Pharmacokinetic Response to BPI in Burns

Inclusion Criteria: * Ages 13 years to 60 years old * Sustained partial-thickness or full-thickness burn greater than 20% and less than 41% TBSA * Parental consent (if subject is less than 18 years old) or individual (if subject is equal to or older than 18) signed, informed consent. * Able to start BPI in infusion within 8 hours of burn injury. Exclusion Criteria: * Age \> 61. * Inhalational injury requiring mechanical ventilation. * Partial and full thickness burns totaling \> 41% total body surface area * Cardiac dysfunction, defined as the presence of any of the following: 1. New York Heart Class 3 or 4 heart failure. 2. Unstable angina or acute myocardial infarction. 3. Left ventricular ejection fraction known to be \< 35%. * Electrical or lightening induced burn injury or any injury that required cardio-pulmonary resuscitation. * Concomitant non-burn trauma with an ISS \> 9. * Non-survivable injury secondary to burn size - patients made DNR or comfort care due to burn size. * Patients with known causes of immunosuppression: 1. Known history of HIV/AIDS 2. Chronic steroid use for underlying medical conditions (equivalent to 15 mg prednisone/day). 3. Active oncolytic therapy for known malignancy * Known or suspected pregnancy * Known allergy to rBPI21