A 41-year-old woman (weighing 68 kg, 157 cm tall) with a previous history of childhood asthma became pregnant during follow-up of breast cancer. She was scheduled to undergo total mastectomy with sentinel lymph node biopsy at 18 weeks of gestation. In order to minimize physiological stress on both mother and fetus during the perioperative period, we decided to administer general anesthesia combined with continuous ESP block.
Her physical examination and preoperative laboratory tests indicated no abnormalities. After establishing standard monitoring, including bispectral index (BIS) and neuromuscular monitoring, general anesthesia was induced with intravenous propofol (target-controlled infusion [TCI] of 3.3 μg/mL) and remifentanil (0.25 μg/kg/min). Following calibration of the train-of-four (TOF) monitor, we administered rocuronium at fractional doses of 10 mg until the required degree of muscle relaxation was achieved. Tracheal intubation was uneventfully performed.
After placing the patient in the right lateral position, a high-frequency linear ultrasound transducer (LOGIQe, GE Healthcare, Wauwatosa, Wisconsin) was aseptically placed on the patient’s back in a longitudinal parasagittal orientation approximately 3 cm from the midline. The erector spinae muscles were identified superficial to the tip of the T3 transverse process. An 18-gauge, 100-mm needle (Contiplex® S Ultra, B. Braun, Melsungen, Germany) was inserted using an in-plane approach and in a cranial-to-caudal direction to contact the tip of the T3 transverse process (Fig. 1). The location of the needle tip was confirmed by visible fluid spread resulting in the lifting of the erector spinae muscles. A total of 20 mL of 0.25% levobupivacaine was injected through the needle, followed by insertion of a 19-gauge catheter 5 cm beyond the needle tip. Then, an infusion of 0.25% levobupivacaine into the erector spinae plane was started at the rate of 6 mL/h. General anesthesia was maintained with propofol (TCI of 3.0–3.3 μg/mL) to keep the BIS between 40 and 60, remifentanil (0.05–0.1 μg/kg/min) to maintain systolic blood pressure within 20% of preoperative values, and intermittent administration of 10 mg rocuronium to keep TOF counts below 2. The operative time was 111 min. The patient’s hemodynamics remained stable during the surgery. One thousand milligrams of acetaminophen was intravenously administered 15 min before the end of surgery. After full recovery from general anesthesia, the patient was extubated and transferred to the general ward of the department of surgical oncology.
Postoperative pain was measured using a numerical rating scale (NRS; an 11-point scale, 0 was no pain and 10 was the worst pain imaginable) immediately after recovery from general anesthesia and at varied intervals postoperatively (at 2, 6, 24, and 36 h). NRS scores remained at 1 point throughout the postoperative period, indicating minimal pain. At 2 h after surgery, postoperative assessment of the fetus with Doppler ultrasound revealed no abnormalities. The catheter of the ESP block was removed at 24 h after surgery. Postoperative pain did not worsen after termination of the block. The patient did not need any additional analgesics during the postoperative period and was discharged home on the 15th day after surgery with no adverse effects on either mother or fetus.