Sepsis is the most common cause of childhood death worldwide. Millions of children survive, but are left with impaired health. Sepsis-related Acute Kidney Injury (sAKI) is increasingly recognized as a significant factor associated with long-term mortality among different patient populations. Renal dysfunction and subsequent chronic kidney disease is implicated in the development of hypertension and cardiovascular disease. The investigators overall hypothesis is that, in the pediatric population, sepsis-related AKI will have unrecognized, long-term consequences with regard to kidney function, endothelial function, blood pressure control, and overall health.

This will be a two-arm cross-sectional control-cohort outpatient evaluation. Subjects with sAKI and a random selection of non-sAKI subjects who agree to participate in another study of quality of life survey will be asked to participate in the outpatient study. Subjects will be asked to come in to the Clinical Research Center for 24-hour monitoring and participate in the outpatient study where urinary and serum studies to measure glomerular filtration rate, renal plasma flow followed by blood pressure monitoring, peripheral arterial and applanation tonometry.

Inclusion Criteria:

For all patients:

• Age 18-24 at time of participation in the study

For non-AKI sepsis patients:

• Hospitalization with a diagnosis of sepsis from 1998-2014
• Failure to meet pEDRIFLE criteria for AKI during incident sepsis admission
• Participation in cognitive survey study with completion of the PedsQL survey

For sAKI patients:

• Hospitalization with a diagnosis of sepsis from 1998-2014
• Severe AKI as defined by the pEDRIFLE criteria during incident sepsis admission
• Participation in cognitive survey study with completion of the PedsQL survey

Exclusion Criteria:

For all patients:

• Known pre-existing CKD as defined by history of kidney transplant or long-term dialysis
• Age greater than 18 years at the time of incident sepsis admission
• AKI from primary kidney disease including acute glomerulonephritis and obstructive uropathy
• Pregnancy at the time of enrollment
• Known or suspected allergy to gadolinium based contrast
• Known or suspected allergy to iodine or shellfish will be excluded from RPF measurement with iodohippurate
• Heart failure or condition whereby the administration of 0.9% normal saline would be contraindicated

Intent to contact and enroll subjects with severe sepsis related AKI subjects without sepsis related AKI and a sample of age and sex-matched healthy controls.