Analgesic Efficacy of Transversus Thoracic Muscle Plane Block on Post-sternotomy Pain
Condition: Postoperative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      Patients were randomly allocated to either Tansversus group (T group) and general anesthesia
      (N group).Patient demographic data, preoperative medical status, left ventricular function,
      and operative data (total ischemic time, number of grafts) were recorded. The primary outcome
      of the study was Percentage of patients needed additional doses of morphine . The secondary
      outcomes included postoperative visual analogue pain scores performed after patient
      extubation for pain assessment at rest (0 = no pain, 10 = maximum unbearable pain) at time of
      extubation, 8h, 12 h,18 h and 24 hours postoperatively were recorded, when pain score >4,
      patients were given morphine 0.05 mg/kg administered by a physician who was blinded to the
      nature of the study, time needed for first rescue analgesic, postoperative blood pressure and
      heart rate were recorded immediately on admission then 2 hours, 4 hours, 6 hours, 12 and 24
      hours postoperatively, in addition to extubation time, length of ICU stay, the incidence of
      complications related to the technique such as hemothorax or pneumothorax, arrhythmias, and
      local anesthetic toxicity were recorded. The end-point was difficult weaning from
      cardiopulmonary bypass, major postoperative bleeding which required re-exploration or allergy
      to any agents needed for anesthesia. All complications were managed according to surgical and
      medical guidelines.
    

Detailed description: 
      Patients were randomly allocated to either Tansversus group (T group) and general anesthesia
      (N group). The patients were randomized using a computer-generated random number in various
      block sizes in 1:1 ratio. Randomisation was done using the SAS statistical package version
      9.3 (SAS institute, Cary, NC, USA) by a statistician who was not involved in the study.

      In the Tansversus group (n=30), prior to surgical incision, a 12 L-RS linear probe of the
      Sonosite M Turbo ultrasound system (National electrical manufacturers, USA). Probe was put
      beneath the clavicle next to the sternal edge and the second rib was visualized. Sliding the
      probe on the ribs downward till reaching the fifth rib. The probe was rotated 90 degrees and
      placed in the fouth intercostal space between the fourth and fifth ribs at the edge of the
      sternum. A 20-gauge Tuohy needle was introduced from lateral-to-medial in the plane between
      the internal intercostal muscles IIM and the transversus thoracic muscle TTM. Injection of 1
      mL of normal saline was done to identify this plane followed by injection of 15 ml
      bupivacaine 0.25% on each side and observation of the local anesthetic spread, and pushing on
      the pleura confirmed the correct injection of the local anesthetic. This technique was done
      on the other side. It is important to identify the internal mammary artery IMA which was
      visualized as a hypoechoic pulsatile structure to avoid inadvertent puncture of the artery
      and subsequent bleeding and proper visualization of the IMA can facilitate the block. In N
      group (n=30), the same bilateral technique was done on both sides and 15 ml saline was
      injected during each side of TTPB technique. All the blocks were done by a single experienced
      anesthetist. Drug packs were prepared before commencement of the study by a pharmacist who
      was unaware of the nature of the study Hemodynamic changes, such as high blood pressure or
      significant tachycardia, additional 0.5- to-1 micrograms/kg IV doses of fentanyl were
      administered.

      Median sternotomy was performed in all cardiac surgical procedures. At the end of the cardiac
      surgical procedure, all patients were transferred to the ICU after surgery to maintain the
      hemodynamics, warming them up with control of bleeding and correction of hemoglobin level,
      serum electrolytes and acid-base balance. A standard postoperative analgesia was accomplished
      by acetaminophen 1 gm/6 hours.The protocol for postoperative care was implemented for all
      patients by well-trained, qualified bedside nurses supervised 1:1 by well-trained ICU
      consultants. All patients were extubated when deemed clinically appropriate according to the
      local ICU protocol, by ICU staff, when the patient was able to maintain spontaneous breathing
      after extubation. The patients were encouraged to sit on a chair and mobilize with the
      assistance of health care providers in the ICU then the physiotherapist became responsible
      for improving mobility and rehabilitation of the patients till discharge from the hospital.

      Patient demographic data, preoperative medical status, left ventricular function, and
      operative data (total ischemic time, number of grafts) were recorded. The primary outcome of
      the study was Percentage of patients needed additional doses of morphine The secondary
      outcomes included total dose of morphine requirements, postoperative visual analogue pain
      scores performed after patient extubation for pain assessment at rest (0 = no pain, 10 =
      maximum unbearable pain) at time of extubation, 8h, 12 h,18 h and 24 hours postoperatively
      were recorded, when pain score >4, patients were given morphine 0.05 mg/kg administered by a
      physician who was blinded to the nature of the study, time needed for first rescue analgesic,
      postoperative blood pressure and heart rate were recorded immediately on admission then 2
      hours, 4 hours, 6 hours, 12 and 24 hours postoperatively, in addition to extubation time,
      length of ICU stay, the incidence of complications related to the technique such as
      hemothorax or pneumothorax, arrhythmias, and local anesthetic toxicity were recorded. The
      end-point was difficult weaning from cardiopulmonary bypass, major postoperative bleeding
      which required re-exploration or allergy to any agents needed for anesthesia. All
      complications were managed according to surgical and medical guidelines.
    

Intervention name(s): transversus thoracic muscle plane block; general anaesthesia
Intervention type(s): Other; Other
Intervention description(s): transversus thoracic muscle plane block by injection of 15 ml of bupivacaine 0.25% on each side combined with general anaesthesia; transversus thoracic muscle plane block by injection of 15 ml of saline on each side combined with general anaesthesia
Intervention MeSH terms: Anesthetics
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: transversus thoracic muscle block; adults; cardiac surgery