BMJ  2006;333:653-654 (23 September), doi:10.1136/bmj.333.7569.653-b

Letter

Acute renal failure from contrast medium

... and remember simple and cheap measures

EDITOR—Mathew et al describe some of the risk factors and consequences of contrast induced nephropathy, a condition increasingly encountered after elective and emergency cardiac angiography and angioplasty.¹ The role of N-acetylcysteine in preventing this common condition is often underemphasised. Many good prospective randomised controlled trials support its use, as do most meta-analyses, but the strength of overall conclusions is often hindered by the heterogeneity of the study protocols of the included trials. A dose dependent relation with both oral and intravenous administration has clearly shown a reduction of contrast induced nephropathy in patients undergoing cardiac angiography.^{2 3}

Pre-hydration is simple, cheap, carries minimal risk, and should be routinely used despite the lack of a large prospective randomised controlled trial of hydration versus no hydration. Correction of subclinical dehydration may be the principal benefit. However, the route and type of fluid prescribed seem to be important in preventing contrast induced nephropathy. Intravenous isotonic fluid (0.9% saline) is more effective than half isotonic fluid (0.45% saline),⁴ and intravenous administration is more effective than oral.⁵ Most benefit is seen in high risk groups.

Heart Hospital, London W1G 8PH amit.patel{at}doctors.org.uk

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Competing interests: None declared.

References

1. Mathew R, Haque K, Woothipoom W. Acute renal failure induced by contrast medium: steps towards prevention. BMJ 2006;333: 539-40. (9 September.)[Free Full Text]
2. Briguori C, Colombo A, Violante A, Balestrieri P, Manganelli F, Paolo Elia P, et al. Standard vs double dose of N-acetylcysteine to prevent contrast agent associated nephrotoxicity. Eur Heart J 2004;25: 206-11[Abstract/Free Full Text]
3. Marenzi G, Assanelli E, Marana I, Lauri G, Campodonico J, Grazi M, et al. N-acetylcysteine and contrast-induced nephropathy in primary angioplasty. N Engl J Med 2006:354: 2773-82[Abstract/Free Full Text]
4. Mueller C, Buerkle G, Buettner HJ, Petersen J, Perruchoud AP, Eriksson U, et al. Prevention of contrast media-associated nephropathy: randomized comparison of 2 hydration regimens in 1620 patients undergoing coronary angioplasty. Arch Intern Med 2002;162: 329-36[Abstract/Free Full Text]
5. Trivedi HS, Moore H, Nasr S, Aggarwal K, Agrawal A, Goel P, et al. A randomized prospective trial to assess the role of saline hydration on the development of contrast nephrotoxicity. Nephron Clin Pract 2003;93: C29-34[CrossRef][ISI][Medline]

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Acute renal failure induced by contrast medium: steps towards prevention

R Mathew, K Haque, and W Woothipoom
BMJ 2006 333: 539-540. [Extract] [Full Text] [PDF]