Working towards prevention of acute kidney injury in patients undergoing cardiac surgery

Michael Zhu

Congratulations to School of Clinical Sciences at Monash Health (SCS) student Michael Zhu, the recipient of the Young Achiever's Award at the Annual Scientific Meeting of the Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) in Cairns last week for his research into acute kidney injury. 

A Surgery BMedSc(Hons) student in 2016, Michael’s research study may help prevent acute kidney injury in patients undergoing cardiac surgery.

“Acute kidney injury (AKI) after cardiac surgery is a common, yet difficult problem to tackle,” said Head of Department of Surgery Professor Julian Smith, one of Michael’s supervisors.

“Michael’s research may allow clinicians to detect the real-time risk of AKI intraoperatively, offering an opportunity to predict AKI up to 1-2 days earlier than current methods of diagnosis.”

The prospective study undertaken at Monash Medical Centre and Monash University used a clinically translatable and minimally invasive technique, involving a fibre optic oximetry probe deployed in the urinary catheter, to evaluate the relationship between urinary oxygen tension (PO₂) and the development of AKI after cardiac surgery requiring cardiopulmonary bypass (CPB).

“The data indicate that patients who later developed AKI experienced significantly longer and more severe periods of urinary hypoxia intraoperatively; with a median of 14 min per hour of surgery in the AKI group, compared to just 30 seconds per hour of surgery in the non-AKI group,” said Michael.

The promising study has shown that real-time monitoring of risk of AKI during cardiac surgery is feasible and may be prognostically useful. This may in-turn offer clinicians the opportunity to intervene in the operating theatre to minimise the risk of AKI.

Michael said the next step will be to investigate, in a large animal model, whether intraoperative interventions (e.g. during CPB) can result in changes in renal and urinary oxygenation.

“This may translate to strategies to reduce the risk of AKI in patients having open-heart surgery,” added Michael.

Michael thanks his dedicated supervisors, Professor Smith, Associate Professor Roger Evans and Associate Professor Andrew Cochrane for their tremendous support throughout his Honours year.