This prospective randomized double blinded controlled study was carried out on 50
pediatric patients who scheduled to undergo elective laparoscopic abdominal surgeries
admitted to Cairo University Specialized Children Hospital in the duration from
…...to…...after the approval of ethical committee. Group M-TAPA (group A) (n=25):
Patients received M-TAPA block after induction of GA.

• Group ESPB (group B) (n=25): Patients received ESPB after induction of GA. Patients and
outcome assessors were blinded to the group of the patients. A pharmacist who is not
involved in the study prepared the interventional medications. Methods

Preoperative assessment:

Medical and surgical history of the patients were taken, clinical examination of the
patients was performed and routine laboratory investigations such as CBC, coagulation
studies (INR), renal function (serum creatinine) and liver function (SGPT, SGOT) were
done. Each patient was instructed about postoperative pain assessment with the Face,
Legs, Activity, Cry and Consolability (FLACC) scale. FLACC (0 represents "no pain" while
10 represents "the maximum pain").

Intraoperative:

On entering the operating room: all patients were connected to standard ASA monitoring
which included electrocardiography (ECG), non-invasive arterial blood pressure (NIBP)
including systolic, diastolic & mean arterial blood pressure (MAP), Oxygen saturation
using pulse oximetry. An intravenous wide pore cannula was inserted in the upper limb
then preoperative preload in the form of 10 mL/kg of Ringer's lactate solution for 15
minutes were given. General anesthesia (GA) was induced with propofol 1.5-2.5 mg/kg, and
fentanyl 1µg/kg. After IV Tracrium 0.15 mg/kg, the endotracheal tube was inserted.

Maintaining GA was done with sevoflurane (2%) and 50% oxygen. Incremental doses of IV
Tracrium 0.03mg/Kg will be given. The cases were then mechanically ventilated to sustain
end-tidal CO2 levels of 30-35 mmHg. Additional fentanyl bolus dosages of 0.5 µg/kg IV
were administered if heart rate or mean arterial blood pressure elevated more than 20% of
the baseline (after exclusion of other causes than pain). ESPB and M-TAPA were performed
after the induction of general anesthesia. Both blocks were performed using ultrasound
guidance (FUJiFilM sonosite) with a linear probe (6-13 MHz) under complete aseptic
conditions. The blocks were administered before the surgical incision, with a waiting
period of at least 30 minutes. ESPB and M-TAPA were performed by an experienced
anesthesiologist. Aspiration before injection and test dose injection were performed.
Both blocks were performed bilaterally to ensure adequate analgesia for both sides of the
abdomen. This was essential to achieve full pain relief for laparoscopic abdominal
surgeries, which involve multiple abdominal regions.

In (Group A):

The patient was positioned in a supine posture. A deep angle was given to the
costochondral angle at the edge of the 10th costa with the probe in the sagittal
direction to view the lower surface of the costal cartilage in the midline. A 22-G, 50-mm
block needle was inserted in the cranial direction using the in-plane technique and the
needle tip was moved to the posterior aspect of the 10th costal cartilage. It was noted
that the needle tip never crossed the cranial edge of the 10th costal cartilage and 0.4
ml/kg bupivacaine 0.25% were injected into the lower surface of the chondrium. The same
process will be repeated for the other side.

In (Group B):

Patients were placed in the lateral decubitus position for block performance. The probe
in a sterile sleeve was applied 1-2 cm lateral to the midline to identify the
11-transverse process by counting upward from the sacrum region. After identifying the
erector spinae muscle and transverse processes, a 22- gauge, 50 mm nerve block needle
were advanced into the target interfacial plane in the craniocaudal direction using the
in-plane technique. After confirming the needle placement, 0.4 ml/kg bupivacaine 0.25%
were injected. ESPB was considered successful by the linear spread craniocaudally between
the tip of the transverse process and the erector spinae muscle. The same process was
repeated for the other side.

Postoperative:

Finally, patients were discharged to post anesthesia care unit (PACU). Postoperative pain
was assessed by FLACC score Figure 14. A multi-modal analgesic protocol was used for all
patients in all groups in the form IV paracetamol 1gm every 6 hrs. Pain intensity was
assessed using the FLACC scale which included categories for Face, Legs, Activity, Cry,
and Consolability, rated from 0 (no pain) to 10 (maximum pain) at 0.5, 1, 2, 4, 6, 8, 12,
and 24 h postoperatively (87). Rescue analgesia of morphine was given as 0.05 to 0.1
mg/kg bolus if the FLACC scale ≥ 4. The maximum dose of morphine was0.2 mg/kg.

Ethical consideration:

Informed consent was obtained from all parents whose children involved in the study.
There were adequate provisions to maintain the privacy of participants and
confidentiality of the data are as follows:

- The patients were given the option of not participating in the study if they did not
want to.

- We put code numbers to each participant with the name and address kept in a special
file.

- We hid the patients' names when we use the research.

- We used the results of the study only in a scientific manner and not to use it in
any other aims.

Sample size calculation:

The sample size calculation was done by G*Power 3.1.9.2 (Universitat Kiel, Germany). We
performed a pilot study (5 cases in each group), and we found that the mean (± SD) Time
to first analgesic was 8.2±3.42h in Group ESPB and 4.6±2.7h in Group M-TAPA. The sample
size was based on the following considerations: 1.168 effect size, 95% confidence limit,
95% power of the study, group ratio 1:1, and 4 cases were added to each group to overcome
dropout. Therefore, we recruited 25 patients in each group. Statistical analysis
Statistical analysis was done by SPSS v26 (IBM Inc., Chicago, IL, USA).Shapiro-Wilks test
and histograms were used to evaluate the normality of the distribution of data.
Quantitative parametric variables were presented as mean and standard deviation (SD) and
compared between the two groups utilizing unpaired Student's t- test. Quantitative
non-parametric data were presented as median and interquartile range (IQR) and were
analyzed by Mann-Whitney test. Qualitative variables were presented as frequency and
percentage and were analyzed utilizing the Chi-square test or Fisher's exact test when
appropriate. A two tailed P value < 0.05 was considered statistically significant.