炎症性腸疾患（IBD）患者における脊柱起立面（ESP）ブロックの有効性

Work Plan: This prospective trial would include Inflammatory Bowel Disease (IBD) patients undergoing laparoscopic or laparoscopic assisted abdominal surgery. Patients generally have pre-anesthetic visits 1-2 weeks prior to their scheduled operation. Patients identified by the clinical Research Study Assistant (CRSA) based on inclusion and exclusion criteria, will be approached regarding this study in the pre-anesthetic clinic. Patients will be made aware of the components of the study and the CRSA will be present to answer any questions. Patients will be allocated at random to receive ultrasound guided (Erector spinae plane) ESP block either with the local anesthetic of 0.5% of Ropivicane 20 mL bilaterally (intervention group) or normal saline (control group) before surgery which will take 5-10 minutes in a 1:1 ratio. Anesthesiologist and patients will be blinded of the allocation. Allocation sequence will be concealed using opaque, sealed, consecutively numbered envelopes. Written informed consent will be obtained from all participants after confirmation of eligibility. Baseline measurements will be made by the CRSA in the pre-anesthetic Clinic. The study coordinator will collect the data once a day for maximum 10 minutes each time up to 3 days postoperatively. There will be a virtual (via telephone) follow up data for quality of life (QoL) at "6 weeks" post-discharge. Sample Size: Sample size justification was based on the primary outcome, QoR15, and the primary objective. According to the previous report10 and our preliminary data, the mean (std) of the total score of QoR15 (quality of recovery) was conservatively assumed as 98 for patients in control group. The investigators estimated a sample size of 84 (42 per group) will achieve 80% power to detect an absolute 10 point increase in total score of QoR15 for patients in intervention group compared to the control group. A two-sided two-sample equal-variance t-test was used for the power analysis assuming a significance level of 0.05. To account for possible 5% lost follow up, the investigators will recruit a total of 90 patients for this study.

Performance of ESP block: Patient Selection. A thorough history, physical exam, and informed consent are carried out. Altered mental status, concomitant injuries, and intubation/ ventilation are considerations primarily with regard to the ability to position the patient safely and access the Paraspinal area to perform the block. The investigators do not view coagulopathy or the use of anticoagulants or antiplatelet drugs as absolute contraindications to ESP block because the theoretical risk of clinically significant hemorrhage or hematoma is very low; however, an individualized risk-benefit assessment should be performed for every patient. Block Equipment and Preparation. In the majority of patients, the investigators will use a high-frequency (10-15 MHz) linear-array transducer because it provides a higher-resolution image; however, a low-frequency (5-2 MHz) curvilinear probe is useful in more obese patients where the transverse processes lie at a depth greater than 4 cm. The block is performed before induction of anesthesia with full aseptic precautions, and the usual precautions for any regional anesthesia procedures will be applied. Scanning Technique. After patients are positioned optimally (sitting or lateral decubitus), the affected area is identified along with the target transverse process. The ultrasound transducer is placed in a longitudinal parasagittal orientation, about 3 cm lateral to the spinous processes, allowing for visualization of adjacent transverse processes (TP) in an in-plane approach. These are recognizable as flat, squared-off acoustic shadows with only a very faint image of the pleura visible. After correct TP identification, an 22-gauge echogenic needle (Pajunk E-Cath, Pajunk Medical Systems) is inserted using an in-plane, cranial-to-caudal approach to contact the bony shadow of the TP with the tip deep to the fascial plane of the erector spinae muscle. The correct location of the needle tip is confirmed by injecting 0.5-1 ml of normal saline 0.9% and observing linear fluid spread lifting the erector spinae muscle off the tip of the TP. Once the fascial plane is recognized, 20 mL of ropivacaine 0.5% is injected and cranial and caudal spread of local anesthetic can be visualized.