Analgesic Efficacy of Bilateral US Guided TTPB vs ESPB in Pediatric Patients Undergoing Corrective Cardiac Surgeries
Condition: Pain, Postoperative
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      Corrective cardiac surgeries include a bundle of major surgeries that take place in pediatric
      patients and require imperative perioperative pain control; hence, the art of healing starts
      from trying to diminish or abolish pain.

      The use of highly potent opioids for paediatric cardiac anaesthesia has gained widespread
      popularity during the last 20 years . In addition to the important advantage of hemodynamic
      stability, the large-dose opioid-based anaesthetic techniques also blunt the stress response;
      however, large doses can cause over sedation, respiratory depression and prolonged mechanical
      ventilation after surgery .

      There are many ways to limit pain in such population with the topper potent opioids in the
      last several years. But new regional pain management modalities started to arise because of
      their known effect to diminish neuroendocrine stress response, provide excellent
      postoperative analgesia, and facilitate early postoperative extubation .

      Of the new evolving methods, the bilateral Transversus Thoracic Muscle Plane Block (TTPB)
      provides analgesia to the anterior chest wall and proved to be efficient in pediatric
      patients undergoing cardiac surgery using a median sternotomy approach .

      The bilateral Erector Spinae Plane Block (ESPB) is also one of the recently known pain
      controlling techniques used in pediatric cardiac surgeries. It became popular because it is
      much safer and easily administered than other alternative regional techniques as thoracic
      paravertebral and thoracic epidural block .
    

Detailed description: 
      I. Study design and randomization

      Our study will be designed to estimate the analgesic effect of single shot bilatral
      transversus thoracic muscle plane block compared to that of erector spinae plane block in
      pediatric patients undergoing corrective cardiac surgeries including atrial septal defect
      (ASD) repair, ventricular septal defect (VSD) repair, atrioventricular (AV) canal repair,
      Glenn procedure, Fontan procedure and subaortic membrane resection. Our primary outcome will
      be the total dose of intra-operative fentanyl boluses.

      Randomization will be achieved by using an online random number generator. Patient codes will
      be placed into sequentially numbered sealed opaque envelopes by a research assistant who is
      not involved in the study. A medical doctor not involved in patient management will be
      responsible for opening the envelope and give the instructions contained within each envelope
      to the anesthesiologist who is expert in doing the ESPB in patients included within the block
      group. This expert anaesthesiologist will not be involved in collecting data but another
      anaesthesist blinded to the type of block will be responsible for patient management and
      collecting the intra-operative and postoperative data.

      II. Study setting and location

      The study will be conducted in the pediatric cardiothoracic operation theatre in Abu El Reesh
      Pediatric Hospital - Cairo University.

      III. Study population

      The study will be conducted on pediatric patients aged 2 months - 4 years, ASA II and III
      undergoing corrective cardiac surgeries (with midline sternotomy incision). The patients will
      be randomly assigned to one of 3 groups Group (A): (Control group): This group will receive
      fentanyl infusion at a dose of (0.5 μg/kg/h) all through the whole operation .

      Group (B): This group will receive fentanyl infusion at a dose of (0.5 μg/kg/h) all through
      the whole operation plus Ultrasound guided bilateral ESPB which will be done by injecting 0.4
      ml/kg (1:1 solution of bupivacaine 0.25% and lidocaine 1%) at each side .

      Group (C): This group will receive fentanyl infusion at a dose of (0.5 μg/kg/h) all through
      the whole operation plus ultrasound guided bilateral TTPB which will be done by injecting 0.4
      ml/kg (1:1 solution of bupivacaine 0.25% and lidocaine 1%) at each side .

      IV. Study Procedures

      -Preoperative:-

      All patients will attend at the pre- anesthesia room with their parents 1 hour before the
      procedure after taking approval of research ethical committee and informed consent.

      Detailed history from the parents will be taken followed by a full and detailed clinical
      examination of the child then all investigations including CBC, coagulation profile, liver
      enzymes, kidney function tests, CXR, echocardiography/cardiac catheterization and blood
      grouping will be checked.

      -Intraoperative:-

      Non-invasive blood pressure, pulse oximetry and ECG will be applied to all patients. All
      patients will be premedicated by intramuscular midazolam 2mg/Kg and atropine 0.2 mg/Kg 20
      minutes before induction of anesthesia.

