The number of obese and overweighted persons doubled since 1980. They are 600 million in 2014 all over the world. Obesity results in anatomical, physiological and pharmacological changes which represent a challenge for every anesthetist. Difficult airway increases by 30% with obesity and so awake extubation are the preferred technique. Coughing can be alleviated by opioid receptors which play a role in the cough reflex. Remifentanil may be useful as an ultra-short acting opioid and its effect swiftly and predictably disappears after cessation. An emergence cough is attenuated by remifentanil administered via continuous infusion (TCI), and the expected effective effect-site concentrations investigated have ranged from 1.5 to 2.5 ng.ml/L.

The investigators designed this study to examine the effect of different small doses of Remifentanil on the incidence of cough reflex during emergence from anesthesia in obese patients undergoing bariatric surgery. The investigators will study if these small doses will delay the recovery of the patient or not. The other expected side effects will be observed eg. Respiratory depression. Time to the first painkiller required will be registered

Inclusion Criteria:

1. Age≥ 18 years
2. Subject has signed informed consent for bariatric laparoscopic surgery.
3. Subject must be ASA I or ASA II according to the American Society of Anesthetists classification.

Exclusion Criteria:

1. Age < 18 years.
2. Smoking patient.
3. Hypertension.
4. Bronchial asthma.
5. Obstructive sleep apnea syndrome.