Randomization and grouping
ESPB
Block randomization was applied to the study. Random blocks were created for patients. Treatments were designated as O (One-Level) and B (Bi-Level). One block consisted of six randomly ordered treatment assignments (OOBOBB, BOBOOB, etc.). As patients entered the trial, they received the next treatment in the current block. This study consisted of blocks of six patients, and the number of patients assigned to two treatments in a block was never more than three. Thus, patients were randomly assigned to two groups of 30 individuals each, with an allocation ratio of 1:1. Group I included those to be administered One-Level ESPB and Group II included those to be administered Bi-Level ESPB.