      Anesthesia will be induced in all patients by sevoflurane5% in 50% O2 followed by placement
      of peripheral I.V cannula and IV administration of fentanyl (0.5 µg/kg). Oral endotracheal
      intubation will be facilitated by IV atracurium 0.5 mg/kg and then capnogram will be
      connected to monitor End-tidal CO2 and muscle relaxation will be maintained by atracurium
      infusion in a dose of 0.5 mg/ kg/ hr.

      All patients will be mechanically ventilated using pressure controlled mode with FiO2 50%,
      PEEP 5 cmH2O, I : E ratio of 1:2, peak inspiratory pressure (PIP) will be set to deliver a
      tidal volume of 6-8 ml/kg and respiratory rate will be 15 to 35 cycle / minute according to
      the age. Our aim is to keep end tidal CO2 between 30-40 mmHg. Isoflurane will be used for
      maintenance of anaesthesia.

      After insertion of a central venous catheter and an arterial cannula, nasopharyngeal
      temperature probe will be placed.

      Patients in Group A will receive fentanyl infusion at a dose of (0.5 μg/kg/h) all through the
      whole operation.

      Patients in Group B will receive fentanyl infusion at a dose of (0.5 μg/kg/h) in addition to
      ultrasound guided bilateral erector spinae plane block by injecting 0.4ml/kg (1:1 solution of
      bupivacaine 0.25% and lidocaine 1%) at each side as follows :

      Under strict aseptic precautions, The T3 spinous process will be located by palpating and
      counting down from the C7 spinous process.

      A high-frequency 12 MHz linear ultrasound transducer will be placed in a longitudinal
      orientation 3 cm lateral to the T3 spinous process corresponding to the T2 transverse
      process.

      Three muscles; trapezius (uppermost), rhomboids major (middle), and erector spinae
      (lowermost) will be identified superior to the hyperechoic transverse process.

      Using in-plane approach a 25 G needle will be inserted in caudal-cephalad direction, until
      the tip is deep to erector spinae muscle.

      Correct needle tip location will be confirmed by injecting 3 mL of normal saline and
      visualizing the linear LA spread (i.e., hydrodissection) in the fascial plane between the
      erector spinae muscle and the transverse process.

      Now, 0.4 ml/kg (1:1 solution of bupivacaine 0.25% and lidocaine 1%) will be injected and
      visualizing the linear LA spread (i.e., hydrodissection) in the fascial plane between the
      erector spinae muscle andthe transverse process.

      Patients in Group C will receive fentanyl infusion at a dose of (0.5 μg/kg/h) plus ultrasound
      guided bilateral transversus thoracic muscle plane block by injecting 0.4ml/kg (1:1 solution
      of bupivacaine 0.25% and lidocaine 1%) at each side as follows :

      Under strict aseptic precautions, the T4-T5 intercostal space is identified under US using
      the US probe in the longitudinal plane 1 cm lateral to the sternal border. A high-frequency
      linear transducer is used.

      Next, a parasternal sagittal view of the intercostal muscle and the transverses thoracis
      muscle between the 4th and 5th rib is visualized above the pleura and a 22G, 5-10 cm needle
      is inserted in-plane (according to patient's body habitus and relevant anatomy) to the
      transducer with bevel up until the tip of the needle is located in the transverses thoracis
      muscles.

      After excluding intravascular and intrapleural placement, local anesthetic is adminstred
      bilaterally by injecting 0.4ml/kg (1:1 solution of bupivacaine 0.25% and lidocaine 1%) at
      each side.

      After 15 min, skin incision will be started and rescue analgesia by a bolus of (Fentanyl
      1mcg/kg) will be given to the patients in each group. If either mean blood pressure (MBP) or
      heart rate (HR) increased more than 20% of the baseline readings (as recorded 5 minutes after
      intubation) provided that there is no other cause of these hemodynamic changes such as
      inadequate anesthesia and surgical complications.

      The block will be considered a failed block if the patient will require more than two boluses
      of fentanyl during the first 30 minutes of the skin incision and this case will be excluded
      from the study.

      -Postoperative:- All patients will be discharged to the pediatric ICU where they will receive
      paracetamol in a dose of 15 mg/ kg I.V. every 6 hours as a standard protocol in our unit.

      Measurement tools:

      Intra-operative:

        -  The total dose of fentanyl will be calculated.

        -  Vital signs including HR and MBP will be recorded at the following intervals; (T1:
           baseline reading 5 min after intubation, T2: after skin incision, T3: after sternotomy,
           T4: after aortic cannulation, T5: after weaning from bypass and T6: after skin closure).

