The aim of this clinical trial is to investigate the effect of different injection speeds on the spread of local anesthetic during ultrasound-guided erector spinae plane block (ESPB) in patients undergoing CT-guided lung nodule localization. The primary question addressed is whether a high injection speed (30 ml delivered within 30 seconds) produces a different local anesthetic distribution compared with a lower injection speed (30 ml delivered within 180 seconds).
aged 18-80 years
BMI 18-30 kg/m²
ASA classification I-III
Allergy to the study drug or to local anesthetics
History of opioid abuse
Previous infection at the ESPB or PVB puncture site
Peripheral neuropathy