Acute Kidney Injury Following Paediatric Cardiac Surgery
Condition: Acute Kidney Injury
MeSH terms: Acute Kidney Injury; Wounds and Injuries
Study type: Observational

Summary: 
      Acute kidney injury (AKI) complicates over 50% of cardiac surgical procedures in children
      where it increases morbidity and the use of healthcare resources. The pathogenesis of AKI is
      poorly understood, current diagnostic tests lack specificity and sensitivity, and there is no
      effective treatment. Improving outcomes in patients at risk of AKI has recently been defined
      as a National Health Service priority. The investigators are currently undertaking a program
      of work that is evaluating the role of plasma-derived microvesicles (MV) and MV associated
      microRNAs (miRNA) as diagnostic biomarkers or therapeutic targets in cardiac surgery patients
      at risk of developing AKI. Preliminary results indicate that these biomarkers may have
      clinical utility in adults. An important consideration is whether these biomarkers also have
      utility in children undergoing cardiac surgery. Measurement of MV at serial time points in
      children presents ethical challenges related to conducting clinical research in critically
      ill subjects. It also presents technical challenges related to the very small volumes of
      blood that may be sampled safely from babies and infants undergoing surgery. The aim of the
      study is to provide estimates of the perioperative variance of MV concentrations in 24
      children undergoing cardiac surgery, as well as the frequency of AKI and other adverse
      events, protocol adherence and recruitment rates. This will assist with the design of a
      subsequent prospective observational study that will consider the role of MV/miRNA in
      children undergoing cardiac surgery.
    

Detailed description: 
      This is a prospective, single-centre observational feasibility study that will measure
      changes in MV signalling and their relationship to inflammatory responses after cardiac
      surgery in children.

      The investigators primary hypothesis is that inflammatory renal injury following paediatric
      cardiac surgery is regulated by circulating MV and more specifically MV associated miRNA.

      The investigators secondary hypotheses are:

        1. MV derived signals will differ in cyanotic patients, a patient group at significantly
           increased risk for AKI.

        2. MV subsets and/or MV derived miRNA may act as novel diagnostic biomarkers for AKI.

      To assist with the design of a prospective observational study that will test these
      hypotheses the investigators propose to undertake a feasibility study in 24 children. The
      objectives of this feasibility study are:

      A.To establish the numbers of patients that are eligible for enrolment in the study, the
      number recruited to the study, and their clinical and demographic characteristics.

      B.To determine the proportion of consented patients who develop AKI following cardiac
      surgery.

      C.To measure perioperative changes in MV subgroups and MV associated miRNA, as well as
      platelet and monocyte activation, and the variance of these measures.

      D.To establish protocol adherence, with respect to the adequacy and timing of the blood
      samples that are taken and the calculation of creatinine clearance perioperatively.
    

Intervention name(s): cardiac surgery
Intervention type(s): Procedure
Intervention description(s): cardiac surgery with extracorporeal circulation for congenital heart disease
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Children undergoing cardiac surgery in a tertiary academic cardiac surgery unit
      
Biospecimen description: 
      -  serum

        -  EDTA plasma

        -  citrated blood

        -  hirudin blood

        -  urine
    
Keywords: Acute Kidney Injury; Microvesicles; microRNA; Paediatric cardiac surgery