Serratus Anterior Plane Block for Modified Radical Mastectomy: Double-point VS Single-point
Condition: Mammary Cancer; Serratus Anterior Plane Block; Postoperative Pain
MeSH terms: Breast Neoplasms; Pain, Postoperative
Study type: Interventional

Summary: 
      Nowadays, the incidence of breast cancer is the first number of malignant tumors, and the
      primary treatment method is surgery. As is known to all, less postoperative complications and
      enhanced recovery are closely related to effective analgesia. However, postoperative patients
      often experience moderate pain, while associated with axillary discomfort. Serratus Anterior
      Plane Block (SAPB) relieves postoperative pain, but traditional single point block method has
      no effect on axillary discomfort. Therefore, it is necessary to try double point blocks to
      explore their impact on postoperative analgesia and axillary comfort. This RCT will recruit
      patients proposed to undergo Modified Radical Mastectomy (MRM) and be randomized to single
      point or double point groups to evaluate their postoperative pain score and axillary comfort
      in order to provide clinical guidance.
    

Detailed description: 
      The conventional SAPB, which often performs single point block from the level of the fifth
      rib, does not completely relieve postoperative pain in patients with axillary lymph node
      dissection, probably due to insufficient range of local anesthetic diffusion.Anatomical study
      indicated that with a double point SAPB at the third and fifth rib levels, respectively, the
      local anesthetic diffusion range can reach the axillary level and may provide better
      analgesic effects. However, the support of clinical data is lacking.Therefore, the hypothesis
      of this study is that double point SAPB will provide better postoperative analgesia compared
      with conventional single point SAPB in patients undergoing modified radical mastectomy.This
      study will include 60 patients proposed to undergo modified radical mastectomy, allocated to
      the Double-point or Single-point group in a 1:1 ratio, randomly.The Double-point group will
      perform a double point SAPB, which is a combined block at the third and fifth rib levels,
      respectively.The Single-point group will undergo a single point SAPB, traditionally performed
      at the level of the fifth rib.Observation outcomes included changes in blood pressure and
      heart rate during dissection of skin and dissection of axillary lymph nodes, postoperative
      pain scores, axillary comfort, recovery quality, and related complications and postoperative
      hospital stay.Therefore, the objective is to investigate whether this simple technical
      modification can better reduce postoperative pain and promote rehabilitation in patients with
      modified radical mastectomy.
    

Intervention name(s): Double-point SAPB; Single-point SAPB
Intervention type(s): Procedure; Procedure
Intervention description(s): A high-frequency linear probe (6-13 MHz) of the ultrasound machine was used to identify the fifth rib in the midaxillary line. The anatomic landmarks of the block were identified: latissimus dorsi, serratus anterior, and the intercostal muscles in the fourth and fifth intercostal levels. After sterilization and draping, an 20-gauge needle was introduced craniocaudally using an in-plane technique. The needle tip was advanced, targeting the plane between the serratus anterior muscle and the fifth rib. Needle position was confirmed by injection of 1-to-2 mL of saline after negative aspiration. And use the same method targeting the plane between the serratus anterior muscle and the third rib.Under real-time visualization, total 30 mL of 0.375% ropivacaine and 0.5 μ g/kg dexmedetomidine mixture will be injected into the two points with 15 ml separately.; A high-frequency linear probe (6-13 MHz) of the ultrasound machine was used to identify the fifth rib in the midaxillary line. The anatomic landmarks of the block were identified: latissimus dorsi, serratus anterior, and the intercostal muscles in the fourth and fifth intercostal levels. After sterilization and draping, an 20-gauge needle was introduced craniocaudally using an in-plane technique. The needle tip was advanced, targeting the plane between the serratus anterior muscle and the fifth rib. Needle position was confirmed by injection of 1-to-2 mL of saline after negative aspiration.Under real-time visualization, total 30 mL of 0.375% ropivacaine and 0.5μ g/kg dexmedetomidine mixture will be injected.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Mammary Cancer; Serratus Anterior Plane Block; Postoperative Pain; Axillary Discomfort