      In the Pediatric ICU:

        -  Time (in minutes) to 1st rescue analgesia post operatively (Fentanyl) which will be
           defined to be the elapsed time between giving the block and a patient FLACC score (Table
           1) equal or more than 4.

        -  Total consumption of Fentanyl during the 1st 12 hours post operatively will be
           calculated.

        -  Haemodynamics including HR and MBP immediately after admission to ICU then at 60 min, 2
           hours, 4hours, 8 hours and 12 hours

        -  The incidence of complications like postoperative vomiting, hematoma formation, itching,
           local anesthetic toxicity.

        -  Pain score assessment immediately after admission to ICU then at 60 min, 2 hours,
           4hours, 8hours and 12 hours postoperatively by FLACC score

             -  How to assess pain using FLACC score:

                  1. Face

                     ● Score 0 point if patient has a relaxed face, eye contact and interest in
                     surroundings

                       -  Score 1 point if patient has a worried look to face, with eyebrows
                          lowered, eyes partially closed, cheeks raised, mouth pursed

                       -  Score 2 points if patient has deep furrows in the forehead, with closed
                          eyes, open mouth and deep lines around nose/lips

                  2. Legs

                     ● Score 0 points if patient has usual tone and motion to limbs (legs and arms)

                       -  Score 1 point if patient has increase tone, rigidity, tense, intermittent
                          flexion/extension of limbs

                       -  Score 2 points if patient has hyper tonicity, legs pulled tight,
                          exaggerated flexion/extension of limbs, tremors.

                  3. Activity

                     ● Score 0 points if patient moves easily and freely, normal
                     activity/restrictions

                     ● Score 1 point if patient shifts positions, hesitant to move, guarding, tense
                     torso, pressure on body part

                     ● Score 2 points if patient is in fixed position, rocking, side-to-side head
                     movement, rubbing body part.

                  4. Cry

                     ● Score 0 points if patient has no cry/moan awake or asleep

                     ● Score 1 point if patient has occasional moans, cries, whimpers, sighs

                     ● Score 2 points if patient has frequent/continuous moans, cries, grunts.

                  5. Consolability ● Score 0 points if patient is calm and does not require
                     consoling ● Score 1 point if patient responds to comfort by touch or talk in
                     ½- 1 minute

                       -  Score 2 points if patient requires constant comforting or unable to
                          console. Pain was assessed by the pediatric observational 10-point scale
                          "Face, Leg, Activity, Cry, Consolability (FLACC) pain score.and if the
                          patient FLACC score equal or more than 4, he will receive morphine i.v
                          0.1mg /kg .
    

Intervention name(s): Erector spinae plane block; Transversus thoracis plane block
Intervention type(s): Procedure; Procedure
Intervention description(s): Under strict aseptic precautions, The T3 spinous process will be located. A high-frequency 12 MHz linear US transducer will be placed in a longitudinal orientation 3 cm lateral to the T3 spinous process corresponding to the T2 transverse process. Three muscles; trapezius (uppermost), rhomboids major (middle), and erector spinae (lowermost) will be identified superior to the hyperechoic transverse process. Using in-plane approach a 25 G needle will be inserted in caudal-cephalad direction, until the tip is deep to erector spinae muscle. Correct needle tip location will be confirmed by injecting 3 mL of normal saline and visualizing the linear LA spread (i.e., hydrodissection) in the fascial plane between the erector spinae muscle and the transverse process. Then, 0.4 ml/kg (1:1 solution of bupivacaine 0.25% and lidocaine 1%) will be injected and visualizing the linear LA spread in the fascial plane between the erector spinae muscle and the transverse process.; Under strict aseptic precautions, the T4-T5 intercostal space is identified under US using the US probe in the longitudinal plane 1 cm lateral to the sternal border. A high-frequency linear transducer is used. Next, a parasternal sagittal view of the intercostal muscle and the transverses thoracis muscle between the 4th and 5th rib is visualized above the pleura and a 22G, 5-10 cm needle is inserted in-plane (according to patient's body habitus and relevant anatomy) to the transducer with bevel up until the tip of the needle is located in the transverses thoracis muscles. After excluding intravascular and intrapleural placement, local anesthetic is adminstred bilaterally by injecting 0.4ml/kg (1:1 solution of bupivacaine 0.25% and lidocaine 1%) at each side.
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: Single (Investigator)
Primary purpose: Health Services Research
Keywords: Transversus thoracic muscle plane block; Erector spinea plane block; Pediatric cardiac surgery; Multimodal anelgesia in pediatric cardiac surgeries; TTPB; ESPB