Paravertebral Block Versus Erector Spinae Plane Block for Analgesia in Modified Radical Mastectomy
Condition: Postoperative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      The study is planned to be a single-center randomized, prospective double-blind study and
      includes patients who planned to be done unilateral MRM (modified radical mastectomy)
      operation in Istanbul University Istanbul Faculty of Medicine. The objective of this study is
      to compare postoperative analgesic efficacies of TPVB (thoracic paravertebral block) and ESPB
      (erector spinae plane block) performed under ultrasound (USG) guidance after MRM. Primary
      outcome of this study is postoperative 24-hour morphine consumption whereas secondary
      outcomes were planned as the comparison of changes in hemodynamic parameters and numeric
      rating pain score (NRS).
    

Detailed description: 
      A total of 86 patients were randomized into TPVB (Group P) and ESPB (Group E) by using closed
      envelopes.

      All patients in the operating room has same anesthetic management under standard monitoring
      modalities. Prior to regional technique, mild sedation was achieved with midazolam (1-2 mg)
      and fentanyl (50 mcg). Both blocks were performed under ultrasonography guidance from the
      level of T4 vertebra with a linear probe (5MHz; GE Healthcare, Wauwatosa, Wis, USA) using
      longitudinally out-of-plane technique by an anesthesiologist. A 22-gauge, 50 mm insulated
      stimulating needle was used.By using reference points of C7 and T7, spinous processes of
      thoracic vertebras were marked. 10% povidone iodine was used for skin antisepsis. USG probe
      was longitudinally placed at the level of T4. Staff anesthesiologist had to visualize of
      adjacent muscles, transverse process (TP) and pleura.

      For ESPB; confirmation of the needle position was achieved with spread of 2 ml saline between
      the deep fascia of the erector spinae muscle and the TP. After negative aspiration 20 ml
      0.375% bupivacaine was injected with appropriate distribution of LA.

      For TPVB; the needle was advanced passing over superior costotransverse ligament and target
      space was confirmed by the downward displacement of pleura after the administration of 2 ml
      0.9% NaCl. After negative aspiration, 20 ml 0.375 % bupivacaine was injected with appropriate
      distribution of local anesthetics.

      Vascular puncture, haematoma, neuraxial injury and pneumothorax were defined as block
      complications and should be noted.

      30 minutes after the block achieved, pinprick test was performed on both mid-axillary and
      midclavicular lines from T1 to T12 (0 there is sensation, 1 decreased sensation, 2 there is
      no sensation).

      Anesthesia induction was unique for all patients with 0.03 mg kg-1 midazolam, 0.5 mcg kg-1
      fentanyl, 2 mg kg-1 propofol and 0.6 mg kg-1 rocuronium. Maintenance was achieved with
      sevoflurane of 1 minimum alveolar concentration in a mixture of 40% O2 and 60% N2O. As a
      component of multimodal analgesia, paracetamol (1 gr) was applied to all patients before skin
      incision.

      Hemodynamic data were recorded throughout surgery. An increase more than 20% from baseline in
      mean arterial pressure (MAP) was defined as inadequate analgesia and was treated with bolus
      fentanyl (50 mcg). Hypotension was described with a decrease more than 20% in MAP and treated
      with ephedrine bolus. Bradycardia was determined with a heart rate (HR) less than 50 beats
      min-1 and treated with atropine. At the end of surgery, the patients were extubated in
      operating room.

      Postoperative analgesia was achieved with IV morphine via Patient Controlled Analgesia (PCA)
      for 24 hours (0.01 mg kg-1 h-1 basal infusion, 1 mg bolus, 20 minutes lock-out time).

      Postoperative follow-up included hemodynamic variables as well as pain scores and morphine
      consumption. Adequate analgesia at rest (static) and at moving of the arm interpreted as
      45-90 degree abduction (dynamic) was investigated with Numeric Rating Scale (NRS) at 30th
      minute and 1st, 4th, 6th, 12th, 24th hours postoperatively. When NRS was 4 and higher,
      tramadol should be administered as rescue analgesic. In case of insufficient pain control at
      30th minute, dermatomal analgesia should be assessed for both mid-axillary and midclavicular
      lines from T1 to T8 by pinprick test (0 there is sensation, 1 decreased sensation, 2 there is
      no sensation). Morphine consumption was evaluated at same study times.

      Complications were determined as sedation assessed by Ramsey scale, postoperative nausea-
      vomiting (PONV) assessed with the four-point categorical scale (0=no PONV, 1=mild nausea,
      2=severe nausea or vomiting once, and 3=vomiting more than once). Severe vomiting should be
      treated in a multimodal way and excluded from the study (category 2,3).

      Staff anesthesiologist responsible for operative course did not contribute in analgesia
      assessment, nor in other postoperative follow-up. Other investigators who were blinded to
      operative management, collected postoperative data.
    

Intervention name(s): TPVB; ESPB; Bupivacain
Intervention type(s): Procedure; Procedure; Drug
Intervention description(s): 20 ml 0.375 % bupivacaine was injected between superior costotransverse ligament and pleura.; 20 ml 0.375 % bupivacaine was injected between deep fascia of the erector spinae muscle and transverse process.; 20 ml 0.375 % bupivacaine was injected
Intervention MeSH terms: Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Acute postoperative pain; Nerve block; Thoracic wall