Intravenous lidocaine - a potent local anesthetic with analgesic and anti- inflammatory properties has been shown to be an effective adjunct that reduces intra and postoperative opioid consumption and facilitates pain management in adults. In children population promising but limited evidence is available. The study has been planned to evaluate the efficacy of continuous intravenous infusion of lidocaine in alleviation of hemodynamic reaction to tracheal intubation, as well as metabolic and hormonal response to laparoscopic procedure in children.

Laryngoscopy and endotracheal intubation are associated with noxious stimulation. Exacerbated circulatory system response may present as hypertension or arrhythmias including cardiac arrest. A sudden change in hemodynamic status connected with painful stimulation may precipitate deterioration in cerebral blood flow, especially in patients with intracranial hypertension (traumatic brain injury, intracranial hemorrhage, active hydrocephalus, etc). Many interventions have been applied to attenuate harmful hemodynamic reaction. One of them is intravenous lidocaine infusion. According to available data lidocaine is superior to placebo in attenuating systolic, diastolic and mean arterial pressure changes in children. Our study will focus on assessing hemodynamic stability preserving properties during induction of anesthesia and tracheal intubation. Blood pressure will be recorded and analyzed. The secondary aim is to examine intravenous lidocaine infusion in terms of reducing systemic response to surgical stress. Cortisol and glucose levels will be measured before skin incision, and immediately after the end of surgery. Side effects and serum lidocaine levels will be recorded to determine safety of the examined intervention. Similar pattern of infusion was investigated in RCT concerning children population - the toxic plasma level of 5 mcg/ml was not reached. Studies on children population have promising results but high quality randomized controlled trials are still missing. The proposed study has been planned to evaluate the efficacy of continuous infusion of lidocaine as an adjunct to standard general anesthesia (involving intravenous induction and opioid with sevoflurane maintenance) in attenuating hemodynamic reaction to tracheal intubation, as well as metabolic and hormonal response to surgical procedure in children undergoing laparoscopic appendectomy.

Inclusion Criteria:

• ASA physical status class 1E, 2E, 3E;
• Patients undergoing laparoscopic appendectomy.

Exclusion Criteria:

• Allergy to local anesthetics or contraindications for the use of lidocaine;
• ASA physical status class 4E or higher;
• Severe cardiovascular disease;
• Preoperative bradycardia;
• Preoperative atrioventricular block;
• Renal failure;
• Chronic treatment with analgesics;
• Legal guardians' refusal.

The datasets used and/or analysed during the study will be available from the corresponding author on reasonable request.

The study protocol will be available to other researchers continuously after its publication.

The CSR will be hopefully publicated after the study completion.

The datasets used and/or analysed during the study will be available from the corresponding author on reasonable request.

The drug or placebo(normal saline) will be placed in a syringe by the principal investigator. Only principal investigator will be aware of the participants allocation. The principal investigator will not be involved in the process of: recruitment, providing an intervention, or outcomes assessment.