Low Dose Ketamine (LDK) Versus Morphine for Acute Pain Control in the Emergency Department

Inclusion Criteria:

* Patients age 18-59 who present to the Brooke Army Medical Center Emergency Department with acute (less than 10 days) abdominal pain, flank/lumbar back pain and or/pain to the extremities, and of sufficient severity in the judgement of the ED treating physician or PA to warrant use of intravenous opioids

Exclusion Criteria:

* Poor vital sign stability hypoxia: Sats\<95% hypotension: SBP\<90 hypertension: SBP\>180 heart rate: \<50 or \>120 respiratory rate: \<10 or \>30
* Altered mental status or intoxication
* Patient is unwilling to participate or provide informed consent
* History of chronic pain or pain syndrome with concurrent opioid medication use
* fibromyalgia
* Patient has received opioids and/or tramadol in the past 4 hours
* Prescription pain medication use (to exclude muscle relaxants, acetaminophen or NSAIDs including toradol) in the past 4 hours
* Allergy to morphine or ketamine
* Sole provider status
* Adverse reaction to morphine or ketamine in the past
* Patients, who in the opinion of the triage nurse, require immediate analgesic relief
* Patient is female of child-bearing age and unable to provide urine or serum for HCG analysis in triage
* Pregnancy or breast feeding
* Presence of oxygen dependent pulmonary disease, liver cirrhosis or Renal disease requiring dialysis. (as assessed by electronic chart review)
* Presence of Ischemic heart disease, heart failure or unstable dysrhythmias (as assessed by electronic chart review)
* Presence of intracranial mass or vascular lesion.
* Presence of psychosis or hallucinations
* Weight greater than 115kg or less than 45 kg
* History of acute ocular/head trauma
* History of increased intracranial pressure/hypertensive hydrocephalus
* Non-English speaking patients