Contrast-induced nephropathy in patients with renal insufficiency undergoing contrast-enhanced MDCT

Effects of Low-Osmolar Contrast Media on Long-Term Renal Impairment After Coronary Angiography: Iohexol Versus Iopromide

To investigate the long-term effects of 2 commonly used low-osmolar contrast media, iohexol and iopromide, on renal function and survival in patients who underwent coronary angiography. A total of 14,141 cardiology patients from 2006 to 2013 were recruited, of whom 1,793 patients (679 patients on iohexol and 1,114 on iopromide) were evaluated for long-term renal impairment and 5,410 patients (1,679 patients on iohexol and 3,731 on iopromide) were admitted for survival analyses spanning as long as 15 years. Univariate and multivariate logistic regression were used to explore the risk factors for long-term renal impairment. Cox proportional hazard regression was used to investigate the risk factors affecting survival. Propensity score matching and inverse probability of treatment weighting were applied to balance the baseline clinical characteristics. Patients receiving iohexol demonstrated a greater occurrence of renal impairment compared with those who received iopromide. Such difference remained consistent both before and after propensity score matching or inverse probability of treatment weighting, with a statistical significance of p <0.05. Among clinical variables, receiving contrast-enhanced contrast tomography/magnetic resonance imaging during follow-up, antihypertensive medication usage, presence of proteinuria, and anemia were identified as risk factors for long-term renal impairment (p = 0.041, 0.049, 0.006, and 0.029, respectively). During survival analyses, the difference was insignificant after propensity score matching and inverse probability of treatment weighting. In conclusion, administration of iohexol was more likely to induce long-term renal impairment than iopromide, particularly among patients diagnosed with anemia and proteinuria and those taking antihypertensive medication and with additional contrast exposure. The all-cause mortality, however, showed no significant difference between iohexol and iopromide administration.

Patients with Different Stages of Chronic Kidney Disease Undergoing Intravenous Contrast-Enhanced Computed Tomography-The Incidence of Contrast-Associated Acute Kidney Injury

Introduction: Iodinated contrast medium (CM) is the third most common cause of acute kidney injury (AKI). However, the association is poorly known between the definitions of AKI between different stages of chronic kidney disease after intravenous CM administration. Methods: The dataset, covering a period of ~15 years (1 June 2008 to 31 March 2015), consisted of 20,018 non-dialytic adult patients who had received intravenous injections of non-ionic iso-osmolar CM, iodixanol, for enhanced computed tomography imaging. Contrast-associated AKI (CA-AKI), dialysis-required AKI, and mortality were analyzed. Results: A total of 12,271 participants were enrolled. CA-AKI increased significantly starting from stage 3A onward (p < 0.001). In summary, incidences of CA-AKI against different levels of chronic kidney disease were as follows: stage 1 (8.3%) = stage 2 (6.7%) < stage 3A (9.9%) < stage 3B (14.3%) < stage 4 (20.5%) = stage 5 (20.4%). The incidences of dialysis within 30 days were as follows: stage 1 (1%) = stage 2 (1.4%) = stage 3A (2.7%) < stage 3B (5.7%) < stage 4 (18%) < stage 5 (54.1%). The prediction of dialysis was good based on the baseline serum creatinine > 1.5 mg/dL (72.78% of sensitivity, 86.07% of specificity, 0.851 of area under curve) or baseline estimated glomerular filtration rate ≤ 38.49 mL/min/1.732 m2 (70.19% of sensitivity, 89.08% of specificity, 0.853 of area under curve). In multivariate Cox regression analysis model for CA-AKI, independent risk factors were stage 4 chronic kidney disease (p = 0.001) and shock (p = 0.001). Conclusion: Baseline serum creatinine and estimated glomerular filtration rate were good predictors for dialysis-required AKI. CA-AKI increased significantly since stage 3A chronic kidney disease. Stage 4 and 5 chronic kidney disease have the same risk for CA-AKI, but stage 5 chronic kidney disease has markedly higher risk for dialysis.

Contrast associated nephropathy after intravenous administration: what is the magnitude of the problem?

