Contrast-induced nephropathy is a form of kidney damage in which there has been recent exposure to medical imaging contrast material without another clear cause for the acute kidney injury. CIN is classically defined as a serum creatinine increase of at least 25% and/or an absolute increase in serum creatinine of 0.5 mg/dL after using iodine contrast agent without another clear cause for acute kidney injury, but other definitions have also been used.
Despite extensive speculation, the actual occurrence of contrast-induced nephropathy has not been demonstrated in the literature. The mechanism of contrast-induced nephropathy is not entirely understood, but is thought to include direct damage from reactive oxygen species, contrast-induced increase in urine output, increased oxygen consumption, changes in dilation and narrowing of the blood vessels to the kidneys, and changes in urine viscosity.
Analysis of observational studies has shown that radiocontrast use in CT scanning is not causally related to changes in kidney function. Given the increasing doubts about the contribution of radiocontrast to acute kidney injury, the American College of Radiology has proposed the name postcontrast acute kidney injury which does not imply a causal role, with CIN reserved for the rare cases where radiocontrast is likely to be causally related.
There are multiple risk factors of contrast-induced nephropathy, whereof a review in 2016 emphasized chronic kidney disease, diabetes mellitus, high blood pressure, reduced intravascular volume, and/or old age.
Decreased renal functionEdit
- Estimated glomerular filtration rate (eGFR) < 45 ml/min/1.73 m2 of body surface area before intra-arterial administration with first-pass renal exposure (not passing lungs or peripheral circulation before kidneys), or in the intensive care unit
- eGFR < 30 ml/min/1.73 m2 before intravenous administration or intra-arterial administration with second-pass renal exposure
- Known or suspected acute renal failure
To calculate estimated GFR from creatinine, European guidelines use the CKD-EPI formula in adults ≥ 18 years, and the revised Schwartz formula in children. Swedish guidelines recommends no specific formula in children because of lack of evidence, but on the other hand recommends GFR based on cystatin C rather than creatinine in those with abnormal muscle mass or liver failure or cirrhosis.
Roxana Mehran scoreEdit
- Systolic blood pressure <80 mm Hg - 5 points (if systolic BP less than 80 mmHg for at least one hour requiring inotropic support)
- Intra-arterial balloon pump - 5 points
- Congestive heart failure, counting as NYHA class III (marked limitation in activity due to symptoms, even during less-than-ordinary activity) or worse, or history of pulmonary edema - 5 points
- Age >75 y - 4 points
- Hematocrit level <39% for men and <35% for women - 3 points
- Diabetes mellitus- 3 points
- Contrast media volume - 1 point for each 100 mL
- Decreased kidney function:
- Serum creatinine level >1.5 g/dL - 4 points
- 2 for 40–60 mL/min/1.73 m2
- 4 for 20–40 mL/min/1.73 m2
- 6 for < 20 mL/min/1.73 m2
5 or less points
- Risk of CIN - 7.5
- Risk of Dialysis - 0.04%
- Risk of CIN - 14.0
- Risk of Dialysis - 0.12%
- Risk of CIN - 26.1*
- Risk of Dialysis - 1.09%
- Risk of CIN - 57.3
- Risk of Dialysis - 12.8%
European guidelines include the following procedure-related risk factors:
- Large doses of contrast given intra-arterially with first-pass renal exposure
- Use of contrast agents with high osmolality (limited use today)
- Multiple contrast injections within 48-72 h. At least Swedish guidelines also include gadolinium MRI contrast agents in this aspect.
Swedish guidelines list the following additional risk factors:
The main alternatives in people with a risk of contrast-induced nephropathy are:
- Adjustment of the radiocontrast dose
- Treating or mitigating risk factors
- Using no intravenous contrast for the investigation.
- Switching to another modality such as ultrasonography or MRI.
According to European guidelines, the ratio of the contrast dose (in grams of iodine) divided by the absolute estimated glomerular filtration rate (GFR) should be less than 1.1 g/(ml/min) for intra-arterial contrast medium administration with first-pass renal exposure (not passing lungs or peripheral tissue before reaching the kidneys). Swedish guidelines are more restrictive, recommending a ratio of less than 0.5 g/(ml/min) in patients with risk factors and irrespective of route of administration, and even more caution in first-pass renal exposure.
