

      In SOFT group, patients will receive SOFT block where patients will be positioned in supine
      position,under aseptic conditions, a linear US probe will be placed on the inguinal crease to
      show the femoral nerve and vessels. Using an in-plane technique, a 12-cm stimulating block
      needle will be introduced medial to the femoral vein and advanced 1-3 cm below and parallel
      to the skin. Then, It will be redirected toward the fibres of the femoral nerve, where 15 mL
      of bupivacaine 0.25% will be injected. To block the obturator nerve, the probe will be
      shifted medially, superior to the needle, and directed cranially to identify the pectineus
      muscle . The needle will be then withdrawn to the subcutaneous tissue and redirected using an
      out-of-plane technique toward the deep surface of the pectineus, where 10 mL of bupivacaine
      0.25%will be injected.[4 ] To locate the sciatic nerve, we will use the curvilinear probe,
      directed it inferior to the needle, and tilted the probe to get the clearest image of the
      sciatic nerve.The needle will be inserted then withdrawn subcutaneously and directed by an
      in-plane technique toward the sciatic nerve deep to the inferior border of the quadratus
      femoris muscle. Then 20 mL of bupivacaine 0.25% will be injected after needle elicited muscle
      twitches using 1 mA current.

      Sensory level will be evaluated by loss of pinprick sensation (20-gauge hypodermic needle).

      Haemodynamic variables will be recorded every 5 min after block performance until the end of
      surgery. Hypotension will be defined as a decrease in systolic arterial blood pressure by 30%
      or more from baseline values, and it will be initially treated with 200 ml IV infusion of
      Ringer's lactate solution; if this proved to be ineffective, an IV bolus of phenylephrine
      (40-50 mcg) will be given. Bradycardia is defined as heart rate decrease below 45 bpm, and it
      was treated with 0.5 mg IV atropine.

      Sensory block(loss of pinprick sensation at T12 in the Spinal group, or in the femoral,
      obturator and sciatic nerves distribution in the SOFT group). The quality of the block will
      be judged according to the need for supplementary IV analgesics and sedation: adequate nerve
      block = neither sedation nor analgesics required to complete surgery; inadequate nerve block
      = need for rescue dose of analgesic (100 mg IV bolus of ketamine) or sedation (3mg IV
      midazolam) will be required to complete surgery; failed nerve block so general anesthesia
      will be required to complete surgery.

      After completion of surgery, patients will be transferred to the post-anesthesia care unit
      (PACU). Intravenous pethidine (50 mg) will be given as rescue analgesic as needed. Primary
      endpoint is the time from the end of local anaesthetic injection to complete resolution of
      sensory block. The secondary endpoints include patient satisfaction, (on a numerical rating
      scale), the adverse events as back pain, postural -puncture headache , vomiting, adverse
      events of systemic toxicity from local anesthetic as seizures and cardiovascular collapse,
      persistent parasthesia observed within 48 hours after the block and failure rate of the block
      will be recorded.

      In case of failure of the block or incidence of seizures resulting from local anesthetic
      toxicity , we will convert to general anesthesia.

      In case of cardiovascular collapse, support the patient with intravenous fluids and
      vasopressors as required so in these cases patients will be excluded from the study.
    

Intervention name(s): SOFT block group; spinal anesthesia group
Intervention type(s): Device; Device
Intervention description(s): needle will be introduced medial to the femoral vein and 3 cm below the skin where 15 mL of bupivacaine 0.25% injected. the obturator nerve, the probe shifted medially, superior to the needle, and directed cranially to the pectineus muscle . Needle withdrawn to the subcutaneous tissue and redirected using out-of-plane toward the deep surface of pectineus, 10 mL of bupivacaine 0.25%will be injected. The sciatic nerve, we use the curvilinear probe, inferior to the needle, and tilted the probe to get the clearest image of the sciatic nerve.The needle will be inserted then withdrawn subcutaneously and directed by an in-plane toward the sciatic nerve deep to the inferior border of the quadratus femoris muscle.20 mL of bupivacaine 0.25% will be injected; patients will receive spinal anesthesia with hyperbaric bupivacaine 0.5% (7.5-10mg). This will be administered via a 25-G spinal needle at L4-L5 or L3-L4 with the patient in the sitting position under complete aseptic conditions.
Intervention MeSH terms: Anesthetics
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment