Lack of Enrollment

Propofol is one of the most popular anesthetic drugs used for sedation during upper gastrointestinal endoscopies due to its quick onset and quick resolution of symptoms allowing patients to leave the hospital sooner. However, when administered it can also slow the breathing of patients and cause others to have upper airway obstruction (such as snoring) which can impede proper spontaneous breathing. Ketamine is an agent that is capable of providing both pain control and sedation while having either minimal effect on breathing or promoting spontaneous breathing. Combining Ketamine with Propofol has the potential to reduce the total amount of Propofol used resulting in a procedure being performed under the same level of sedation but without the downside of reduced spontaneous breathing. Patients who are obese (defined as body mass index greater than 35) tend to be even more susceptible to this effect of Propofol. The researchers are investigating whether the addition of Ketamine will indeed allow for this continued comfortable level of sedation while promoting continued spontaneous breathing in obese patients undergoing upper gastrointestinal endoscopies.

Upon patient arrival to endoscopy suite heart rate (HR), pre-procedure baseline blood pressure (BP), and pre-procedure oxygen saturation (SPO2) via pulse oximeter are recorded in endoscopy holding area, patient alertness and orientation assessed (respond to name, know the state, know the hospital, know the year, know the season).

Once the subject enters the endoscopy suite monitors are placed to record starting BP, HR, SPO2 recorded, nasal cannula with end tidal carbon dioxide (CO2) monitor attached, and 5-lead ECG.

Following time out patient given 100mg Lidocaine IV bolus, 1-minute delay, then study-provided syringe administered. Once patient assessed to produce an RSS score >5 (Asleep with sluggish response to glabellar tap or NO response) endoscopy proceeds.

Recorder (blinded) notes if initially provided syringe alone was enough to produce an RSS >5, notes subject's response to endoscopy insertion (presence or absence of gagging), notes amount of additional propofol required to maintain adequate conditions to continue endoscopy, records non-invasive blood pressure (NIBP) at 3-minute intervals, notes for level of airway obstruction (obstruction with continued air movement, obstruction requiring chin lift or jaw thrust for relief, obstruction requiring progression to assisted ventilation or intubation), notes for desaturation events (SPO2 <90% with a coherent waveform).

At the end of the procedure the total anesthesia time is recorded, total procedure start-to-finish time recorded, total dose of propofol recorded, and any incidence of patient agitation noted.

Once in recovery the recovery room admission HR, SPO2, NIBP recorded followed by admission +15 minutes HR, SPO2, and NIBP, any incidence of desaturation (<90% SPO2 with waveform) recorded, incidence of airway obstruction (with air movement, requiring airway maneuver, requiring intervention) recorded, time until patient is alert and oriented recorded (response to name, able to state what state they are in, able to state what hospital they are in, able to state the year, able to state the season), time-until-recovered recorded (Modified Aldrete Score > 9), incidence of nausea prior to recovery recorded, incidence of vomiting prior to recovery recorded, incidence of agitation or delirium prior to recovery recorded.

Inclusion Criteria:

• BMI > 30
• Undergoing an upper gastrointestinal endoscopy

Exclusion Criteria:

• History of schizophrenia/schizoaffective disorder
• History of bipolar disorder
• History of dementia
• Non-English Speaking
• History of Glaucoma
• Craniofacial Abnormalities
• Epilepsy
• Allergy to Propofol
• Allergy to Ketamine
• Current known intracranial mass/lesion

6 months