Intravenous contrast media (CM) is often used in clinical practice to enhance CT scan imaging. For many years, contrast-induced nephropathy (CIN) was thought to be a common occurrence and to result in dire consequences. When treating patients with abnormal renal function, it is not unusual that clinicians postpone, cancel, or replace contrast-enhanced imaging with other, perhaps less informative tests. New studies however have challenged this paradigm and the true risk attributable to intravenous CM for the occurrence of CIN has become debatable. In this article, we review the latest relevant medical literature and aim to provide an evidence-based answer to questions surrounding the risk, outcomes, and potential mitigation strategies of CIN after intravenous CM administration.

Creatinine level variation in patients subjected to contrast-enhanced tomography: a meta-analysis

Variation in the creatinine levels of patients who have undergone contrast-enhanced computed tomography (CT) has been adopted as a practical method for assessment of possible kidney damage caused by the contrast. Criteria employed include an absolute increase in serum creatinine ≥ 0.5 mg/dL or a relative increase ≥ 25% as indicative of possible renal disorders, such as contrast-induced nephropathy (CIN). Our objective was to analyze the incidence of CIN by means of a meta-analysis of nine articles related to incidence of kidney damage caused by contrast, calculating odds ratios (OR) and confidence intervals (95%CI) using RStudio. The overall incidence of CIN in patients who had CT scans was 11.29%, with an OR of 1.38 (95%CI 0.88–2.16). Non-ionic contrasts are safer than other types of contrast, and volumes exceeding 115 mL may be associated with CIN. Preexisting kidney disease had a statistically significant relationship with worse CIN rates.

Renal Function-Adjusted D-Dimer Levels in Critically Ill Patients With Suspected Thromboembolism

OBJECTIVES

Diagnosing thromboembolic disease typically includes D-dimer testing and use of clinical scores in patients with low to intermediate pretest probability. However, renal dysfunction is often observed in patients with thromboembolic disease and was previously shown to be associated with increased D-dimer levels. We seek to validate previously suggested estimated glomerular filtration rate-adjusted D-dimer cutoff levels. Furthermore, we strive to explore whether the type of renal dysfunction affects estimated glomerular filtration rate-adjusted D-dimer test characteristics.

DESIGN

Single-center retrospective data analysis from electronic healthcare records of all emergency department patients admitted for suspected thromboembolic disease.

SETTING

Tertiary care academic hospital.

SUBJECTS

Exclusion criteria were as follows: age less than 16 years old, patients with active bleeding, and/or incomplete records.

INTERVENTIONS

Test characteristics of previously suggested that estimated glomerular filtration rate-adjusted D-dimer cutoff levels (> 333 µg/L [estimated glomerular filtration rate, > 60 mL/min/1.73 m], > 1,306 µg/L [30-60 mL/min/1.73 m], and > 1,663 µg/L [< 30 mL/min/1.73 m]) were validated and compared with the conventional D-dimer cutoff level of 500 µg/L.

MAIN RESULTS

A total of 14,477 patients were included in the final analysis, with 467 patients (3.5%) diagnosed with thromboembolic disease. Renal dysfunction was observed in 1,364 (9.4%) of the total population. When adjusted D-dimer levels were applied, test characteristics remained stable: negative predictive value (> 99%), sensitivity (91.2% vs 93.4%), and specificity (42.7% vs 50.7%) when compared with the conventional D-dimer cutoff level to rule out thromboembolic disease (< 500 µg/L). Comparable characteristics were also observed when adjusted D-dimer cutoff levels were applied in patients with acute kidney injury (negative predictive value, 98.8%; sensitivity, 95.8%; specificity, 39.2%) and/or "acute on chronic" renal dysfunction (negative predictive value, 98.0%; sensitivity, 92.9%; specificity, 48.5%).

CONCLUSIONS

D-Dimer cutoff levels adjusted for renal dysfunction appear feasible and safe assessing thromboembolic disease in critically ill patients. Furthermore, adjusted D-dimer cutoff levels seem reliable in patients with acute kidney injury and "acute on chronic" renal dysfunction. In patients with estimated glomerular filtration rate less than 60 mL/min/1.73 m, the false-positive rate can be reduced when estimated glomerular filtration rate-adjusted D-dimer cutoff levels are applied.

Uric acid and contrast-induced nephropathy: an updated review and meta-regression analysis

Introduction

Previous studies have suggested a relationship between serum uric acid and contrast-induced nephropathy (CIN).

Aim

We performed an updated review and a meta-regression analysis to assess whether serum uric acid is associated with CIN or there exists any relationship between serum uric acid and other risk factors for CIN.

