Contrast and the Kidneys
Consent for Nephropathy
We are asking that you have a test to help us decide whether you have a serious condition causing your symptoms. The test requires giving you IV dye that could put stress on your kidneys. In a small number of patients, this stress can lead to major kidney damage, and needing dialysis. The risk is higher when there are signs of kidney weakness in blood tests or in someone with diabetes. There are several treatments that have been shown to reduce this risk, but the number of patients that benefit from them is small. The treatments are safe but may cause a 1- to 2-hour delay in doing the test and in making the diagnosis. (Ann Emerg Med 2008;51(4))
This trial suggests it is the illness, not the contrast that leads to renal failure in the crit ill (CCM 2013;41:1017)
Intravenous contrast material exposure is not an independent risk factor for dialysis or mortality
Radiology. 2014 Dec;273(3):714-25. doi: 10.1148/radiol.14132418. Epub 2014 Sep 9. . McDonald RJ1, McDonald JS, Carter RE, Hartman RP, Katzberg RW, Kallmes DF, Williamson EE. Author information Abstract PURPOSE: To determine the risk of emergent dialysis and short-term mortality following intravenous iodinated contrast material exposure. MATERIALS AND METHODS: This single-center retrospective study was HIPAA compliant and institutional review board approved. All contrast material-enhanced (contrast group) and unenhanced (noncontrast group) abdominal, pelvic, and thoracic computed tomography scans from 2000-2010 were identified. Patients in the contrast and noncontrast groups were compared following propensity score-based 1:1 matching to reduce intergroup selection bias. Patients with preexisting diabetes mellitus, congestive heart failure, or chronic or acute renal failure were identified as high-risk patient subgroups for nephrotoxicity. The effects of contrast material exposure on the rate of acute kidney injury ( AKI acute kidney injury ) (serum creatinine level ≥ 0.5 mg/dL [44.2 μmol/L] above baseline within 24-72 hours of exposure) and dialysis or death within 30 days of exposure were determined by using odds ratios ( OR odds ratio s) and covariate-adjusted Cox proportional hazards models. Results were validated with a bootstrapped sensitivity analysis. RESULTS: The 1:1 matching on the basis of the propensity score yielded a cohort of 21 346 patients (10 673 in the contrast group, 10 673 in the noncontrast group). Within this cohort, the risks of AKI acute kidney injury ( OR odds ratio , 0.94; 95% confidence interval [ CI confidence interval ]: 0.83, 1.07; P = .38), emergent dialysis ( OR odds ratio , 0.96; 95% CI confidence interval : 0.54, 1.60; P = .89), and 30-day mortality (hazard ratio [ HR hazard ratio ], 0.97; 95% CI confidence interval : 0.87, 1.06; P = .45) were not significantly different between the contrast group and the noncontrast group. Although patients who developed AKI acute kidney injury had higher rates of dialysis and mortality, contrast material exposure was not an independent risk factor for either outcome for dialysis ( OR odds ratio , 0.89; 95% CI confidence interval : 0.40, 2.01; P = .78) or for mortality ( HR hazard ratio , 1.03; 95% CI confidence interval : 0.82, 1.32; P = .63), even among patients with compromised renal function or predisposing comorbidities. CONCLUSION: Intravenous contrast material administration was not associated with excess risk of AKI acute kidney injury , dialysis, or death, even among patients with comorbidities reported to predispose them to nephrotoxicity. © RSNA, 2014 Online supplemental material is available for this article. PMID: 25203000
Screening for Renal Failure
Screening Cr not necessary prior to CT, Screen for following risk factors instead, history of renal insufficiency, Diabetes Mellitus, on chemotherapy, Solitary Kidney. (Are Screening Serum Cr Levels Necessary prior to Outpatient CT Examinations? Radiology 216:2, 2000.)