Treating or mitigating risk factorsEdit
Hydration by drinking or intravenous volume expander, either before or after contract administration, decreases the risk of contrast-induced nephropathy. Evidence also supports the use of N-acetylcysteine with intravenous saline among those getting low molecular weight contrast.[dubious ] The use of statins with N-acetylcysteine and intravenous saline is also supported.
- Oral hydration may be as effective as the intravenous route for volume expansion to prevent contrast-induced nephropathy, according to a review in 2013.
- Adenosine antagonists such as the methylxanthines theophylline and aminophylline, may help although studies have conflicting results.
- N-acetylcysteine (NAC) by mouth twice a day, on the day before and of the procedure if creatinine clearance is estimated to be less than 60 mL/min [1.00 mL/s]) may reduce risk.[medical citation needed] Some authors believe the benefit is not overwhelming. A systematic review concluded that NAC is "likely to be beneficial" but did not recommend a specific dose.[needs update]
- Ascorbic acid may be protective against CIN, according to a systematic review of randomized controlled trials.
While there are currently no FDA-approved therapies for contrast-induced nephropathy, two therapies are currently being investigated. CorMedix is currently in the latter part of phase II clinical trials with approved phase III Special Protocol Assessment for CRMD001 (unique formulation Deferiprone) to prevent contrast-induced acute kidney injury and to slow progression of chronic kidney disease. Dosing trials began in June 2010 in the sixty patient trial.
There is also a phase III clinical trial of RenalGuard Therapy to prevent contrast-induced nephropathy. The therapy utilizes the RenalGuard System, which measures a person's urine output and infuses an equal volume of normal saline in real-time. The therapy involves connecting the person to the RenalGuard System, then injecting a low dose of the loop diuretic furosemide to induce high urine output rates.
A number of studies have reported the ability of RenalGuard to protect patients from CIN following catheterization procedures when compared to the standard of care, including: MYTHOS, which found RenalGuard to be superior to overnight hydration; REMEDIAL II, which found RenalGuard to be superior to sodium bicarbonate hydration; Protect-TAVI, which reported a significant reduction in post-procedural acute kidney injury (AKI) following transcatheter aortic valve replacement (TAVR) when using RenalGuard during the procedure, compared to standard therapy; and AKIGUARD, which showed significant improvement in long-term outcomes when using RenalGuard vs. standard therapy. Two meta-analysis of these results (Putzu and Mattathil) found RenalGuard consistently reduced kidney injury, dialysis, adverse events and mortality compared to standard therapy.
Recently, doubts regarding the significance of the phenomenon appeared in the scientific literature. Several studies have shown that Intravenous contrast material administration was not associated with excess risk of acute kidney injury (AKI), dialysis, or death, even among patients with comorbidities reported to predispose them to nephrotoxicity. Moreover, hydration, the most established prevention measure to prevent contrast induced nephropathy was shown to be ineffective in the POSEIDON trial, raising further doubts regarding the significance of this disease state. A meta-analysis of 28 studies of AKI after CT with radiocontrast showed no causal relationship between the use of radiocontrast and AKI.
- Barrett BJ, Parfrey PS (2006). "Clinical practice. Preventing nephropathy induced by contrast medium". N. Engl. J. Med. 354 (4): 379–86. doi:10.1056/NEJMcp050801. PMID 16436769.
- Subramaniam, RM; Suarez-Cuervo, C; Wilson, RF; Turban, S; Zhang, A; Sherrod, C; Aboagye, J; Eng, J; Choi, MJ; Hutfless, S; Bass, EB (February 2016). "Effectiveness of Prevention Strategies for Contrast-Induced Nephropathy: A Systematic Review and Meta-analysis". Annals of Internal Medicine. 164 (6): 406–16. doi:10.7326/M15-1456. PMID 26830221.
- Aycock, Ryan D.; Westafer, Lauren M.; Boxen, Jennifer L.; Majlesi, Nima; Schoenfeld, Elizabeth M.; Bannuru, Raveendhara R. (August 2017). "Acute Kidney Injury After Computed Tomography: A Meta-analysis". Annals of Emergency Medicine. 71 (1): 44–53.e4. doi:10.1016/j.annemergmed.2017.06.041. PMID 28811122.
- McDonald, Robert; McDonald, Jennifer S.; Carter, Rickey E.; Hartman, Robert P.; Katzberg, Richard W.; Kallmes, David F.; Williamson, Eric E. (December 2014). "Intravenous Contrast Material Exposure Is Not an Independent Risk Factor for Dialysis or Mortality". Radiology. 273 (3): 714–725. doi:10.1148/radiol.14132418. PMID 25203000.
- Ellis, JH; Davenport, MS; Dillman, JR; Hartman, RP; Herts, BR; Jafri, SZ; Kolbe, AB; Laroia, A; Cohan, RH; MacDonald, RJ; Needleman, L; Newhouse, JH; Pahade, JK; Sirlin, CB; Wang, CL; Wasserman, N; Weinreb, JC (2017). ACR Manual on Contrast Media. American College of Radiology. pp. 35–46. ISBN 978-1-55903-012-0. Retrieved 24 October 2017.
- Nyman, Ulf; Ahlkvist, Joanna; Aspelin, Peter; Brismar, Torkel; Frid, Anders; Hellström, Mikael; Liss, Per; Sterner, Gunnar; Leander, Peter (2018). "Preventing contrast medium-induced acute kidney injury". European Radiology. 28 (12): 5384–5395. doi:10.1007/s00330-018-5678-6. ISSN 0938-7994. PMID 30132106.
- Mehran R, Aymong ED, Nikolsky E, et al. (2004). "A simple risk score for prediction of contrast-induced nephropathy after percutaneous coronary intervention: development and initial validation". J. Am. Coll. Cardiol. 44 (7): 1393–9. doi:10.1016/j.jacc.2004.06.068. PMID 15464318.
- Kalgi Modi, Scott C. Dulebohn (2017). Contrast-Induced Nephropathy. StatPearls Publishing. StatPearls Publishing. CC-BY-4.0
- Yang, Xiaoming; Hiremath, Swapnil; Akbari, Ayub; Shabana, Wael; Fergusson, Dean A.; Knoll, Greg A. (2013). "Prevention of Contrast-Induced Acute Kidney Injury: Is Simple Oral Hydration Similar To Intravenous? A Systematic Review of the Evidence". PLoS ONE. 8 (3): e60009. Bibcode:2013PLoSO...860009H. doi:10.1371/journal.pone.0060009. ISSN 1932-6203. PMC 3608617. PMID 23555863.
- Subramaniam, RM; Suarez-Cuervo, C; Wilson, RF; Turban, S; Zhang, A; Sherrod, C; Aboagye, J; Eng, J; Choi, MJ; Hutfless, S; Bass, EB (15 March 2016). "Effectiveness of Prevention Strategies for Contrast-Induced Nephropathy: A Systematic Review and Meta-analysis". Annals of Internal Medicine. 164 (6): 406–16. doi:10.7326/m15-1456. PMID 26830221.
- Sinert R, Doty CI (2007). "Evidence-based emergency medicine review. Prevention of contrast-induced nephropathy in the emergency department". Annals of Emergency Medicine. 50 (3): 335–45, 345.e1–2. doi:10.1016/j.annemergmed.2007.01.023. PMID 17512638.
- Bagshaw SM, Ghali WA (2005). "Theophylline for prevention of contrast-induced nephropathy: a systematic review and meta-analysis". Arch. Intern. Med. 165 (10): 1087–93. doi:10.1001/archinte.165.10.1087. PMID 15911721.
- Gleeson TG, Bulugahapitiya S (2004). "Contrast-induced nephropathy". AJR Am J Roentgenol. 183 (6): 1673–89. doi:10.2214/ajr.183.6.01831673. PMID 15547209.
- Kellum J, Leblanc M, Venkataraman R (2006). "Renal failure (acute)". Clinical Evidence (15): 1191–212. PMID 16973048.
- Sadat U, Usman A, Gillard JH, Boyle JR (2013). "Does ascorbic acid protect against contrast-induced acute kidney injury in patients undergoing coronary angiography: a systematic review with meta-analysis of randomized, controlled trials". J Am Coll Cardiol. 62 (23): 2167–75. doi:10.1016/j.jacc.2013.07.065. PMID 23994417.
