MEDIA RELEASE
EMBARGO: 21.30PM, MONDAY 2nd NOVEMBER
Kidney injury due to contrast used in X-rays: Research reveals uncertainty around
preventative treatment
People undergoing X-rays often require an intravenous contrast injection to improve the quality of the
information obtained. Some of these patients will develop acute kidney injury as a result, and may require
dialysis or hospitalisation. New research released today has revealed that the effectiveness of a common
treatment used in high-risk patients has been over-estimated and remains uncertain.
Sodium bicarbonate treatment is widely used by clinicians across the world for the prevention of contrast-
induced nephropathy (CIN), which accounts for 10% of all cases of acute kidney injury requiring
hospitalisation. Researchers from The George Institute suggest that earlier reports have overestimated any
benefits and that improved and larger trials are required.
Lead author, Dr Sophia Zoungas, The George Institute said, “Previous research has suggested that this
treatment is beneficial. However, our new comprehensive systematic review suggests that the benefits of
sodium bicarbonate remain to be demonstrated and have been overestimated in previous reports. As
such, we believe the routine use of sodium bicarbonate is premature. This is particularly important as this is
a treatment that makes x-rays much more complicated and expensive than would otherwise be the case,
not to mention using scarce hospital resources.”
“Clinicians need to examine the quality of systematic reviews in order to determine whether the conclusions
made are indeed accurate. Our review demonstrates that the comprehensive and methodical approach
undertaken considerably altered the conclusions regarding the effects of this treatment,” added Associate
Professor Vlado Perkovic, The George Institute.
Researchers reviewed 9 published and 14 unpublished trials of sodium bicarbonate that included
information on 3563 patients and 396 CIN events aiming to provide a reliable estimate of the nature and
strength of any treatment effect. In the comprehensive meta-analysis, the research did not find clear
evidence of overall benefit associated with the use of sodium bicarbonate to prevent CIN. The study also
found that the inconsistency between previous findings highlighted the need for a high quality large trial that
will clearly define the effects of intravenous sodium bicarbonate.
CIN, a form of acute renal failure, is a leading cause of hospital-acute kidney injury caused by the
administration of contrast media for X-rays. People receiving contrast to improve the quality of various
types of X-rays will develop reduced kidney function in up to 10% of cases. While many of these people
recover spontaneously, in its most severe form, CIN is associated with clinically significant morbidity and
mortality, including prolonged hospitalisation, requirement for dialysis, and an increased risk of death.
The new systematic review included more studies than previous research, and explored the results in more
detail than ever before. Upon reviewing the research, researchers found that small early studies of lesser
quality tended to suggest larger benefits, while more recent, larger and higher quality studies tended to find
little or no benefit with the treatment.
###ENDS###
For further information, please contact:
Angela Byrnes
The George Institute for International Health
Mobile: +61410 411 983
Email: abyrnes@george.org.au
The George Institute is a world renowned health and medical research institute, focused on the
prevention and management of chronic disease and injury. The George is affiliated with the University of
Sydney and conducts high-impact research across a broad health landscape and is a respected voice
among global policy makers. The George has conducted major global applied research projects and
innovative community-based programs from bases in Australia, China and India. In 2009, the Institute
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