Ultrasound Guided Local Anesthetic Field Block (A Five Step Procedure) for Open Inguinal Hernia Repair

Study Overview
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Brief Summary
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The aim of this study is to evaluate success, efficacy, feasibility and safety of a simple five step ultrasound guided local anesthetic infiltration technique for unilateral open inguinal hernia repair and to determine the non-inferiority of the block to spinal anesthesia by comparing intraoperative and postoperative complications, pain control and patient and surgeon satisfaction of the block with spinal anesthesia.

Detailed Description
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Open Inguinal hernia repair is one of the commonest procedures performed worldwide. Still, there is no consensus regarding the optimum anesthesia technique for this surgery. General, spinal, epidural and local anesthesia techniques have all been used, each having its own advantages and disadvantages. General anesthesia carries risks of possible airway complications, postoperative deterioration of cognitive function, sore throat, nausea, vomiting and prolonged period of immobilization with associated risk of deep vein thrombosis and longer hospital stay. Spinal anesthesia, although effective, is not without risk in patients with decompensated heart disease, recent head injury, convulsions and coagulopathies. Also spinal and epidural anesthesia have been associated with hemodynamic instability, vomiting, urinary retention, post-dural puncture headache, and backache. Use of pre-incision infiltration of local anesthetics for field blocks has been found to be an effective adjunct as well as an alternative to spinal and general anesthesia in many studies. Combined with sedation or on its own, it offers less cardiovascular instability, early ambulation and effective post-operative pain control. Also, it has been found to reduce hospital costs by 50% and gives better patient satisfaction. Harvey Cushing and William Halsted first described the inguinal field block in 1900. since then, its efficacy and advantages have been compared by many surgeons and anesthesiologists in a number of studies. Refinements and modifications in the technique still continue. In 1963, Joseph L Ponka described in great detail a seven step procedure of performing it in 837 patients successfully. In 1994, Parvis and colleagues did a step by step technique for local anesthetic infiltration field block for open inguinal hernia repair. Ultrasonography is a safe and effective form of imaging. Over the past two decades, ultrasound equipment has become more compact, of higher quality and less expensive. Ultrasounds have been used to guide needle insertion and a number of approaches to nerves and plexuses have been reported. A clear advantage of the technique is that ultrasound produces living pictures or real-time images. The identification of neuronal and adjacent anatomical structures (blood vessels, peritoneum, bone, organs) along with the needle is another advantage. Moreover, anatomical variability may be responsible for block failures, and ultrasound technology enabling direct visualization may overcome this problem. Sonographic visualization allows for the performance of extra-epineurial needle tip positioning and administration of local anesthetic avoiding intra-epineurial injection. A modification to the technique performed by Parvis and colleagues will be tested in this study. Our modification will be performing the technique under ultrasound guidance and completely before skin incision, which, to the best of our knowledge, was not attempted in the literature before. Local anesthesia administered before skin incision produces longer postoperative analgesia because local infiltration theoretically inhibits the build-up of local nociceptive molecules and, therefore, there is better pain control in the postoperative period.This study aims at evaluating success, efficacy, feasibility and safety of a simple five step ultrasound guided local anesthetic infiltration technique for unilateral open inguinal hernia repair and also to compare intraoperative and postoperative complications and pain control of the block with spinal anesthesia.

Official Title
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Efficacy of Ultrasound Guided Local Anesthetic Field Block (A Five Step Procedure) as a Sole Anesthetic for Open Inguinal Hernia Repair Versus Spinal Anesthesia: A Randomized Controlled Study.

Conditions
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Inguinal Hernia

Intervention / Treatment
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* Procedure: US guided five step field block
* Procedure: Spinal anesthesia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA score I, II or Ш. Patients with unilateral inguinal hernia for elective open mesh repair hernioplasty operation. Exclusion Criteria: Bilateral, recurrent or complicated inguinal hernia. Emergency operations or operation that lasts more than two hours. Patients with drug or alcohol abuse history. Chronic pain, with daily use of analgesics. Contraindication to local anesthesia. Contraindication of spinal anesthesia.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: A Randomized Controlled study.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group A<br>US guided five step field block will be performed | Procedure: US guided five step field block<br>* Ultrasound will guide needle insertion in the following layers (except intradermic injection): Subdermic infiltration. Approximately 8 milliliters Intradermic injection (making of the skin wheal). of approximately 6 milliliters. Deep subcutaneous injection. 8 milliliters of the mixture will be injected deep into the subcutaneous adipose Subfascial infiltration. Approximately eight milliliters of the anesthetic mixture will be injected immediately underneath the aponeurosis of the external oblique. Pubic tubercle and hernia sac injection. Occasionally, infiltration of ten milliliters of the mixture at the level of the pubic tubercle, around the neck and inside the indirect hernia sac<br>|
| Active Comparator: Group B<br>Spinal anesthesia will be administered in sitting position | Procedure: Spinal anesthesia<br>* Spinal anesthesia will be administered in sitting position, with 25 gauge Quincke spinal needle in L3-L4 intervertebral space, under all aseptic precautions and local infiltration, with 3.0 ml of 0.5% bupivacaine (heavy) after ensuring free, clear and adequate flow of cerebrospinal fluid. After giving spinal anesthesia, patient will be made to lie supine.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| NRS 4 hours postoperative | Numerical Rating pain score 4 hours postoperative | 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| NRS 30 minutes postoperative | Numerical Rating pain score 30 minutes postoperative. | 30 minutes | 
| NRS 12 hours postoperative | Numerical Rating pain score 12 hours postoperative. | 12 hours | 
| Time of first rescue analgesic dose | The time of request for the first rescue dose of analgesic medication | 12 hours | 
| Total analgesic dose in the first 12 hours postoperative | The total doses of analgesics needed (whether opioids or non-opioids) to maintain an NRS score < 3 over the first 12 hours post-operative | 12 hours | 
| Incidence of Side effects | Complications including nausea, vomiting, wound hematoma, hypotension, persistent headache and urinary retention | 12 hours | 
| Time for ambulation | The time needed to start pain free unassisted ambulation and the duration of hospital stay. | 12 hours | 
| Intra operative patient satisfaction | Intra operative patient satisfaction (rated as 1 to be very satisfied, 2 moderately satisfied and 3 poorly satisfied.) | 12 hours | 
| Intra operative surgeon satisfaction | Intra operative surgeon satisfaction with the type of anesthesia (satisfied or not) | 12 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hernia, Local anesthesia, ultrasound