comparison of different local anesthetic dose in suprascapular and axillary blocks in shoulder arthroscopies

Conditions: Pain, Postoperative

Summary: the research is designed as a single-center, prospective, randomized double-blind study. the patients undergoing shoulder arthroscopy surgery in istanbul university, istanbul faculty of medicine, department of orthopedics and traumatology will be included. patients who are legally authorized to make decisions on their behalf will be informed about the research and their written consent will be obtained. patients who do not give consent will be excluded. ultrasonography (usg) guided combined suprascapular and axillary block will be performed routinely for postoperative analgesia. after the block is performed, general anesthesia will be applied. the patients will be divided into 4 groups. three different doses of local anesthetic will be given to patients (30 cc vs 20 cc vs 10 cc). local anesthetic dose will be the same for suprascapular and axillary blocks. the fourth group will be sham control. pain score will be determined by visual pain scoring (vas) and analgesic consumption will be provided by the use of a patient controlled analgesia (pca) device with intravenous morphine applied in routine practice to all four groups at the postoperative 1, 4, 8,12 and 24 hours. patient will be observed for postoperative nausea and vomiting, first time to mobilization, length of hospital stay, analgesic consumption and satisfaction of surgeon and patient.

the investigators research was designed as a single-center, prospective, randomized double-blind study. after the approval of the ethics committee, the study will start and is aimed to be completed in 6 months. the patients consecutively undergoing shoulder arthroscopy surgery in istanbul university istanbul faculty of medicine, department of orthopedics and traumatology will be included. patients who are legally authorized to make decisions on their behalf will be informed about the research and their written consent will be obtained. patients who do not give consent will not be included in the study. preoperative evaluation of the patients will include detailed history, demographic and clinical parameters including gender, age, indication for shoulder arthroscopy, creatinine, chronic disease history will be recorded. patients will be taken to the operating room after premedication with 2 mg midazolam and 50 mg fentanyl. patients will be monitored for rhythm, blood oxygen and pressure in the operating room. ultrasonography (usg) guided suprascapular and axillary block will be performed. suprascapular and axillary block will be done for postoperative analgesia. after the block is done, general anesthesia will be applied. in this study there will be four groups with the control group included. for the first group 15cc+15cc , for the second group 10cc+10cc for the third group 5cc+5cc of local anesthetic will be injected. the fourth group will be sham control. pain score will be determined by visual pain scoring (vas) and analgesic consumption will be provided by the use of a patient controlled analgesia (pca) device with intravenous morphine applied in routine practice to all four groups at the postoperative 1, 4, 8,12 and 24 hours. patients will be followed up for 48 hours postoperatively in routine practice. they will be observed for postoperative nausea and vomiting, first mobilisation time, lenght of hospital stay, analgesic consumption and surgent and patient satisfaction. before the study, it was determined that at least 132 patients should be collected in the power analysis performed with the help of similar literature data. after collecting the demographic data and morphine consumption data of the patients, statistical analysis will be performed with statistical package for the social sciences (spss). the investigators study does not contain any modifications other than the investigators daily routine practices.

Eligibility criteria:
inclusion criteria: * patients scheduled for total shoulder arthroscopy surgery * patients with american society of anesthesiology (asa) class 1-3 exclusion criteria: * refusal of regional anesthesia * infection on the local anesthetic application area * patients with known coagulopathy * known allergy against local anesthetics * anatomical difficulties to perform supra scapular and axillary blocks

Keywords: suprascapular nerve block axillary nerve block regional anesthesia analgesic consumption postoperative analgesia numeric rating scale