Determination Of Dispersion In Ultrasound Guided Quadratus Lumborum Block In Cadavers

Overview

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.

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.