A 62-year-old man (175.6 cm 75 kg) was scheduled for sternum closure using the right latissimus dorsi muscle flap for mediastinitis. He had gone CABG using the bilateral internal thoracic arteries 8 months before. He underwent debridement and vacuum-assisted closure (VAC) of the infected wounds 1 month after surgery. Although sternum closure using an omental flap was performed thereafter, debridement and VAC were reintroduced because of infection. His medical history included diabetes mellitus with end-stage diabetic nephropathy. He has been receiving hemodialysis, and the right lower leg amputated for diabetic gangrene. He was receiving linagliptin and mitiglinide calcium hydrate and aspirin. His laboratory data showed renal dysfunction (estimated glomerular filtration rate 6.2 ml/min) and anemia (hemoglobin 9.6 d/dl), but no abnormal coagulation was observed, and the platelet count was 145,000/μl. He also complained of postoperative nausea and vomiting (PONV) probably due to fentanyl after multiple anesthesia histories.
Considering the possibility of widespread surgical wound and he was taking aspirin, continuous ultrasound-guided ESPB was planned. Aspirin was continued until the day of surgery. He received no premedication. Standard monitoring and intra-arterial blood pressure monitoring were performed. General anesthesia was induced with propofol 70 mg, fentanyl 250 μg, and rocuronium 60 mg and maintained with 1.5% sevoflurane in an inhaled oxygen concentration of 60% with a total flow of 3 l/min and remifentanil 0.1–0.2 μg/kg/min. After tracheal intubation, he was placed in the left lateral decubitus position. After performing standard skin asepsis, the linear transducer (12 MHz, LOGIQ e; GE Healthcare, Chicago IL), within a sterile sleeve, was positioned on the patient in a transverse orientation and the T6 spinous process image was taken. The transducer was moved right laterally to identify the transverse process of T6 and then rotated 90° to visualize the right transverse process and the erector spinae muscles above it. A continuous nerve block set (Contiplex Tuohy Ultra set; B BRAUN, Melsungen, Germany) with an 18-G, 100-mm Tuohy needle was inserted in-plane in a caudal to cranial direction until contact with the right T6 transverse process was made. After confirming that there was no reverse blood flow, hydrodissection with 2 ml of 0.375% ropivacaine was used to confirm the correct needle tip position. Eighteen milliliters of 0.375% ropivacaine was injected, and a 20-G catheter was advanced through the needle. After injecting 20 ml of 0.375% ropivacaine again from the catheter 55 min after the initial injection, 0.2% ropivacaine was continuously infused at 5 ml/h before the start of surgery. Hemodynamic stability was achieved without the need for an additional bolus administration of fentanyl during surgery. One gram of acetaminophen was intravenously infused 30 min before the end of the operation. There were no other events of note during the operation. The operative time was 5 h and 49 min, and the anesthesia time was 8 h and 2 min.
After extubation in the operating room and admission to the intensive care unit (ICU), the nerve blockade area and Numerical Rating Scale (NRS) were confirmed when sufficient consciousness was reached. Regarding nerve blockade, the cold sign was T2–T8, pinprick was T3–T8, and NRS at rest was 1/10 immediately after surgery. The main pain area was the wound where the right latissimus dorsi muscle flap was collected, but pain of the median sternum wound was not noted. Acetaminophen at 500 mg was administered orally because the NRS temporarily increased to 7/10 due to body movement. However, the NRS at rest was 1–2/10 and that while active was 4/10. For pain during movement, 3 ml of patient-controlled analgesia (PCA) consisting of 0.2% ropivacaine was flushed, and this was performed twice in the ICU. After leaving the ICU 24 h after the operation and being transported to the general ward, pain was not aggravated and the ESPB catheter was removed 56 h after the operation. After removal of the catheter, oral administration of acetaminophen during pain provided good pain control. No ESPB-related complications were observed during ESPB catheter placement or after removal. Regarding PONV, nausea was observed immediately after admission to the ICU and only a single intravenous injection of 10 mg of metoclopramide was administered. Thereafter, the patient had no PONV.