Ketamine vs Hydromorphone

This study will help to determine if investigators can minimize narcotic use in laparoscopic gastric bypass patients while maintaining adequate pain control. This will allow investigators to minimize the negative side effects of narcotics which is a goal in this population.

The study will be a head to head observational study of patients who have undergone gastric bypass surgery. The methods of intraoperative anesthesiology will be Ketamine or Narcotic. Both are FDA approved methods of delivering anesthesia. The amount of narcotics a patient receives is part of the medical record post-operatively will be followed from post-anesthesia care unit (PACU) through to discharge. The amount of narcotics needed to control the patient's pain (converted to morphine equivalent units) and pain scores (a hospital standard measure) will be collected for 48 hours for the study, or until discharge, whichever occurs sooner. The conversion to a morphine equivalent unit allows investigators to compare different narcotics the patient may receive in a more standardized way. The results will be analyzed and compared between the two groups.

This group will receive intraoperative narcotics as is usually done for this surgery. This arm will not receive Ketamine.

This group will receive an intraoperative infusion of ketamine rather than narcotics to control pain.

Used to translate the dose and route of each of the opioids the patient has received over the last 48 hours to a parenteral morphine equivalent using a standard conversion table. SD standard deviation, mg: milligrams, pain measured on a 0-10 scale

Inclusion Criteria: Obese patient presenting for laparoscopic gastric bypass between 18 and 65 years of age Exclusion Criteria: Hypersensitivity, allergy, or contraindications to fentanyl, propofol, or ketamine.