- "Archived copy". Archived from the original on 2010-12-17. Retrieved 2010-12-14.CS1 maint: Archived copy as title (link), CorMedix June 25, 2010 Press Release, "CorMedix Doses First Patient in Phase II Clinical Trial of CRMD-001"
- "Deferiprone for the Prevention of Contrast-Induced Acute Kidney Injury". ClinicalTrials.gov.
- , ClinicalTrials.gov,"Evaluation of RenalGuard® System to Reduce the Incidence of Contrast Induced Nephropathy in At-Risk Patients (CIN-RG)"
- Marenzi, Giancarlo; Bartorelli, A (2012). "Prevention of Contrast Nephropathy by Furosemide With Matched Hydration". J Am Coll Cardiol Intv. 5 (1): 90–97. doi:10.1016/j.jcin.2011.08.017. PMID 22230154.
- Marenzi, Giancarlo; Ferrari, Cristina; Marana, Ivana; Assanelli, Emilio; Metrio, Monica De; Teruzzi, Giovanni; Veglia, Fabrizio; Fabbiocchi, Franco; Montorsi, Piero (2012). "Prevention of Contrast Nephropathy by Furosemide With Matched Hydration". JACC: Cardiovascular Interventions. 5 (1): 90–97. doi:10.1016/j.jcin.2011.08.017. PMID 22230154.
- Briguori, Carlo; Visconti, Gabriella; Focaccio, Amelia; Airoldi, Flavio; Valgimigli, Marco; Sangiorgi, Giuseppe Massimo; Golia, Bruno; Ricciardelli, Bruno; Condorelli, Gerolama (2011-09-13). "Renal Insufficiency After Contrast Media Administration Trial II (REMEDIAL II)Clinical Perspective: RenalGuard System in High-Risk Patients for Contrast-Induced Acute Kidney Injury". Circulation. 124 (11): 1260–1269. doi:10.1161/CIRCULATIONAHA.111.030759. ISSN 0009-7322. PMID 21844075.
- Barbanti, Marco; Gulino, Simona; Capranzano, Piera; Immè, Sebastiano; Sgroi, Carmelo; Tamburino, Claudia; Ohno, Yohei; Attizzani, Guilherme F.; Patanè, Martina (2015). "Acute Kidney Injury With the RenalGuard System in Patients Undergoing Transcatheter Aortic Valve Replacement". JACC: Cardiovascular Interventions. 8 (12): 1595–1604. doi:10.1016/j.jcin.2015.07.012. PMID 26386766.
- Usmiani, Tullio; Andreis, Alessandro; Budano, Carlo; Sbarra, Pierluigi; Andriani, Monica; Garrone, Paolo; Fanelli, Anna Laura; Calcagnile, Chiara; Bergamasco, Laura (2016). "AKIGUARD (Acute Kidney Injury GUARding Device) trial". Journal of Cardiovascular Medicine. 17 (7): 530–537. doi:10.2459/jcm.0000000000000348. PMID 26702595.
- Putzu, Alessandro; Berto, Martina Boscolo; Belletti, Alessandro; Pasotti, Elena; Cassina, Tiziano; Moccetti, Tiziano; Pedrazzini, Giovanni (2017). "Prevention of Contrast-Induced Acute Kidney Injury by Furosemide With Matched Hydration in Patients Undergoing Interventional Procedures". JACC: Cardiovascular Interventions. 10 (4): 355–363. doi:10.1016/j.jcin.2016.11.006. PMID 28231903.
- Mattathil, Stephanie; Ghumman, Saad; Weinerman, Jonathan; Prasad, Anand (2017-10-01). "Use of the RenalGuard system to prevent contrast-induced AKI: A meta-analysis". Journal of Interventional Cardiology. 30 (5): 480–487. doi:10.1111/joic.12417. ISSN 1540-8183. PMID 28870002.
- Brar, Somjot S.; Aharonian, Vicken; Mansukhani, Prakash; Moore, Naing; Shen, Albert Y.-J.; Jorgensen, Michael; Dua, Aman; Short, Lindsay; Kane, Kevin (2014-05-24). "Haemodynamic-guided fluid administration for the prevention of contrast-induced acute kidney injury: the POSEIDON randomised controlled trial". Lancet. 383 (9931): 1814–1823. doi:10.1016/S0140-6736(14)60689-9. ISSN 1474-547X. PMID 24856027.
- "Medscape". www.medscape.com. Retrieved 2017-09-28.