This study has been withdraw from the IRB. The PI has transferred to another university. The IND was transferred.

The purpose of this study is to determine the possible effects of an anesthetic agent called Ketamine on the injured brain in children.

The researchers think that it will effect the outcomes of children with these injuries.

Inclusion Criteria:

• are 1 month to 16 years of age; AND
• are admitted to the PICU following severe TBI (any GCS 3-8 inclusive) within 8 hours after the injury; AND
• are intubated and ventilated for the management of TBI; AND
• are anticipated to have an indwelling arterial or venous catheter for blood sampling during the first three days of study enrollment; AND
• have an intra-cranial pressure (ICP) monitoring device for management of TBI.

Exclusion Criteria:

• are less than 4 kilograms in weight upon admission
• are less than 1 month of age;
• are greater than 16 years of age;
• have a clinical diagnosis of non-accidental TBI;
• have suffered immersion injury or prolonged hypoxic injury (lasting greater than 10 minutes);
• have a known allergy to ketamine;
• have a planned removal of endotracheal tube or the removal of central venous catheter AND arterial catheter within 72 hours of study enrollment;
• have a current history of neuromuscular disease;
• have a current history of hepatic failure;
• have a current history of glaucoma
• require chronic treatment with anti-epileptic drugs (AEDs) or devices;
• more than 8 hours have elapsed from the time of injury to PICU admission;
• have documentation of a positive pregnancy test at the time of enrollment;
• if there is a lack of commitment to aggressive intensive care therapies (the subject is either on a DNR status due to pre-existing medical condition, or the family decides to withdraw support prior to participation in the study due to other multiple severe injuries and organ failures resulting from the trauma).