The Effect of Bupivacaine Liposome Combined With Bupivacaine Hydrochloride on Thoracic Paravertebral Nerve Block for Postoperative Pain After Thoracoscopic Lung Surgery

Standard monitoring, including electrocardiography (ECG), heart rate (HR), noninvasive blood pressure (NIBP), pulse oxygen saturation (SpO2), end-tidal carbon dioxide (ETCo2), and bispectral index (BIS) was initiated on arrival in the operating room. A neuromuscular monitor (JS-100, Beijing SLGO Medical Technology Co., Ltd., China) was used to confirm neuromuscular block (NMB).

Intravenous anesthesia was induced with 0.04 mg/kg midazolam, 0.3-0.5 μg/kg sufentanil, 1.5-2.5 mg/kg propofol, and 0.6 mg/kg rocuronium. Hemodynamics were supported with vasoactive agents (atropine, norepinephrine, dopamine, esmolol) as needed. After the train of four count (TOFC) ratio reached zero, a double-lumen tube or a single-lumen tube with a bronchial blocker was inserted, with correct positioning confirmed by fiberoptic bronchoscopy. Under real-time ultrasound visualization, a senior anesthesiologist performed thoracic paravertebral blocks at the T4-5, T6-7, and T8-9 levels in patients placed in the lateral decubitus position, injecting 6 mL, 8 mL, and 6 mL of local anesthetic at the respective levels.

Group B : Patients in the intervention group received a mixture of 10 mL of 1.33% liposomal bupivacaine (133 mg) and 10 mL of 0.5% bupivacaine hydrochloride,.

Group A: whereas those in the control group received 20 mL of 0.5% bupivacaine hydrochloride (total dose, 100 mg).

All patients received total intravenous anesthesia during surgery. Propofol was administered at a rate of 2-4 mg/kg/h, and remifentanil was administered at a rate of 0.05-0.3 μg/kg/min to maintain a BIS value range from 40 to 60. Rocuronium will be administered and adjusted to achieve deep NMB (defined as a TOFC=0 and a post-tetanic count =1-2). Standard ventilation parameters included a respiratory rate of 10-12 breaths·min-¹ and a positive end-expiratory pressure (PEEP) of 5cmH₂O. During double-lung ventilation, a tidal volume of 8 mL/kg was used, with ETCo2 maintained between 35-45 mmHg and peak airway pressure kept below 20cmH₂O. During single-lung ventilation, the tidal volume was reduced to 6 mL/kg, with ETCo2 maintained below 60 mmHg and peak airway pressure kept below 30cmH₂O. Intravenous sufentanil (0.15 μg/kg) and ondansetron hydrochloride (8mg) were administered prior to the end of surgery. After surgery, patients were transferred to the post-anesthesia care unit (PACU) for further monitoring. Additionally, 2-4 mg/kg of sugammadex was given to reverse the residual effect of rocuronium.