Laparoscopic appendectomy with modified ERAS protocol group Preadmission. Not available due to the emergency setting. Preoperative care.

1) Patient brochure with a detailed description of the type of pathology, surgery procedure, rehabilitation process, possible complications, and other.

Surgery.

1. Low pressure (8-9 mmHg) pneumoperitoneum.
2. Routinely remove of appendix mesentery in presence of any signs of its inflammation.
3. Additional local anesthesia with 0.25% ropivacaine.
4. Abdominal cavity draining only in patients with perforated appendicitis and diffuse peritonitis (Gomes 5).

Postoperative care.

1. Early mobilization (2 h after surgery)
2. Early fluid intake (2 h after surgery)
3. Early liquid food (6 h after surgery)

Standard care laparoscopic appendectomy. Preadmission. Not available due to emergency setting. Preoperative care. 1) Patient oral informing about the type of pathology, surgery procedure and possible complications. No brochure.

Surgery.

1. Standard pressure (12-14 mmHg) pneumoperitoneum
2. Abdominal draining for patients with perforated and not perforated appendicitis complicated by abscess, local or diffuse peritonitis (Gomez ≥ 3A).
3. Appendix mesentery removing in the appearance of its necrotic changes.
4. No intraabdominal anesthesia. Postoperative care.

1) Mobilization in 4-6 h after surgery 2) Fluid intake in 6 hours 3) Liquid food intake in 12 hours

Preoperative care in both arms. Crystalloid isotonic solutions and antibiotic prophylaxis 30 min prior to surgery.

Surgery. General anesthesia with strict control of fluid therapy and hemodynamic changes during surgery. Appendectomy with the use of monopolar coagulation by experienced surgeons following appendix stump ligation by two Roeder knots.

Postoperative care. Antibiotics for 3-5 days for patients with complicated appendicitis (Gomez ≥ 3A). The postoperative pain level evaluation in rest by VAS in 0 h (immediately after awakening), 2, 6, 12 and 24 h postop. The postoperative analgesic modality "on demand": Ketorolac 30 mg for patients with VAS pain level ≥ 5 cm. Antiemetics in dyspepsia. No iv infusions postoperatively. Intestinal peristalsis evaluation by auscultation every 2 h after surgery.

Time interval measured from the end of the surgery until the moment of discharge from the hospital, measured in days

Number of patients who develop postoperative complications (surgical site infections, intraabdominal organ-specific infection, postoperative ileus) in relation to the total number of patients, measured in percentage