Single-dose Ketamine for the Reduction of Pain and Depression in the Emergency Department

The investigators will enroll 120 medically stable adult patients who present to two Emergency Departments with a chief complaint of acute pain.

The investigators will randomly assign subjects using a blocked randomization schedule to either: 1) a single dose of IV ketamine (0.3 mg.kg) + midazolam, or 2) placebo + midazolam. ED providers and patients will be blind to treatment allocation.

All participants will complete measures of pain and mood scores every 30 minutes, and the investigators will record any analgesics administered in the ED until discharge. At 7-days and 14-days post- discharge, the investigators will measure summary reports of pain severity, mood, and analgesic medication used.

• Ketamine (Drug): Ketamine is a medication approved by the US Food and Drug Administration (FDA) for anesthesia, sedation, and post-surgical pain treatment. It is not approved for emergency patients complaining of pain but is often used "off-label." Ketamine may be useful for acute pain management and in treatment of depressed mood. The purpose of this study is to determine whether a single low dose of ketamine can relieve pain and reduce negative mood for 2 weeks after emergency department (ED) treatment.
• Midazolam (Drug): In this study, all patients will also receive midazolam. Midazolam is a sedative that typically makes people feel relaxed and is intended to increase comfort with ketamine and reduce anxiety.
• Placebo (Drug): In this study, patients in the active comparator group will receive midazolam first, then placebo. A placebo is an inactive solution that looks like the study drug, but contains no active ingredients.

Primary outcomes

• Pain Intensity in the ED [Pain intensity rating in the ED at 1-hour post-study drug administration]: Pain Numeric Rating Scale (PNRS)- this item is anchored to pain intensity "right now" on a scale from 0(no pain)-10 (worst pain imaginable)

Secondary outcomes

• Pain Intensity at Follow-Up [Pain Intensity at 1-week post-ED Discharge]: Pain Numeric Rating Scale (PNRS): this item is anchored to pain intensity within the past 7-days on a scale from 0 (no pain) to 10 (worst pain imaginable)

Sex: All, ages: 18 Years to 65 Years

Inclusion Criteria:

1. Adults between the ages of 18-65
2. A chief complaint of painful condition (pain score ≥ 5 on the numeric rating scale \[NRS\] from 0-10 with anchors of 0 = "no pain" and 10 = "worst pain imaginable")
3. Expected to be in the ED for at least 2 hours

Exclusion Criteria:

1. Non-English speaking
2. Not medically suitable for ketamine per treating MD (e.g. medical condition where ketamine is contraindicated); ketamine or midazolam may be unsafe (e.g., known sensitivity, glaucoma, or other concerns)
3. Not alert and oriented
4. Active psychosis, self-injury, suicidal/homicidal intentions on initial evaluation by treating team
5. Seeking treatment due to a mental health or substance use disorder
6. History of chronic opioid use
7. Prescribed opioid use within the past 24 hours
8. Any use of recreational narcotics throughout lifetime
9. Sensitivity or allergy or intolerance to ketamine, opioids, and/or benzodiazepines
10. Weight > 170kg (375 lbs)
11. Current neurological disease (e.g., multiple sclerosis, stroke, brain tumor, seizure disorder, etc.)
12. Pregnancy
13. Prisoner

• Maria L Pacella, PhD, Principal investigator, University of Pittsburgh