Evaluation of the effect of ultrasound-guidedmidpoint transverse process to pleura block on postoperative pain inpatients undergoing breast surgery

Breast cancer is the most common cancer in women and its incidence has been increasing in the last decade. Despite recent advances in breast cancer surgery, postoperative side effects such as nausea, vomiting and postoperative pain are common. Thoracic paravertebral blocks (TPVB), one of the regional anesthesia techniques that are increasingly used today, have been found to provide perioperative analgesia in breast surgeries and reduce the risk of postoperative nausea and vomiting. However, complications such as pneumothorax and neuraxial spread remain a concern even when performed under ultrasound guidance. Costache et al defined the Midpoint Transverse Process to Pleura (MTP) to avoid such possibilities. In this study, we aimed to evaluate the effectiveness of preoperative MTP block on postoperative analgesia and opioid analgesic use in patients who will undergo unilateral breast surgery. After the permission of the Local Ethics Committee dated 08/02/2022 and numbered 2022/18 and the written consent of the patients, 40 patients with ASA III risk between the ages of 18-70 who were planned for breast surgery were included in the study. The patients were divided into 2 groups as Group M (MTP) and Group K (Control) by randomized, prospective and closed envelope method before the operation. After intubation, thoracic vertebra (T) levels were determined by placing the patients in Group M in a lateral position, and by applying 10 ml of 0.25% bupivacaine to each level separately by ultrasound to the levels of T2-3, T4-5, T6- 7; with a total of 30 ml of 0.25% bupivacaine (Buvasin %0,5 Vem İlaç İstanbul, Türkiye), MTP block was applied. No invasive procedure was performed in Group K. In both groups, continuous opioid infusion at 4 mg/ml concentration of 2 cc/hour, maximum 400 mg dose in 24 hours with intravenous (IV) Tramadol HCL (Tramosel 100 mg/2 ml Haver Pharma İlaç A.Ş, Istanbul) with Patient Controlled Analgesia (PCA) after the operation. With a lock-in interval of 20 minutes, doses that could be given IV bolus 20 mg tramadol HCL were administered each time the patient pressed the button. Visual Analogue Scale (VAS) values at 0, 1, 2, 4, 8, 12, 18, and 24 hours after extubation, analgesic consumption, nausea, vomiting and itching at 0-1, 1-12, 12-24 hours. Total analgesic consumption and patient satisfaction were evaluated and recorded. There was no significant difference between the groups in demographic data. In the VAS evaluation of the patients, it was determined that the VAS values at the 0th, 1st, 2nd and 4th hours after postoperative extubation were statistically significantly lower in Group M compared to Group K (p<0.05). It was observed that the total amount of tramadol consumption was statistically significantly lower in Group M (p<0.05). Heart rate (HR) at the 1st hour, systolic blood pressure (SBP) and diastolic blood pressure (DBP) at the 1st and 2nd hours were significantly lower in Group M. When examined in terms of side effects, nausea was found to be significantly lower at 0-1 hour in Group M. In conclusion; We found that MTP block applied in breast surgery, as a part of multimodal analgesia, reduces analgesic consumption and provides effective postoperative analgesia.