This study will prospectively compare the mean Numerical Rating Scale (NRS) pain score
reduction amongst three recommended dosing strategies of intravenous ketamine (0.1 mg/kg, 0.2
mg/kg, and 0.3mg/kg) for acute pain in the emergency department (ED).This study will also
examine the frequency of adverse events secondary to ketamine including fatigue, dizziness,
nausea, headache, feeling of unreality, changes in hearing or vision, mood changes,
generalized discomfort, and hallucinations, changes in vital signs. Subgroups for exploratory
analysis based on the need for rescue analgesia within two hours of ketamine administration,
adequate pain relief, previous opioid tolerance, and age (adults < 65 years old and > 65
years old).