Onset of Sensory Block After Thoracic ESP Block

"The ESPB will be performed at the T4 level, monolaterally (according to the surgical side), with 30ml volume of 0.5% Ropivacaine injected with a 20-gauge, 50-mm-long needle. The technique used is the standard ultrasound-guided, sterile procedure.~Soon after performing the block, a timer will be started to mark the time for subsequent evaluations. At 1,3,5 and after every 5 minutes following the block until 40 minutes or until general anaesthesia is induced, the cold sensitivity of the chest will be explored."