BUN is inordinately sensitive
Based on evaluation of the receiver operating characteristic curve constructed in the derivation set, the sensitivity for renal insufficiency at BUN cut-offs of 15mg/dl and 20mg/dl was 99.5% and 96%, respectively. When this model was applied to the validation set, the sensitivity and specificity of a BUN cut-off of 15mg/dl were 99.7% and 56%, respectively (negative predictive value, 99.9%; negative likelihood ratio, 0.005). At a BUN cut-off of 20mg/dl, the sensitivity and specificity for renal insufficiency were 98% and 71%, respectively (negative predictive value, 99.4%; negative likelihood ratio, 0.03) (Am J Emerg Med 21(6):494, October 2003)
Seafood Allergies and Other Myths
best article (CJEM 2003;5(3):166-8)
excellent blog post from Salem Rezie
seafood is no more predictive than asthma or any other food allergy (6%)
hives at any point in life were more predictive (7%)
pretreatment with steroids may help
Also see (AJR 1997;169:906-908)
The New EMedHome Clinical Pearl is: Radiocontrast, Iodine, and Seafood Allergies
Radiocontrast, Iodine, and Seafood Allergies
- Asking if patients are allergic to shellfish or iodine has no relevance to radiocontrast allergies. Iodine cannot be an allergen – it is found throughout our bodies in thyroid hormones and amino acids and is added to most salt used in the US. Both fish and shellfish contain iodine, but it is not the source of people’s allergies. The major allergens in shellfish are muscle proteins, tropomyosins (1,2).
- Reactions to IV contrast are anaphylactoid, not allergic and therefore not anaphylactic (3). These reactions are not caused by IgE and thus require no pre-exposure. Nearly all life-threatening reactions to IV contrast occur immediately or within the first 20 min after contrast media injection (1).
- Although prior allergic reaction to seafood, shellfish, or iodine-containing solutions would create IgE sensitized to those allergens, this sensitized IgE would play no role in a reaction to IV contrast media, since the reaction to contrast is not IgE mediated. For the same reason, a patient who had an adverse event after contrast injection is unlikely to experience a similar or more severe reaction if given contrast again – non-immune-mediated means no immune system memory. (1,3-5).
- The risk of reactions to contrast media in patients with seafood allergy is similarly elevated (about a 3-fold relative risk) for persons with allergy to egg, milk or chocolate, indicating that a general atopic disposition, rather than an iodine-specific reactivity, accounts for the increased incidence of reactions in this sub-group. Thus, reactions to contrast media should not be construed as an indication of an IgE antibody-mediated iodine allergy (1,4).
- Do not delay emergent studies for steroid premedication. Only lengthy 12 hour premedication protocols have shown any effect on reaction rates, and this small benefit was manifested primarily by decreasing minor reactions. No steroid protocol has shown a statistically significant improvement in severe adverse reaction rates (1).
References:(1) Schabelman E, et al. The Relationship of Radiocontrast, Iodine, and Seafood Allergies: A Medical Myth Exposed J Emerg Med 2009 Dec 31. [Epub ahead of print].(2) Leung PS, et al. Seafood allergy: tropomyosins and beyond J Microbiol Immunol Infect 1999;32:143154. (3) American College of Radiology. Manual on contrast media. Reston, VA: American College of Radiology; 2008. (4) American Academy of Allergy Asthma and Immunology. The risk of severe allergic reactions from the use of potassium iodide for radiation emergencies. Milwaukee, WI: American Academy of Allergy Asthma and Immunology; 2004. (5) Mishkin MM. Contrast media safety: what do we know and how do we know it? Am J Cardiol 1990;66:34F36F.
