Ultrasound-guided erector spinae plane block
ESPB
After the induction of general anesthesia, the patients were placed in a standard lateral position to apply ESPB under aseptic conditions. All the blocks were performed by a senior anesthesiologist with extensive experience in ultrasound-guided nerve blocks. A high-frequency linear ultrasound probe was first placed longitudinally 3 cm from the midline of the T5 level of the spine. An in-plane technique was then used after imaging the trapezius, rhomboid major, erector spinae, and T5 transverse processes. The ESPB procedure entailed injecting local anesthetics deep into the erector spinae muscles and between the transverse processes in the fascial plane. Thereafter, a 22-G, 80-mm needle was inserted in a caudal to the cephalad orientation under ultrasound guidance after standard skin disinfection. The correct position of the needle tip was confirmed by injecting 2 mL of 0.9% normal saline that separated the transverse process from the erector spinae muscle. After determination of the correct needle tip position, the anesthesiologist slowly injected 30 ml of 0.5% ropivacaine, with or without administering the different doses of Dex.