Morphine or Ketamine for Analgesia

Pain is common in children presenting to the emergency department but is frequently undertreated, leading to both short- and long-term consequences. Morphine is the standard treatment for children with moderate to severe acute pain, but its use is associated with serious side effects and caregiver and clinician concerns related to opioid administration. The investigators aim to determine if sub-dissociative ketamine is non-inferior to morphine for treating acute pain and a preferable alternative for treating acute pain in children because of its more favorable side effect profile and potential long-term benefits related to pain-related function, analgesic use/misuse, and mental and behavioral health outcomes.

Aim 1: To determine if IV sub-dissociative ketamine is non-inferior to IV morphine for decreasing pain intensity in children presenting to an ED with acute pain. The investigators hypothesize that IV sub-dissociative ketamine is non-inferior to IV morphine for decreasing pain intensity in children with acute abdominal pain or an extremity fracture.

Aim 2: To compare the rate of acute (<2 hours) adverse events, including cardiopulmonary adverse events, associated with IV sub-dissociative ketamine and IV morphine. The investigators hypothesize that there is a smaller proportion of cardiopulmonary adverse events associated with IV sub-dissociative ketamine compared to IV morphine.

Aim 3: To determine the relationship between ketamine and long-term sequelae of acute pain. The investigators hypothesize that children who receive ketamine will have better levels of pain-related function during the first week following ED presentation and will have greater odds of experiencing more favorable post-traumatic stress, anxiety and depression outcomes 1-6 months after ED presentation compared to children who received IV morphine.