Ketamine Patient-Controlled Analgesia for Acute Pain

Inclusion Criteria: * Age greater than or equal to 18 years * Total Injury Severity Score greater than 9 * Functioning intravenous catheter present per standard of care * Patient planned to receive PCA for acute pain per standard of care * Patient ability to effectively use a PCA device as assessed by the primary attending trauma service * Negative pregnancy test for women of childbearing age Exclusion Criteria: * Body mass index greater than 35 * History of active psychiatric disease * Acute or chronic liver or renal failure * History of heart failure or coronary artery disease * Patients with documented chronic pain syndrome who use opioids as maintenance medication in outpatient therapy * Patients who abuse alcohol and are at high risk for alcohol withdrawal * Intubated patients * Glasgow Coma Scale score less than 13, or motor subscore less than 6 * Documented allergy to ketamine, hydromorphone, or lorazepam * Pregnancy * Incarceration