Inflammation and metabolism are closely interlinked and both undergo significant dysregulation following surgery for congenital heart disease, contributing to organ failure and morbidity.

Surgery itself can cause complications, affecting how the body responds to injury and infection with inflammation, regulation of metabolism, growth and development, tissue function, sleep, and mood, among other things and metabolism itself.

A team of scientists led by those at the University of Cambridge (UK) followed 28 children, with a median age of 6.6 months, who were undergoing surgery for congenital heart disease. The children were part of a wider trial looking at management of blood sugar in 1,300 critically ill children and hence 15 of the children had their blood sugar levels tightly controlled using insulin, whilst the remaining 13 underwent the standard blood sugar control treatment. The team took blood samples from before surgery through to 48 hours afterwards, and analyzed the various molecules present using nuclear magnetic resonance (NMR).

Cytokine concentrations in plasma samples were determined in duplicate using MSD MULTI-SPOT immunoassay kits for interleukins (IL) 10, 6, 8, and IL-1 receptor antagonist (IL-1ra) (Mesoscale Discovery; Gaithersburg, MD, USA). A Bruker AVANCE III spectrometer (Bruker Biospin; Billerica, MA, USA) with a broadband inverse 600 MHz 5 mm Z gradient probe with automatic tuning and matching was used for all the 1H NMR spectroscopy studies.

The investigators found a link between certain metabolites found in the blood and a child's clinical outcome. The greater the presence of ketone bodies, chemicals produced when the body does not have enough insulin in the blood and must break down fat instead of the sugar for energy, correlated with better outcomes. However, the presence of other metabolites such as citrate, lactate and alanine correlated with poorer outcomes. They found no difference in clinical outcome between those patients whose blood sugar levels were tightly controlled and those who received the standard blood sugar control treatment.

Nazima Pathan, FRCPCH, PhD, a clinical senior lecturer who led the study said, “We've shown that the presence of certain molecules in a child's blood following heart surgery can help predict how well a child will recover in the crucial hours and days immediately following surgery. This opens up the possibility of us being able to identify those children at greatest risk following surgery and target them with the appropriate critical care management.” The study was published on April 3, 2015, in the journal Critical Care Medicine.

Related Links:
University of Cambridge
Mesoscale Discovery 
Bruker Biospin