Evaluation of the effect of transversus thoracic muscleplane block and serratus intercostal plane block on postoperative pain in patients undergoing off-pump coronary artery bypass grafting surgery under ultrasonography

Off-pump coronary artery by-pass grafting surgery (CABG); coronary artery surgery in the beating heart without using a cardiopulmonary by-pass (CPB) device. It is usually performed using the median sternotomy method. It is a very painful procedure as it is a major surgery. Postoperative analgesia methods are very important both to reduce pain and to prevent pain-related complications. Multimodal analgesia methods are often preferred. Transverse thoracic muscle plane block (TTMPB) and serratus intercostal plane block (SIPB) are among the preferred thoracic wall fascial blocks with the increasing use of ultrasound in recent years. Although TTMPB is sufficient for sternal region pain, it sometimes fails to provide adequate analgesia for chest tube pain inserted in the lateral chest region. In this case, adequate postoperative analgesia can be provided by adding SIPB to TTMPB. Although there are studies on the effectiveness of TTMPB in coronary artery bypass surgery in the literature; There are no studies on the combined use of TTMPB and SIPB. Based on this situation, we evaluated the effect of the combined use of TTMPB and SIPB on postoperative pain in our study. After the approval of the Local Ethics Committee dated 08/06/2021 and numbered 2021/149 and the written consent of the patients, 60 patients with ASA IIIII risk between the ages of 18-70 who were planned for elective off-pump coronary artery by-pass grafting surgery were included in the study. The patients were divided into 3 groups as Group T (TTMPB), Group T+S (TTMPB+SIPB) and Group K (Control) by randomized, prospective and closed envelope method before the operation. During the follow-up period, 2 patients were excluded from the study. After the standard operation was completed and the thorax was closed, SIPB was applied postoperatively with 20 ml of 0,25% bupivacaine bilaterally to the patients in Group T, and 10 ml of 0,25% bupivacaine in addition to the patients of Group T+S. No procedure was applied to the patients in Group K. Postoperatively, patients in all three groups received parol 1 gr IV (paracetamol 10 mg/ml) 4x1 and tramadol HCL 1 vi mg/kg (max 100 mg) (Tramosel 100 mg/2ml Haver Pharma İlaç A.Ş, Istanbul) 4 doses were administered at 0., 6., 12. and 18. hours. After the operation, each patient was intubated in the intensive care unit (ICU) and extubation was performed. Extubation time of the patients, visual analogue scale (VAS) values, systolic arterial pressure (SAB), diastolic arterial pressure (DAP), mean 1st, 2nd, 4th, 8th, 12th, 18th and 24th hours after extubation arterial pressure (MAP), heart rate (HR), SpO2, additional rescue analgesia consumption (Morphine HCL) at 0- 1, 1-12 and 12-24 time zones, and patient satisfaction level before discharge were recorded. Age was statistically significantly lower in Group T+S than in Group K (p<0,05). When the mean blood pressures were compared, Group T+S compared to Group K at the 1st, 2nd and 4th hours after extubation; Group T was found to be statistically significantly lower than Group K at the 4th hour (p<0,05). When the VAS scores between the groups were compared, it was found that Group T and Group T+S were statistically significantly lower than Group K at the 1st, 2nd, 4th, 8th, 12th, 18th and 24th hours after extubation (p<0,05). The VAS scores of Group T+S at the 1st, 2nd, 4th and 8th hours after extubation were found to be statistically significantly lower than the VAS scores of Group T (p<0,05). As a result; In our study, we found that the combination of USG-guided TTMPB and SIPB techniques in patients with elective off-pump CABG surgery decreased postoperative VAS scores, decreased morphine consumption and mean blood pressure as rescue analgesia, and increased patient satisfaction. Keywords: Coronary Artery By-pass Grafting Surgery, Postoperative Pain, Serratus Intercostal Plane Block, Transversus Thoracic Muscle Plane Block.