Oral Contrast
30 cc gastrograffin in 1 liter of sterile water
Do not use barium in emergent situations
bacteria love barium, mix it with feces and it is a perfect bacterial broth
the barium does not move through gi tract for days
Duke’s reasons for not using oral
NAC
ACETYLCYSTEINE AND CONTRAST AGENT-ASSOCIATED NEPHROTOXICITY Click here to hear the Reviewer’s comments via RealAudio Briguori, C., et al, J Am Coll Card 40(2):298, July 17, 2002 did not do anything if >140 of contrast, 1.52-1.48 in aceytl 1.53-154 in non
ROLE OF N-ACETYLCYSTEINE IN THE PREVENTION OF RADIOCONTRAST-INDUCED NEPHROPATHY Click here to hear the Reviewer’s comments via RealAudio Brophy, D.F., Ann Pharmacother 36:1466, September 2002 BACKGROUND: In hospitalized patients, development of radiocontrast-induced nephropathy (RIN) is associated with substantial morbidity and a more than five-fold increase in the risk of dying during the hospital stay. Risk factors for RIN include preexisting renal dysfunction, diabetes, chronic heart failure, dehydration, and the use of large contrast volumes and high-osmolar contrast. The pathophysiology of RIN is multifactorial, and oxygen-free radicals have been implicated as playing a potential role. Peri-procedural administration of hypotonic saline has been reported to be protective, but studies of other prophylactic strategies have yielded disappointing results. It is speculated that the antioxidant properties of N-acetylcysteine (NAC) may be protective. METHODS: The author from Virginia Commonwealth University, discusses two randomized controlled trials (total 137 patients) of the effects of oral NAC (four 600mg doses) on the development of RIN in patients with chronic renal insufficiency, who also received hypotonic saline RESULTS: In both trials, RIN was significantly more frequent in the control groups than in the NAC groups (21% vs. 2% and 45% vs 8%), and the effects of NAC were particularly notable in patients with baseline serum creatinine levels above 2.0 or 2.5mg/dl. Study limitations included small sample sizes, use of low-osmolar contrast, concomitant use of potentially protective calcium channel blockers, inclusion of some patients at relatively low risk and in one study, limitation of follow-up to 48 hours. CONCLUSIONS Given the evidence suggesting a beneficial effect of NAC in preventing RIN, its relatively low cost, and its fairly innocuous adverse effect profile, the author feels that its use is appropriate in high-risk patients, but acknowledges the need for further trials. 28 references
Metaanalysis
Am J Card 92:1454, December 15, 2003 NAC prophylaxis was associated with a statistical reduction in the development of contrast nephropathy, defined as a creatinine increase exceeding 0.5mg/dl or 25% of baseline values at 48 hours (summary odds ratio 0.37, 95% confidence interval [CI] 0.16-0.84), with a number-need-to-treat of nine (95% CI 5- 33). The overall rate of contrast nephropathy was 13.3%, while the dialysis rate was 0.75% either with or without NAC. CONCLUSIONS: Based on the impact of NAC prophylaxis on this surrogate marker, the authors suggest its routine use in stable patients undergoing elective imaging. 20 references (daniel.isenbarger@na.amedd.army.mil)
N-ACETYLCYSTEINE FOR RADIOCONTRAST-INDUCED NEPHROPATHY: POTENTIAL ROLE IN THE EMERGENCY DEPARTMENT? Click here to hear the Reviewer’s comments via MP3. Chong, E., et al, Can J Emerg Med 6(4):253, July 2004 BACKGROUND: A need for urgent contrast-enhanced imaging in ED patients may preclude a careful assessment of the risk for radiocontrast-induced nephropathy (RIN) or adequate prophylactic hydration. It has been suggested that N-acetylcysteine, a potent vasodilator that enhances renal perfusion, prevents ischemia-reperfusion syndromes and may protect against the effects of circulating free radicals, might be an effective agent for RIN prophylaxis. METHODS: The authors, from the University of British Columbia and Virtual Learning, Inc., in Toronto, conducted a systematic review of nine randomized, controlled studies (1,019 patients) of the effects of prophylactic N-acetylcysteine for the prevention of RIN. RESULTS: Five of the nine trials reported a renoprotective effect of N- acetylcysteine prophylaxis, and four did not. However, seven of the nine trials involved prophylaxis prior to elective imaging, and only two could potentially be extrapolated to the ED setting. One reported that an aggressive regimen of IV N-acetylcysteine (150mg/kg given over 30 minutes prior to imaging followed by 50mg/kg/hr for four hours) in patients with stable chronic renal failure reduced the rate of contrast-induced renal dysfunction (4.9% vs. 20.5% in controls) at the expense of an increase in the rate of adverse effects. In the second trial, a 1200mg dose of oral N- acetylcysteine given one hour prior to, and three hours after, contrast administration was not renoprotective. CONCLUSIONS: The authors feel that the available evidence does not support the use of N-acetylcysteine prophylaxis to protect against RIN in patients requiring urgent contrast- enhanced imaging. 20 references (zed@interchange.ubc.ca)
-
Acetylcysteine for Prevention of Renal Outcomes in Patients Undergoing Coronary and Peripheral Vascular Angiography: Main Results From the Randomized Acetylcysteine for Contrast-Induced Nephropathy Trial (ACT).
-
Conclusions- In this large randomized trial, we found that acetylcysteine does not reduce the risk of contrast-induced acute kidney injury or other clinically relevant outcomes in at-risk patients undergoing coronary and peripheral vascular angiography. Clinical Trial Registration- http://www.clinicaltrials.gov. Unique identifier: NCT00736866.
