Comparison of Local Anesthetic Dose in Ipack Block Performed in Knee Arthroplasty Operations

The investigators research was designed as a single-center, prospective, randomized study.

The patients undergoing knee arthroplasty in Istanbul University Istanbul Medicine Faculty 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.

Patients will be evaluated preoperative before surgery, a detailed history will be taken and physical examination will be carried out. Medical and surgical resume information will be obtained. Patients' NRS scores will be recorded before the operation. Patients will be taken to the operating room after premedication.

ECG, pulse oximeter, blood pressure monitoring will be performed in the operating room. Patients will be given US guided IPACK and adductor blocks using a 22 gauge 10 mm block needle after compliance with the rules of asepsia and antisepsis in the supine position according to the group of patients in which they were included.

IPACK and adductor block will be done for postoperative analgesia. After then, a single dose of spinal anesthesia will be applied as a regional anesthesia method, in a sitting position, using the appropriate spinal needle, as is routinely applied in the investigators clinic. After the block is completed, the pinprick test will be done and the operation will be started after the successful completion of the block is confirmed. Oxygen will be given to the patients with a face mask at 4 lt / min throughout the operation.ECG, saturation, invasive / noninvasive blood pressure monitoring of the patients will be done.

In the investigators clinic, the use of IPACK block, adductor block and PCA (patient controlled analgesia) device with intravenous morphine for postoperative analgesia is routinely performed. In this study, four randomized groups will be formed together with the control group.Computer-generated random numbers will be used for simple randomization of patients.

IPACK block will be applied to the 1st group with 10 ml of 0.25% bupivacaine, to the 2nd group with 15 ml of 0.25% bupivacaine, and to the 3rd group with 20 ml of 0.25% bupivacaine.Adductor block will be applied to all the groups with 15 ml %0,25 bupivacaine and PCA (patient controlled analgesia) device with intravenous morphine for postoperative analgesia is performed.

Pain score and total morphine consumption will be determined by numeric rating scale (NRS) at the postoperative 1, 4, 8, 12, 24 and 48th hours by providing the use of a PCA device with intravenous morphine applied in routine practice to all four groups. As in routine practice, when NRS > 4 after each interrogation, morphine 2 mg iv will be administered as additional analgesia and the maximum will be increased to 10 mg. Pain management will continue when NRS < 4.

Patients are followed up in the service for 48 hours postoperatively in routine practice.

In the postoperative period, patients will be evaluated in terms of additional nausea and vomiting,amount of morphine consumed and additional analgesic need postoperative period up to 48 hours.First mobilization time, hospitalization time will be evaluated.Womac osteoarthritis index and joint range of motion will be evaluated at preoperative period and at the discharge day from the hospital.The Medical Research Council (MRC) Scale for Muscle Strength for lower extremity will be evaluated preoperative period, at postoperative 24th hour and at the discharge day from the hospital.

Postop patient satisfaction and surgical satisfaction with Likert scale will also be evaluated at postoperative period.

During the procedure, complications such as failed block, nerve damage, vascular injury, intravenous injection of local anesthetic, local anesthetic toxicity and allergic reactions will be recorded.

Before the study, it was determined that at least 112 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, the data will be transferred to the statistical program called SPSS and statistical analysis will be made.The investigators study does not contain any modifications other than the investigators daily routine practices.

Inclusion criteria

• Patients scheduled for knee arthroplasty surgery under regional anesthesia
• ASA(American Society of Anesthesiology) 1-3
• Receiving consent that accept regional analgesia

Exclusion criteria

• Refusal of regional anesthesia
• Infection on the local anesthetic application area
• Infection in the central nervous system
• Coagulopathy
• BMI > 40
• Known allergy against local anesthetics