Sub-dissociative Dose Ketamine Dosing Study

Study investigators will enroll participants who present to the Emergency Department (ED) with moderate to severe acute pain, and require intravenous pain medication. Participants will be double-blinded and randomized to one of the two treatment groups.

Investigators aim to determine if ketamine 0.15 mg/kg IVPB is non-inferior to ketamine 0.3 mg/kg IVBP for the treatment of acute moderate to severe pain in the Emergency Department (ED). Study investigators hypothesize that in adults presenting to the ED with moderate to severe acute pain, SDK administered at 0.15 mg/kg will provide similar pain relief to SDK at 0.3 mg/kg, with reduced adverse effects.

Inclusion criteria

• Adults ages 18-59
• Weight 45 - 115 kg
• Acute abdominal, flank, back, musculoskeletal pain, or a headache
• Onset of pain within 7 days
• Pain score of 5 or more
• Requiring intravenous analgesia
• Hasn't been enrolled in this study previously

Exclusion criteria

• Pregnancy
• Breast-feeding
• Altered mental status rendering the patient unable to consent to the study
• Allergy to ketamine
• Unstable vital signs (systolic blood pressure <90 or >180 mm Hg, pulse rate <50 or >150 beats/minute, and respiration rate <10 or >30 breaths/minute)
• History of acute head or eye injury, seizure, intracranial hypertension
• Chronic pain
• Renal or hepatic insufficiency
• Known alcohol or drug use disorder
• Currently under influence of alcohol/opiates
• Acute psychiatric illness