Material and methods

We searched PubMed, Embase and Cochrane databases and reviewed cited references up to July 31, 2018 to identify relevant studies.

Results

A total of 6,705 patients from 10 clinical studies were included. CIN occurred in 774 of the 6,705 (12%) patients. Baseline uric acid levels were significantly higher in those who developed CIN (6.51 vs. 5.67 mg/dl; 95% CI: 0.55–1.22, p = 0.00001). Comparison of clinical features showed that patients with CIN were significantly older (69 vs. 63 years; p < 0.00001) and more often had diabetes (42% vs. 32%; p = 0.002) and hypertension (67% vs. 59%; p = 0.03). Also, patients who developed CIN had lower hemoglobin (12.5 vs. 13.6 mg/dl; p < 0.00001) and higher levels of baseline creatinine (1.27 vs. 1.01 mg/dl; p < 0.0001), but had similar levels of glycemia, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride. Also, they showed a lower ejection fraction (45% vs. 50%; p < 0.00001). Meta-regression analysis revealed that uric acid related only to age (r = 0.13, p = 0.03).

Conclusions

Our investigation indicates that uric acid is significantly associated with CIN. Uric acid correlated significantly with age only, and not with other major predictors of CIN. Further studies are therefore needed to verify the potential of uric acid to improve CIN risk stratification.

Spot Sign in Acute Intracerebral Hemorrhage in Magnetic Resonance Imaging: A Case Report and Review of the Literature

INTRODUCTION

Intracranial hemorrhage (ICH) is associated with significant mortality and morbidity. Current treatment paradigms focus on correcting hypertension and coagulopathy to prevent hematoma expansion. Magnetic resonance imaging (MRI) is becoming more common in the hyperactive phase of ICH management. The finding of contrast extravasation (ie, spot sign) on MRI may be a marker of active bleeding. We present a case of MRI spot sign and review of the literature.

CASE REPORT

We present a patient on oral coumadin for history of deep venous thrombosis and pulmonary embolus who presented with a right basal ganglia hemorrhage. She had a computed tomography angiography showing contrast extravasation and also had a hyperacute MRI showing similar contrast extravasation. Follow-up imaging showed hematoma enlargement.

DISCUSSION

We present here a case of corroboration of the computed tomography angiography spot sign with the MRI spot sign. The prognostic value of the MRI spot sign is unclear. Future studies should evaluate the prognostic value of the hyperacute MRI in ICH management.

Critical Limb Ischemia: A Practical Up-To-Date Review

Critical limb ischemia (CLI) is the most advanced form of peripheral artery disease. It is associated with significant morbidity and mortality and high management costs. It carries a high risk of amputation and local infection. Moreover, cardiovascular complications remain a major concern. Although it is a well-known entity and new technological and therapeutic advances have been made, this condition remains poorly addressed, with significantly heterogeneous management, especially in nonexperienced centers. This review, from a third-level dedicated inpatient and outpatient cardioangiology structure, aims to provide an updated summary on the topic of CLI of its complexity, encompassing epidemiological, social, economical and, in particular, diagnostic/imaging issues, together with potential therapeutic strategies (medical, endovascular, and surgical), including the evaluation of cardiovascular risk factors, the diagnosis, and treatment together with prognostic stratification.

Acute Kidney Injury After Computed Tomography: A Meta-analysis

STUDY OBJECTIVE

Computed tomography (CT) is an important imaging modality used in the diagnosis of a variety of disorders. Imaging quality may be improved if intravenous contrast is added, but there is a concern for potential renal injury. Our goal is to perform a meta-analysis to compare the risk of acute kidney injury, need for renal replacement, and total mortality after contrast-enhanced CT versus noncontrast CT.

METHODS

We searched MEDLINE (PubMed), the Cochrane Library, CINAHL, Web of Science, ProQuest, and Academic Search Premier for relevant articles. Included articles specifically compared rates of renal insufficiency, need for renal replacement therapy, or mortality in patients who received intravenous contrast versus those who received no contrast.

RESULTS

The database search returned 14,691 articles, inclusive of duplicates. Twenty-six unique articles met our inclusion criteria, with an additional 2 articles found through hand searching. In total, 28 studies involving 107,335 participants were included in the final analysis, all of which were observational. Meta-analysis demonstrated that, compared with noncontrast CT, contrast-enhanced CT was not significantly associated with either acute kidney injury (odds ratio [OR] 0.94; 95% confidence interval [CI] 0.83 to 1.07), need for renal replacement therapy (OR 0.83; 95% CI 0.59 to 1.16), or all-cause mortality (OR 1.0; 95% CI 0.73 to 1.36).

