Analgesic efficacy of Transverse thoracic muscle plane block (modified approach) in off-pump coronary artery bypass grafting : A retrospective cohort study

Abstract

Abstract Background:To investigate the safety and effectiveness of bilateral transverse thoracic muscle plane (TTP) block (modified approach) combined with general anesthesia in off-pump coronary artery bypass grafting (OPCABG). Methods :The clinical data of 60 patients undergoing OPCABG, selected from March to August 2021 in general hospital of northern theater command, were retrospectively analyzed and divided into TTP block with general anesthesia group ( group T, n=30) and general anesthesia group (group G, n=30) according to anesthesia mode. Patients in group T undergone bilateral TTP block (modified approach, 0.25% ropivacaine 20 ml each side) before anesthesia induction, and both groups were induced by routine anesthesia. The mean arterial pressure (MAP) and heart rate (HR) were recorded and analyzed before and after cutting, splitting and closing the sternum, and the total dosage of sufentanil at the end of operation was recorded. The levels of lactic acid and blood glucose were detected with blood gas analysis before the operation , at the end of the operation, and at 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 16 h, 20 h and 24 h after the operation. The visual analogue scale (VAS) scores in resting and moving state were recorded at 12 h, 24 h and 48 h after operation. The numbers of patients who were first added analgesic drugs (pethidine) on the day, the first day and the second day after operations were recorded, and the occurrence of postoperative adverse reactions was recorded. Results: Compared with group G, the change rate of MAP and HR in group T decreased slightly at each time point, but the difference was not statistically significant (P>0.05). The levels of lactic acid at 2 h and 4 h after operation and the levels of blood glucose at 2 h, 4 h and 6 h after operation were significantly lower than those of group G (P<0.05). Compared with group G, the VAS scores (resting and moving state) of group T significantly decreased at 12 h (resting state) after operation (P<0.05). Compared with group G , the extubation time of group T was shorter, but with no statistical significance (P>0.05); while the dosage of sufentanil in group T was obviously decreased, and the number of patients who were added analgesics at the postoperative day was markedly reduced (P<0.05). The incidence of postoperative chills was obviously lower in group T than in group G (P<0.05). No significant difference existed between the two groups in the incidence of postoperative nausea and vomiting, arrhythmia, pruritus, abdominal distention and infection in operation area 3 days post operation (P>0.05). Conclusion: Bilateral TTP block (modified approach) combined with general anesthesia can provide good perioperative analgesia for patient undergoing OPCABG, reduce the use of opioids, and inhibit the stress response to a certain extent, thus having better safety and effectiveness.