Efficacy of Ultrasound-Guided Transversus Thoracic Muscle Plane Block on Postoperative Opioid Consumption After Cardiac Surgery: A Prospective, Randomized, Double-Blind Study.

OBJECTIVES: The postoperative analgesic efficacy of transversus thoracic muscle plane block (TTMPB) has not yet been evaluated sufficiently. This randomized controlled study evaluated the effect of TTMPB on postoperative opioid consumption in patients undergoing cardiac surgery. DESIGN: Prospective, randomized, double-blind study. SETTINGS: Single institution, academic university hospital. PARTICIPANTS: Forty-eight adult patients having cardiac surgery with median sternotomy. INTERVENTIONS: Patients were randomly assigned to receive preoperative ultrasound-guided TTMPB with either 20 mL of 0.25% bupivacaine or saline bilaterally. Postoperative analgesia was administered intravenously in the 2 groups 4 times a day with 1000 mg of paracetamol and patient-controlled analgesia with fentanyl. MEASUREMENTS AND MAIN RESULTS: The primary outcome was opioid consumption in the first 24 hours. Secondary outcomes included postoperative pain scores, first analgesic requirement time, rescue analgesia, intensive care discharge time, and side effects. Compared with the control group (median 465 µg, interquartile range 415-585), the transversus thoracic muscle plane (TTMP) group (median 255 µg, interquartile range 235-305) had reduced postoperative 24-hour opioid consumption (p < 0.001). Pain scores were significantly lower in the TTMP group compared with the control group up to 12 hours after surgery both at rest and active movement (p < 0.001). Compared with the TTMP group, the proportion of postoperative nausea and pruritus was statistically higher in the control group (p < 0.001). CONCLUSIONS: A single preoperative TTMPB provided effective analgesia and decreased opioid requirements in patients undergoing cardiac surgery.