New RCT showed no benefit of NAC, but amount of saline seemed to correlate with avoidance of CIN (Ann Emerg Med 2013;62:511)
Sodium Bicarb
Bicarb significantly reduced contrast-induced nephropathy.
Qualified patients who agreedto enter the study were sequentially assigned to 1 of 2 treatmentgroups by the pharmacy based on a computer-generated randomizationschedule. Patients allocated to the sodium chloride group received154 mEq/L of sodium chloride in 5% dextrose and H2O. Patientsallocated to the sodium bicarbonate group received 154 mEq/Lof sodium bicarbonate in dextrose and H2O, mixed in the hospitalpharmacy by adding 154 mL of 1000 mEq/L sodium bicarbonate to846 mL of 5% dextrose in H2O, slightly diluting the dextroseconcentration to 4.23%.
After appropriate nursing evaluation and initial measurementof blood pressure and weight, the precontrast fluid was administered. The initial intravenous bolus was 3 mL/kg per hour for 1 hour immediately before radiocontrast injection. Following this,patients received the same fluid at a rate of 1 mL/kg per hourduring the contrast exposure and for 6 hours after the procedure.For patients weighing more than 110 kg, the initial fluid bolusand drip were limited to those doses administered to a patientweighing 110 kg. Diuretics were routinely held on the day ofcontrast injection. A basic metabolic panel of serum chemistrieswas obtained on the morning of the procedure and on postproceduredays 1 and 2, and until any increase of serum creatinine resolved.Urinary pH was measured after infusion of the bolus when thepatient next spontaneously voided. No diuretics were administeredafter a patient received contrast.
(JAMA Vol. 291 No. 19, May 19, 2004)
sodium bicarbonate 154mEq/L (3 ampules in 1 liter D5W) 3mL/kg/hr IV for 1 hour before contrast 1mL/kg/hr IV for 6 hours after contrast
Risk Score for CIN
(J Am Coll Cardio 2004;44(7):1393)
HD Patients with ESRD do not need immediate HD post contrast
- Younathan CM, Kaude JV, Cook MD, Shaw GS, Peterson JC. Dialysis is not indicated immediately after administration of nonionic contrast agents in patients with end-stage renal disease treated by maintenance dialysis. AJR Am J Roentgenol. 1994 Oct;163(4):969-71.
- Hamani A, Petitclerc T, Jacobs C, Deray G. Is dialysis indicated immediately after administration of iodinated contrast agents in patients on haemodialysis? Nephrol Dial Transplant. 1998 Apr;13(4):1051-2.
- Morcos SK, Thomsen HS, Webb JA; Contrast Media Safety Committee of the European Society of Urogenital Radiology (ESUR). Dialysis and contrast media. Eur Radiol. 2002 Dec;12(12):3026-30.
- Dawson P. Contrast agents in patients on dialysis. Semin Dial. 2002 Jul-Aug;15(4):232-6.
- Deray G. Dialysis and iodinated contrast media. Kidney Int Suppl. 2006 Apr;(100):S25-9.
Extravisation
ionic or concentrated contrast material can severe injuries, but the newer dilute non-ionic rarely causes problems
Best article (Cohan, Radiology 1196;200(3):593)
much greater chance of problems with metal butterfly needles as opposed to catheters.
dorsum of hand and foot can have problems from amount of ccs in small space
Phlebitis can cause extravisation even whent he tip is in the vein, as larger catheters eventually weaken the vascular wall
Elevate the extremity and cool it with ice for 20-30 minutes
May need fasciotomy if compartment syndrome develops
Can get a plain radiograph to see the degree of extravisation
EFFECT OF LOW DOSES OF IONISING RADIATION IN INFANCY ON COGNITIVE FUNCTION IN ADULTHOOD: SWEDISH POPULATION BASED COHORT Click here to hear the Reviewer’s comments via MP3. Hall, P., et al, Br Med J 328:1, January 3, 2004
Metformin
Salpeter SR, Greyber E, Pasternak GA, Salpeter (posthumous) EE. Risk of fatal and nonfatal lactic acidosis with
metformin use in type 2 diabetes mellitus. Cochrane Database of Systematic Reviews 2010, Issue 1. Art. No.: CD002967. DOI:
10.1002/14651858.CD002967.pub3.