The main purpose of this study is to evaluate the impact of continuous 24-hour intravenous infusion of lidocaine on the incidence of PPCs in patients undergoing emergency laparotomy for intra-abdominal infection (IAI).The secondary objectives of this study are to assess the impact of continuous 24-hour intravenous lidocaine infusion on the proportion of patients requiring mechanical ventilation, protection of important organ function during the perioperative period, length of hospital stay, and outcomes within 30 days postoperatively.

PPCs are defined as the occurrence within 2 days postoperatively of atelectasis unplanned ventilation, acute respiratory distress syndrome (ARDS), and postoperative pneumonia syndrome Unplanned ventilation postoperatively: Defined as the use of non-invasive mechanical ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation (ECMO) after the first extubation postoperatively or if extubation cannot be performed as planned.

Acute Respiratory Distress Syndrome (ARDS): Defined as acute diffuse inflammatory lung injury leading to increased pulmonary vascular permeability, increased lung weight, loss of aerated lung tissue, hypoxemia, and bilateral opacities on imaging (using the Berlin Consensus definition).

Postoperative pneumonia: Defined according to the diagnostic criteria in the "Chinese Adult Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia Diagnosis and Treatment Guidelines" (2018 version): new or progressive infiltrates, consolidation, or ground-glass opacities on chest X-ray or CT, along with two or more of the following clinical symptoms: ① fever (> 38.0°C), ② purulent respiratory secretions, ③ peripheral blood leukocyte count > 10×10^9/L or < 4×10^9/L.

Inclusion Criteria:

• Age >18 years, any gender.
• Patients suspected of digestive tract perforation or obstruction based on physical examination, confirmed by imaging, requiring emergency surgical treatment.
• The anesthesia method is general anesthesia
• I or the patient's family have carefully read and signed the informed consent form
• Serum procalcitonin (PCT) at inflammatory levels or leukocytosis (>12×109/L) or leukopenia (<4×109/L) or >10% naive leukocytes

Exclusion Criteria:

• Have a history of local anesthesia drug allergy
• Pregnant patients
• Patients receiving renal replacement therapy
• Patients with arrhythmias or heart failure (second or third-degree atrioventricular block or left ventricular ejection fraction（LVEF）
• Preoperative platelet count<80 × 109/L
• Patients who require secondary surgery for postoperative anastomotic fistula
• Patients who have participated in other clinical studies