Low Dose Ketamine Infusion for Analgesia in the Emergency Department to Reduce Side Effects

Inclusion criteria:

* Patients aged 18 or older
* Primary complaint of acute moderate to severe pain on VAS/ numeric pain scale (a score of ≥5cm which corresponds to 50mm).
* Pain described as abdominal, flank, back, musculoskeletal, or traumatic chest pain
* Must be alert and oriented times three
* Able to provide consent

Exclusion criteria:

* Pregnant
* Breastfeeding
* Altered mental status
* Known or reported allergy, hypersensitivity or intolerance to ketamine
* Unstable vital signs (systolic blood pressure \<80 or \>180mmHg, heart rate \<50 or \>150 beats per minute, and respiratory rate \<10 or \>30 breaths per minute)
* History of unstable heart disease, such as arrhythmias, congestive heart failure, or coronary heart disease.
* History of untreated or uncontrolled thyroid disease
* Acute head or eye injury
* Active or current use of alcohol or drugs
* Known intracranial hypertension
* Hepatic or renal insufficiency
* Current active manic phase of bipolar disorder
* Active delusions, hallucinations, or schizophrenia
* Patients who have recent fentanyl use within 60 minutes or other analgesic use (opiates) within 4 hours of study enrollment (signing of consent)
* Patients who have enrolled in the study during a previous ED encounter
* Chronic use of opiates (i.e.: fentanyl patch, SR opiates)