Single Versus Multiple Injection Ultrasound Guided Paravertebral Blocks
Condition: Breast Neoplasms; Anesthesia
MeSH terms: Breast Neoplasms
Study type: Interventional

Summary: 
      Paravertebral block (PVB) has been shown to provide excellent analgesia for major breast
      surgeries resulting in reduced narcotic consumption, reduced nausea, improved quality of
      recovery, reduced chronic pain and possibly reduced metastasis with breast cancer.
      Traditionally, PVB is done by multiple injections below T1-T5 transverse processes. With
      multiple injections, the risk is increased for a pleural, an intraneural, and/or an
      intravascular injection. Recently, ultrasonography is being used to facilitate PVB. The use
      of ultrasound imaging enables real-time needle visualization during the procedure. This may
      improve efficacy and reduce the chances of complication like pneumothorax. Currently, there
      are no data comparing ultrasound-guided single injection technique with multiple injections
      technique with regards to extent of spread for PVB. Our objective is to investigate the
      extent of dermatomal spread of PVB when equal volumes of local anesthetic are injected at one
      versus five paravertebral sites for patients undergoing major breast surgery. In addition,
      the investigators wish to compare the performance time and duration of analgesia.

      Methodology: After local REB approval, 72 patients undergoing a unilateral mastectomy with or
      without axillary node dissection will be randomized to receive either single or multiple
      injections PVB. The PVB will be performed in prone position under real-time ultrasound
      guidance using a para-sagittal approach.The patients in single injection group will receive
      single injection PVB at T3-T4 level with 25 ml of 0.5% ropivacaine and four subcutaneous sham
      injections. Patients in the multiple injection group will receive five injections of PVB from
      T1 to T5 level. 5 ml of 0.5% ropivacaine will be injected at each level. Pleural drift will
      be used as a sign of correct needle tip location and local anaesthetic spread. The pinprick
      method will be used to assess the extent of dermatomal blockade, 20 minutes following the
      completion of procedure. All patients will receive a standardized general anesthesia for the
      surgery. Any adverse events including pneumothorax, epidural spread, LA toxicity/seizure,
      total spinal, will be recorded.
    


Intervention name(s): Single injection paravertebral block; Multiple injection paravertebral blocks
Intervention type(s): Procedure; Procedure
Intervention description(s): The patients in single injection group will receive single injection paravertebral block at T3-T4 level with 25 ml of 0.5% "ropivacaine" and four subcutaneous sham injections; Patients in the multiple injection group will receive five injections of paravertebral blocks from T1 to T5 level. 5 ml of 0.5% "ropivacaine" was injected at each level.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment