The Difference Between the Extrafascial Injection and the Subfascial Injection of Quadratus Lumborum Block
Condition: Postoperative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      Quadratus lumborum block can be used for the hip surgery and abdominal surgery postoperative
      analgesia. But the lower thoracic to the hip dermatome can't be blocked at the same time. The
      anesthetists used the same method, but had produced the different dermatome were blocked. The
      investigators hypothesized that this was due to local anesthetics was injected to different
      locations of the anterior thoracolumbar fascia. If the investigators inject local anesthetics
      to the anterior layer of thoracolumbar extrafascial, this produced the dermatomal coverage
      from lower abdominal to hip. A different situation was when the investigators injected local
      anesthetics to anterior thoracolumbar subfascia, the lower thoracic dermatome were blocked.
    

Detailed description: 
      Quadratus lumborum block can be used for the hip surgery and abdominal surgery postoperative
      analgesia. But the lower thoracic to the hip dermatomes can't be blocked at the same time.
      The anesthetists used the same method, but had produced the different dermatomes were
      blocked. The investigators hypothesized that this was due to local anesthetics was injected
      to different locations of the anterior thoracolumbar fascia. If the investigators inject
      local anesthetics to the anterior thoracolumbar extrafascial (between the anterior layer of
      thoracolumbar fascia and psoas major muscle), this produced the dermatomal coverage from
      lower abdominal to hip. In this case, the investigators speculated the local anesthetic
      spread to the lumbar paravertebral space via the fascia and the fascicle of psoas major. A
      different situation was when the investigators injected local anesthetics to anterior
      thoracolumbar subfascial (between the anterior layer of thoracolumbar fascia and quadratus
      lumborum), the lower thoracic dermatomes were blocked. The investigators speculate that the
      local anesthetic injected subfascial could spread cephalad to lower thoracic paravertebral
      space posterior to the endothoracic fascia via lateral arcuate ligament.

      The investigators confirm the hypothesis in the pilot trial. therefore, the investigators
      need to trial with large sample. The investigators plan to improve the clinical guidance of
      quadratus lumborum block technology, so that more patients benefit.
    

Intervention name(s): Ropivacaine
Intervention type(s): Drug
Intervention description(s): Subfascial injection OR extrafascial injection
Other intervention name(s): Naropin
Intervention MeSH terms: Ropivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: The investigators random divided subjects into two groups, the "subfascial injection group"and the "extrafascial injection group". Two groups were injected 0.33% ropivacaine 30 ml to the target location.
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Treatment
Keywords: quadratus lumborum block; anterior thoracolumbar fascia; subfascial injection; extrafascial injection