Ultrasound-guided Inguinal Field Block (Genitofemoral, Iliohypogastric and Ilioinguinal Nerve Block) for Inguinal Hernia Surgery

Study Overview
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Brief Summary
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The purpose of this study is to investigate the analgesic efficacy of an ultrasound-guided inguinal field block (block of the genitofemoral, iliohypogastric and ilioinguinal nerve).

Detailed Description
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Inguinal hernia repair accounts for 10-15% of all operations in general surgery. Moderate to severe pain can occur at the first day after inguinal hernia repair in 25% of patients at rest and in 60% during activity. On day 6 after the operation the incidence can be as high as 11% at rest and 33% during activity. Ultrasound imaging for regional anesthesia techniques have improved the success and safety rate of nerve blocks. We hypothesized that a procedure consisting of an ultrasound-guided inguinal field block (genitofemoral, iliohypogastric and ilioinguinal nerve block and incision line infiltration) could effectively control postoperative pain compared to selective unilateral subarachnoid anesthesia.

Official Title
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Analgesic Efficacy of Ultrasound-guided Inguinal Field Block (Genitofemoral, Iliohypogastric and Ilioinguinal Nerve Block) for Inguinal Hernia Surgery.

Conditions
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Inguinal Hernia

Intervention / Treatment
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* Other: Triple inguinal nerve block.
* Other: Unilateral subarachnoid anesthesia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI (Body mass index) < 30 Non severe liver, renal or cardiac disease No allergy or contraindications to any of the study drugs American Hernia Society Score type I-II-IV-V hernia No pain or chronic analgesic administration in the preoperative period No previous surgery of the inguinal region Normal coagulation parameters and platelet count (> 100.000). Dicumarol and aspirin suspension for > 7 days Correctly administrated premedication No systemic infections No contraindications to subarachnoid anesthesia Exclusion Criteria: BMI (Body mass index) > 30 Severe liver, renal or cardiac disease Allergy or contraindications to any of the study drugs American Hernia Society Score type III-VI-VII-0 hernia Pain or chronic analgesic administration in the preoperative period Previous surgery of the inguinal region Anormal coagulation parameters and platelet count (< 100.000). No dicumarol and aspirin suspension for > 7 days Incorrectly administrated premedication Systemic infections Contraindications to subarachnoid anesthesia

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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Male

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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Triple inguinal nerve block<br>Ropivacaine 5 mg/ml | Other: Triple inguinal nerve block.<br>* Ultrasound-guided genitofemoral, iliohypogastric and ilioinguinal nerve block with ropivacaine 5 mg/ml, 150 mg.<br>* Other names: Regional anesthesia for the groin.;|
| Active Comparator: Unilateral subarachnoid anesthesia<br>Bupivacaine 10 mg/ml | Other: Unilateral subarachnoid anesthesia<br>* Subarachnoid anesthesia with hyperbaric bupivacaine 10 mg/ml, 12 mg, homolateral to inguinal hernia.<br>* Other names: Regional anesthesia for the groin.;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Intensity. | Postoperative pain will be assessed by numeric ranking scale (numeric ranking scale NRS 0 to 10 points) at rest (static numeric ranking scale NRS) and during activity (dynamic numeric ranking scale NRS). | Up to 24 hours. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Supplemental local anesthesia infiltration | If needed, surgeons can infiltrate tissues with 15 ml of ropivacaine 5 mg/ml. | During surgery, up to 2 hours. | 
| Conversion to general anesthesia. | Patients will receive remifentanil adjusted to maintain spontaneous breathing and conscious sedation with a Ramsay score = 2 during surgery if modest pain (numeric ranking scale NRS > 4 and agitation) is sustained. If remifentanil is not sufficient for restoring patient comfort, the block will be considered failed and the patient will be given general anesthesia with propofol and a Proseal Laryngeal Mask. | During surgery, up to 2 hours | 
| mPADSS (Post-Anesthesia Discharge Scoring System) | Assessed at every evaluation time postoperatively. The modified Post-Anesthesia Discharge Scoring System (mPADSS) includes stable heart and respiratory rates, absence of excessive nausea and pain, no bleeding from the surgical site, and ability to walk without support. | Up to 24 hours | 
| Analgesic requirement | Assessed at every evaluation time postoperatively. | Up to 7 days | 
| Activity | Assessed through the activities assessment questionnaire 7 days after surgery. | Up to 7 days | 
| Adverse events. | Assessed at every evaluation time and including surgical and anesthesiological related events. | Up to 7 days | 
| Time from the end of anesthesia to first micturition. | Assessed at every evaluation time postoperatively. | Up to 24 hours. | 
| Time from the end of surgery to the first unassisted walking. | Assessed at every evaluation time postoperatively. | Up to 24 hours. | 
| Total intrahospital stay. | Assessed at every evaluation time postoperatively. | Up to 24 hours. |