Impact of Administration of Esmolol on Nociception Level-guided Control of Nociception.

Inclusion Criteria: * Fully consented, American Society of Anesthesiologists Classification Score 1-3 patients from 18yo to 65yo * Undergoing laparoscopic surgery associated with sub umbilical mini-laparotomy. Eligible surgeries will be hysterectomy (excluding vaginal approach) and left hemicolectomy, of duration time expected under 180 minutes, under general anesthesia * No allergy to one of the medications used in this study Exclusion Criteria: Contraindication to the use of the study drug (esmolol) is an exclusion criterion : * Hypotension * Sinus bradycardia * Sick sinus syndrome * Second and third degree A-V block * Pulmonary hypertension * Right ventricular failure secondary to pulmonary hypertension * Decompensated heart failure * Cardiogenic shock * Nontreated pheochromocytoma * Known hypersensitivity to esmolol or any of the inactive ingredients of the product * Allergy to esmolol or other beta blockers (cross-sensitivity is possible) * Renal dysfunction * Airway disease such as asthma or chronic obstructive pulmonary disease * Thyrotoxicosis * Myasthenia gravis * Raynaud's disease or peripheral circulatory disorder Other situations leading to exclusion : * Severe mental impairment * Chronic use of opioids, β-adrenergic receptors antagonists * High risk of conversion to laparotomy according to the surgical team (\>25%) Patients will automatically be excluded after recruitment if they withdraw their consent, or if laparoscopy is converted to laparotomy.