CONCLUSION

We found no significant differences in our principal study outcomes between patients receiving contrast-enhanced CT versus those receiving noncontrast CT. Given similar frequencies of acute kidney injury in patients receiving noncontrast CT, other patient- and illness-level factors, rather than the use of contrast material, likely contribute to the development of acute kidney injury.

Prediction of presence of kidney disease in patients undergoing intravenous iodinated contrast enhanced computed tomography: a validation study

OBJECTIVES

To validate two previously presented models containing risk factors to identify patients with estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2 or eGFR <45 ml/min/1.73 m2.

METHODS

In random patients undergoing intravenous contrast-enhanced computed tomography (CECT) the following risk factors were assessed: history of urological/nephrological disease, hypertension, diabetes mellitus, anaemia, congestive heart failure, other cardiovascular disease or multiple myeloma or Waldenström disease. Data on kidney function, age, gender and type and indication of CECT were also registered. We studied two models: model A-diabetes mellitus, history of urological/nephrological disease, cardiovascular disease, hypertension; model B-diabetes mellitus, history of urological/nephrological disease, age >75 years and congestive heart failure. For each model, associations with eGFR <60 ml/min/1.73 m2 or eGFR <45 ml/min/1.73 m2 was studied.

RESULTS

A total of 1,001 patients, mean age 60.36 years were included. In total, 92 (9.2 %) patients had an eGFR <60 ml/min/1.73 m2 and 11 (1.1 %) patients an eGFR <45 ml/min/1.73 m2. Model A detected 543 patients: 81 with eGFR <60 ml/min/1.73 m2 (missing 11) and all 11 with eGFR <45 ml/min/1.73 m2. Model B detected 420 patients: 70 (missing 22) with eGFR <60 ml/min/1.73 m2 and all 11 with eGFR <45 ml/min/1.73 m2. Associations were significant (p < 0.05).

CONCLUSIONS

Model B resulted in the lowest superfluous eGFR measurements while detecting all patients with eGFR <45 ml/min/1.73 m2 and nearly all with eGFR <60 ml/min/1.73 m2.

KEY POINTS

• Less than 10% of patients undergoing contrast-enhanced CT have an eGFR of <60ml/min/1.73m 2 • Four risk factors can be used to detect pre-existent kidney disease • It is safe to reduce eGFR measurements using a four-risk-factor model.

Is gender still a predisposing factor in contrast-media associated adverse drug reactions? A systematic review and meta-analysis of randomized trials and observational studies

OBJECTIVE

To evaluate the role of gender as a risk factor for developing contrast media-associated adverse drug reactions (CM-ADRs) by comparing the incidence of CM-ADR between male and female patients according to study design, ADR type, and computed tomography (CT) examination.

MATERIAL AND METHODS

We systematically searched three electronic databases for eligible studies. In the studies included (n=18), we assessed effect estimates of the relative incidence of CM-ADR, analysed by experimental design, ADR type and CT examination. This was calculated by using a random effects model if clinical conditions showed heterogeneity; otherwise, a fixed effects model was used.

RESULTS

We identified 10,776 patients administered CM. According to the designs, studies were classified into randomised controlled trials (RCTs) and observational studies. Results were as follows: risk ratio (RR)=1.07 (95% confidence interval (CI): 0.79-1.46, P=0.66) for RCTs, and RR=0.77 (95% CI: 0.58-1.04, P=0.09) for observational studies. The results of analysis according to ADR type and for undergoing CT demonstrated that the incidence of CM-ADR did not differ between males and females.

CONCLUSIONS

We found no significant difference in the incidence of CM-ADRs between male and female patients according to study design, ADR type, or CT examination. Future studies to determine why gender has shown different roles as a risk factor between CM-ADRs and non-CM ADRs are needed.

