Determination Of Dispersion In Ultrasound Guided Quadratus Lumborum Block In Cadavers

Study Overview
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Brief Summary
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Lumbar Quadrant Blockade is a recent analgesic technique consisting of the injection of local anesthetic around the lumbar square muscle. It was initially described as a technique for abdominal wall analgesia, but later studies have increased the range of indications for laparoscopic and lower limb surgeries. There are several techniques described but with differences in the literature at the point of injection and volume of anesthetic. The exact mechanism of visceral analgesia has not yet been determined. The objective of this study is to determine the dispersion of local anesthetic as a variable dependent on the volume of local anesthetic and injection site and elucidate the mechanisms of analgesia.

Detailed Description
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After the free and informed consent signed by the family authorizing the procedure, demographic and clinical data will be collected from the medical records of the deceased. The corpse will be weighed, measured and placed on the autopsy table. Blockade randomization (QLB 2 or QLB 3) and volume of local anesthetic (10ml, 20ml, 30ml) will be performed for each side. Injection in the anterior or posterior plane to the Lumbar Quadrant muscle will be performed by anesthesiologists experienced in the technique with ultrasound aid. A colouring solution will be used. After confirming the correct needle position, the previously randomized volumes will be injected. After the blockage, the corpse will be placed in the supine position and will be submitted to autopsy by standard procedure. After removal of the thoracic and abdominal viscera, the investigators will verify the dispersion of the local anesthetic. Photographic records will be made and the number of levels by which the solution dispersed will be annotated, calculating the number of cranial and caudal levels. The corpse will then have its autopsy procedure completed, with the placement of the viscera and incision closure according to the service standard.

Official Title
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Determination Of The Relationship Between Local Anesthetic Volume And Its Dispersion In Ultrasound Guided Quadratus Lumborum Block In Cadavers

Conditions
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Nerve Block

Intervention / Treatment
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* Procedure: Quadratus Lumborum Block type 2
* Procedure: Quadratus Lumborum Block type 3


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Fresh corpses - not subjected to a formaldehyde process or frozen for more than 24 hours Age ≥ 18 years. Free, informed and informed consent signed by relatives or guardians of the body. Height> 150 cm and <190 cm Exclusion Criteria: Previous spinal surgery. Significant spinal deformity Body mass index (BMI) ≥ 35 kg / m2 Absence of relatives or guardians who can sign the written consent

Ages Eligible for Study
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Minimum Age: 18 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: the cadavers will be randomized to receive the intervention (Quadratus Lumborum Block) by different techniques (QLB 2/ QLB3) and different volumes (10, 20, 30 ml)
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: QLB 2 10ml<br>The cadaver will receive an ultrasound- guided Quadratus Lumborum Block type 2 with 10 ml coloring solution | Procedure: Quadratus Lumborum Block type 2<br>* Ultrasound guided injection of coloring solution using a 18g Tuohy echogenic needle, posterior to the Quadratus Lumborum muscle<br>|
| Experimental: QLB 2 20ml<br>The cadaver will receive an ultrasound- guided Quadratus Lumborum Block type 2 with 20 ml coloring solution | Procedure: Quadratus Lumborum Block type 2<br>* Ultrasound guided injection of coloring solution using a 18g Tuohy echogenic needle, posterior to the Quadratus Lumborum muscle<br>|
| Experimental: QLB 2 30ml<br>The cadaver will receive an ultrasound- guided Quadratus Lumborum Block type 2 with 30 ml coloring solution | Procedure: Quadratus Lumborum Block type 2<br>* Ultrasound guided injection of coloring solution using a 18g Tuohy echogenic needle, posterior to the Quadratus Lumborum muscle<br>|
| Experimental: QLB 3 10ml<br>The cadaver will receive an ultrasound- guided Quadratus Lumborum Block type 3 with 10 ml coloring solution | Procedure: Quadratus Lumborum Block type 3<br>* Ultrasound guided injection of coloring solution using a 18g Tuohy echogenic needle, anterior to the Quadratus Lumborum muscle<br>|
| Experimental: QLB 3 20ml<br>The cadaver will receive an ultrasound- guided Quadratus Lumborum Block type 3 with 20 ml coloring solution | Procedure: Quadratus Lumborum Block type 3<br>* Ultrasound guided injection of coloring solution using a 18g Tuohy echogenic needle, anterior to the Quadratus Lumborum muscle<br>|
| Experimental: QLB 3 30ml<br>The cadaver will receive an ultrasound- guided Quadratus Lumborum Block type 3 with 30 ml coloring solution | Procedure: Quadratus Lumborum Block type 3<br>* Ultrasound guided injection of coloring solution using a 18g Tuohy echogenic needle, anterior to the Quadratus Lumborum muscle<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Spread of coloring solution according to the volume injected | Observation of coloring solution around the spinal nerves as they exit the vertebral foramen. Comparison of number of spinal nerves colored according to the volume injected. | 3 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Spread of coloring solution to the paravertebral space | Observation of coloring solution on the paravertebral space. Comparison of spread to the paravertebral space according to the volume injected. | 3 hours | 
| Comparison of spread of the coloring solution between QLB 2 and QLB3 | Observation of coloring solution around the spinal nerves as they exit the vertebral foramen and spread to the paravertebral space. Comparison of number of spinal nerves colored according to the technique used. | 3 hours |