covid interrupted initial start, then trainees involved finished program and no one took it on

The quadratus lumborum has since 2016 become standard of care for abdominal and retroperitoneal surgeries at UPMC-Shadyside Hospital, replacing paravertebral blocks, and as part of a broader multimodal analgesia institutional Enhanced Recovery After surgery protocol. Since the first description of this technique, several approaches to and anatomic targets within the quadratus lumborum plane have been described although their mechanism of action, spread, and relative clinical effectiveness remain areas of some debate. What is proposed here is to investigate the relative clinical effectiveness of the relationship high volume/low concentration of local anesthetic or low volume/ high concentration of local anesthetic.

Inclusion Criteria:

1. Patients 18-90 years old
2. Patients undergoing nephrectomy
3. Body Mass Index 19-36
4. Male and Female
5. All races
6. American Society of Anesthesiologist scale I, II, III

Exclusion Criteria:

1. Patient refusal
2. Pregnancy
3. Non-English speaking or inability to participate in the study
4. Patients with coagulopathy or With International Normalized Ratio >1,5 the day of the surgery.
5. Chronic steroid use
6. Chronic pain
7. Chronic opiate use

there is no plan to share individual participant data.

Randomization will be performed with software excel or spss. This randomization will be kept in an envelope. After the patient consents participation in the study, the investigator and the care provider will open the envelope and will perform the block according to the established in the randomization. The patient or the outcomes assessor will not have access to the volume and concentration used during the block. Will be the responsibility of investigators to keep in a safe place the information about the block received by the patients.