Perioperative Ketamine for Pain With Gastric Bypass

Study Overview
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Brief Summary
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Opioid medications such as morphine, hydrocodone and oxycodone are standard for treating pain after surgery, however there are disadvantages. Because of the way opioids work, gastric bypass patients may have an increased risk of having sedation or problems with breathing. In patients with sleep apnea, opioids may increase the risk of severe apnea. Ketamine is an alternative pain medicine that can be used to treat pain after surgery and may have fewer effects on breathing. Using ketamine as part of the regimen may be a better choice for laparoscopic gastric bypass patients. This study is being done to find out if intraoperative ketamine infusion combined with continuation for twenty-four hours post-surgery provides superior pain control and decreases post-operative opioid use versus standard non-ketamine therapy.

Official Title
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Low-dose Ketamine Infusions for Perioperative Pain Management in Patients Undergoing Laparoscopic Gastric Bypass

Conditions
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Laparoscopic Gastric Bypass Surgery, Ketamine

Intervention / Treatment
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* Drug: Ketamine
* Drug: Standard therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing laparoscopic gastric bypass at Mayo Clinic in Arizona BMI is ≥ 35 kg/m2 Consent is able to be obtained as per Mayo Clinic policy Exclusion Criteria: Intolerance to ketamine History of schizophrenia, schizoaffective disorder, or other psychiatric diagnosis with psychotic features Presence of unstable cardiovascular disease (presence of acute coronary syndrome, unstable angina, hypertension emergency, acute transient ischemic attack (TIA) or stroke) Presence of acute elevation of intracranial or intraocular pressure Presence of seizure disorder History of substance abuse or addiction Creatinine greater than 1.5 mg/dL End-stage liver disease Pregnancy Patients with chronic pain and/or chronic opioid therapy will not be excluded to more closely replicate the study patient population of interest. However, patients taking greater than 50 morphine equivalents (ME) per day for greater than 1 month prior to surgery will be excluded.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 69 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ketamine Therapy<br>Ketamine 0.3 mg/kg (IBW) bolus with induction. Ketamine infusion 0.2 mg/kg/hr. (IBW) initiated after induction and terminated after 24 hours. Ketamine infusion will not be titrated. Remaining care will be identical to standard therapy group. | Drug: Ketamine<br>* Ketamine 0.3 mg/kg (IBW) bolus with induction. Ketamine infusion 0.2mg/kg/hr. (IBW) initiated after induction and terminated after 24 hours. Ketamine infusion not titrated.<br>|
| Active Comparator: Standard Therapy<br>Calculation ideal body weight (IBW) Pre-op dexamethasone Pre-op midazolam at discretion of anesthesiologist Anesthesia Induction - Propofol and fentanyl, anesthesiologist discretion. Neuromuscular block with succinylcholine and/or rocuronium at discretion of anesthesiologist. Orotracheal intubation. Anesthesia Maintenance - Sevoflurane/rocuronium. Addl. doses of fentanyl, discretion of anesthesiologist. Emergence from anesthesia - Acetaminophen, Ketorolac and Ondansetron unless contraindicated. Sugammadex depending on twitch response per drug manufacturer recommended protocol. Post-Op Analgesia - Hydromorphone, acetaminophen and ketorolac Other post-op care as per usual surgical routine | Drug: Standard therapy<br>* Pre-op dexamethasone 4mg IV and midazolam 1-2mg IV Anesthesia Induction - Propofol 2-3mg/kg IV, Fentanyl 1mcg/kg IV, neuromuscular block w/succinylcholine and/or rocuronium, orotracheal intubation Anesthesia maintenance - Sevoflurane/rocuronium, fentanyl 0.5-1mcg/kg Anesthesia emergence - Acetaminophen 1g, ketorolac 30 mg IV, ondansetron 4mg IV, sugammadex 2mg/kg or 4 mg/kg dose depending on twitch Post-op anesthesia - Hydromorphone patient-controlled analgesia (PCA) 0.2 mg/8 min, acetaminophen 1 g IV Q8 around the clock (ATC) x 3 addl. doses, ketorolac 15 mg IV Q6 ATC x 3 addl. doses. Other standard surgical post-op care<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total Cumulative Perioperative Opioid Dose | Measured in oral morphine equivalents | approximately 48 hours after induction of anesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average Pain Score 0-12 Hours | Patient reported pain scores at 0-12 hours post operatively. Measured by a 100 mm long Visual Analog Scale (VAS). The VAS does not have any pre-set marks between the extremes of 0 for no pain and 100 mm for extreme pain. The investigator measures the mark made by the participant in mm and records this for the value of pain. A higher score indicates great pain intensity. | approximately 0-12 hours post operatively | 
| Average Pain Score 12-24 Hours | Patient reported pain scores at 12-24 hours post operatively. Measured by a 100 mm long Visual Analog Scale (VAS). The VAS does not have any pre-set marks between the extremes of 0 for no pain and 100 mm for extreme pain. The investigator measures the mark made by the participant in mm and records this for the value of pain. A higher score indicates great pain intensity. | approximately 12-24 hours post operatively | 
| Average Pain Score 24-48 Hours | Patient reported pain scores at 24-48 hours post operatively. Measured by a 100 mm long Visual Analog Scale (VAS). The VAS does not have any pre-set marks between the extremes of 0 for no pain and 100 mm for extreme pain. The investigator measures the mark made by the participant in mm and records this for the value of pain. A higher score indicates great pain intensity. | approximately 24-48 hours post operatively | 
| Post-Operative Nausea | Number of subject to experience post-operative nausea | 12 hours, 24 hours, and 48 hours | 
| Length of Stay in Hospital | Length of hospital stay measured in hours | Arrival at hospital until discharge from hospital, approximately 2 days | 
| Patient Satisfaction With Pain Control at Time of Hospital Discharge | Self-reported questionnaire at the time of discharge from the hospital rating satisfaction of pain treatment while in the hospital using a scale of 0= extremely dissatisfied, 10 = extremely satisfied. | approximately 1-2 days post-operatively | 
| Patient Satisfaction With Pain Control at Postoperative Visit | Self-reported questionnaire at the time of first post-operative visit with the surgeon, rating the worst amount of pain since being discharged from the hospital using a scale of 0= no pain, 10 = worst pain possible. | approximately 30 days post-operatively |