The goal of this observational study is to evaluate the quality of postoperative analgesia in a group of obese patients schedule to bariatric surgery under TIVA Opiod-free after to receive lidocaine and ketamine perfusion. The main question it aims to answer are: How lidocaine and ketamine perfusion during recovery period does impact over morphine consumption on the following 48 hours after surgery? All participants will receive total intravenous anesthesia and, at the end of the surgery, they will be divided in two groups, group A: placebo and, group B: with postoperative lidocaine and ketamine perfusion. Our hypothesis is ketamine and lidocaine are a good alternative to decrease the use of morphine in obese patients.

The obese patients have more risk for certain side effects and complications with elevated risk of perioperative mortality and morbidity. An effective postoperative pain management is important to prevent pulmonary complications and, it is not recommended continuous infusions of opioids in this kind of patients, because the opioid-induced upper airway obstruction and respiratory depression are more likely to be seen in obese patients with obstructive sleep apnea. We can reduce perioperative opioid using dexmedetomidine, ketamine and lidocaine, however, it is a little know the use and benefits of lidocaine and ketamine inmediately after surgery.

Inclusion Criteria:

• All patients between 18 y 65 years old.
• IMC > 30 kg/m2
• ASA II/III

Exclusion Criteria:

• Patients taking high doses of opioids before operation for chronic pain
• Patients with allergies to any study medication.
• Pregnancy or breastfeeding.
• Kidney or heptic failure.
• Surgical complication

Obese patient schedule to laparoscopic bariatric surgery since january 2022 until diciembre 2022 at Hospital HM Delfos Barcelona España.