The goal of this clinical trial is to learn if an ultrasound-guided nerve block called QLESP works to reduce pain and the need for strong pain medicines after robotic kidney surgery in adults. The main questions it aims to answer are:

1. Does QLESP reduce the total amount of opioid pain medicine participants need in the first 48 hours after surgery?
2. Does QLESP lower pain scores and improve recovery quality after surgery? Researchers will compare participants who receive QLESP block to participants who receive the same numbing medicine injected only at the surgical wound sites.

Participants will:

1. Be randomly assigned to receive either QLESP or local wound injection before surgery.
2. Have a patient-controlled pain pump for 48 hours after surgery.
3. Complete pain scores and recovery quality questionnaires at 2, 6, 12, 24, 48, and 72 hours after surgery.
4. Be followed until hospital discharge.

Inclusion Criteria:

• Aged 18 to 75 years
• Scheduled for elective robot-assisted partial nephrectomy (RAPN)
• American Society of Anesthesiologists (ASA) physical status I to III
• Body mass index (BMI) 18 to 35 kg/m²
• Voluntarily signed informed consent form Able to understand pain scoring and use of patient-controlled analgesia (PCA)

Exclusion Criteria:

• Language, communication, or comprehension barriers
• Infection at the intended puncture site
• Coagulopathy or bleeding diathesis
• Known allergy or contraindication to local anesthetics or opioids
• Use of analgesic medications within the past 3 months
• Peripheral neuropathy
• Severe cardiac, hepatic, or renal dysfunction
• Pregnancy or breastfeeding
• Refusal to participate in the study

The study protocol and informed consent form did not include provisions for secondary data analysis by external researchers.

This is a double-blind trial. Participants are blinded to group allocation through standardized pre-procedure communication and identical positioning, preparation, and needling sensation across both groups. Postoperative outcome assessors are blinded and do not have access to the randomization system or block procedure records; data are collected using uniform time windows. The anesthesiologist performing the block is not blinded due to the nature of the intervention but does not participate in postoperative follow-up or outcome assessment. The intraoperative anesthesia manager is blinded to group assignment and does not review block records. The statistician will remain blinded until database lock. The surgeon performing local wound infiltration in the control group is not involved in the randomization or block procedure.