Contrast-Induced Nephropathy After Computed Tomography in Stable CKD Patients With Proper Prophylaxis: 8-Year Experience of Outpatient Prophylaxis Program

Conflicting data have been reported on the clinical significance of contrast-induced nephropathy after CT scan (CT-CIN). In addition, the epidemiologic characteristics and clinical outcomes of CT-CIN following proper prophylactic intervention remain elusive.We examined the incidence, risk factors, and outcomes of CT-CIN in stable chronic kidney disease (CKD) patients using data collected from our outpatient CT-CIN prophylaxis program conducted between 2007 and 2014. The program recruited patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m using an electronic health record-based pop-up alert system and provided an identical protocol of CIN prophylaxis to all patients.A total of 1666 subjects were included in this study, and 61 of the 1666 subjects (3.7%) developed CT-CIN. Multivariate analysis showed that baseline eGFR, diabetes mellitus, and low serum albumin were significant risk factors for CT-CIN. The generalized additive model analysis revealed a nonlinear relationship between the baseline eGFR and the risk of CT-CIN. In this analysis, the risk of CT-CIN began to increase below an eGFR threshold of 36.8 mL/min/1.73 m. To assess the outcomes of CT-CIN, patients with and without CT-CIN were compared after propensity score-based 1:2 matching. CT-CIN did not increase the mortality rate of patients. However, patients with CT-CIN were significantly more likely to start dialysis within 6 months of follow-up, but not after those initial 6 months.CT-CIN developed in only a small number of stable CKD patients who received proper prophylactic intervention, and the risk of CT-CIN was increased in patients with more advanced CKD. Despite the low incidence, CT-CIN conferred a non-negligible risk for the initiation of dialysis in the acute period, even after prophylaxis.

Contrast-induced nephropathy in CT: incidence, risk factors and strategies for prevention

In the past, a high percentage of hospital-acquired renal failure was attributed to contrast media. That position is now very controversial. Recently, doubts have been raised regarding the real relationship between acute kidney injury and intravenous contrast media administration. Similarly, statements about specific methods of preventing contrast-inducing nephropathy have been challenged. This review article addresses the controversies of incidence, causation, and prevention in an attempt to help the practicing radiologist adopt methods for their own department.

KEY POINTS

• The reported CIN incidence ranges from 2-12 % following contrast-enhanced CT. • Studies without a non-contrast CT control group may overestimate CIN incidence. • Development and application of a comprehensive CIN prevention strategy is recommended.

Improved outcome with combined US/CT guidance as compared to US guidance in percutaneous radiofrequency ablation of small renal masses

BACKGROUND

When performing percutaneous radiofrequency ablation (RFA) of small renal masses (SRM), use of optimized periprocedural image guidance is essential to secure curative outcome of the treatment.

PURPOSE

To retrospectively compare the short-term radiological and clinical outcomes of RFA under combined ultrasound (US) and computed tomography (CT) guidance with that of a previously performed US-guided series at the same institution.

MATERIAL AND METHODS

From November 2009 to November 2013, 60 patients (mean age, 70.1 years; range, 34-86 years) with renal masses measuring in the range of 13-50 mm in maximal diameter (mean diameter, 25.4 ± 6.8 mm) underwent percutaneous RFA with combined US/CT guidance. The technical success rate, recurrence-free survival, rate of complications, and the percentage change in the estimated glomerular filtration rate (eGFR) were compared with that of a previously published series of 41 patients with SRM treated with US-guided RFA between November 2002 and December 2008.

RESULTS

The tumor and patient characteristics were similar between the two treatment groups. The primary and secondary technical success rate was significantly higher in the group treated with combined US/CT guidance compared with the group treated with US guidance alone (100% and 100% vs. 82% and 91%, respectively). The local recurrence-free survival was significantly better in the combined US/CT-guided group than in the US-guided group (P = 0.016). There was no significant difference in the rate of overall complications (13% vs. 17%) or the mean percentage decrease in the eGFR after the respective treatment (1.1 ± 18.3% vs. 5.0 ± 11.7%).

CONCLUSION

The use of combined US/CT guidance when performing renal RFA resulted in superior primary and short-term outcome compared to the use of US guidance alone in patients treated at the same institution.

The efficacy of sodium bicarbonate in preventing contrast-induced nephropathy in patients with pre-existing renal insufficiency: a meta-analysis

OBJECTIVE

The aim of this meta-analysis was to explore the efficacy of sodium bicarbonate in preventing contrast-induced nephropathy (CIN).

METHODS

We searched PubMed, Medline and the Cochrane Library from 1 January 2004 to 1 August 2014. The effect estimate was expressed as a pooled OR with 95% CI, using the fixed-effects or random-effects model.

RESULTS

20 randomised controlled trials (n=4280) were identified. Hydration with sodium bicarbonate was associated with a significant decrease in CIN among patients with pre-existing renal insufficiency (OR 0.67, 95% CI 0.47 to 0.96; p=0.027). However, moderate heterogeneity was noted across trials (I(2)=48%; p=0.008). Subgroup analyses indicated a better effect of sodium bicarbonate in studies using low-osmolar (OR 0.59, 95% CI 0.37 to 0.93; p=0.024) compared with iso-osmolar contrast agents (OR 0.76, 95% CI 0.43 to 1.34; p=0.351). The odds of CIN with sodium bicarbonate were lower in studies including only patients undergoing emergency (OR 0.16, 95% CI 0.05 to 0.51; p=0.002) compared with elective procedures (OR 0.76, 95% CI 0.54 to 1.06; p=0.105). Sodium bicarbonate was more beneficial in patients given a bolus injection before procedures (OR 0.15, 95% CI 0.04 to 0.54; p=0.004) compared with continuous infusion (OR 0.75, 95% CI 0.53 to 1.05; p=0.091). Sodium bicarbonate plus N-acetylcysteine (OR 0.17, 95% CI 0.04 to 0.79; p=0.024) was better than sodium bicarbonate alone (OR 0.71, 95% CI 0.48 to 1.03; p=0.071). The effect of sodium bicarbonate was considered greater in papers published before (OR 0.19, 95% CI 0.09 to 0.41; p=0.000) compared with after 2008 (OR 0.85, 95% CI 0.62 to 1.16; p=0.302). However, no significant differences were found in mortality (OR 0.69, 95% CI 0.36 to 1.32; p=0.263) or requirement for dialysis (OR 1.08, 95% CI 0.52 to 2.25; p=0.841).

CONCLUSIONS

Sodium bicarbonate is effective in preventing CIN among patients with pre-existing renal insufficiency. However, it fails to lower the risks of dialysis and mortality and therefore cannot improve the clinical prognosis of patients with CIN.

Does intravenous contrast-enhanced computed tomography cause acute kidney injury? Protocol of a systematic review of the evidence

BACKGROUND

Contrast-induced acute kidney injury is a common cause of iatrogenic acute kidney injury (AKI). Most of the published estimates of AKI after contrast use originate from the cardiac catheterization literature despite contrast-enhanced computed tomography (CT) scans being the more common setting for contrast use. This systematic review aims to summarize the current evidence about (1)the risk of AKI following intravenous (IV) contrast-enhanced CT scans and(2) the risk of clinical outcomes (i.e. death, hospitalization and need for renal replacement therapy) due to IV contrast-enhanced CT scans.

METHODS/DESIGN

A systematic literature search for published studies will be performed using MEDLINE, EMBASE and The COCHRANE Library databases. Unpublished studies will be identified by searching through grey literature. No language restriction will be applied.The review will consider all studies that have examined the association between IV contrast media and AKI. To be selected, the study should include two arms: one group of exposed patients who received IV contrast material before CT scans and one group of unexposed group who did not receive contrast material before CT scans. Two authors will independently screen titles and abstracts obtained from electronic databases, extract data and will assess the quality of the studies selected using the Cochrane's 'Risk of Bias' assessment tool for randomized trials and the Newcastle-Ottawa Scale for observational studies. A random-effects meta-analysis will be performed if there is no remarkable heterogeneity between studies.

DISCUSSION

This systematic review will provide synthesis of current evidence around the effect of IV contrast material on AKI and other clinical outcomes. Results will be helpful for making evidence-based recommendations and guidelines for clinical and radiologic settings.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42013003799.

Prediction of presence of kidney disease in a general patient population undergoing intravenous iodinated contrast enhanced computed tomography

OBJECTIVE

To assess which risk factors can be used to reduce superfluous estimated glomerular filtration rate (eGFR) measurements before intravenous contrast medium administration.

METHODS

In consecutive patients, all decreased eGFR risk factors were assessed: diabetes mellitus (DM), history of urologic/nephrologic disease (HUND), nephrotoxic medication, cardiovascular disease, hypertension, age > 60 years, anaemia, malignancy and multiple myeloma/M. Waldenström. We studied four models: (1) all risk factors, (2) DM, HUND, hypertension, age > 60 years; (3) DM, HUND, cardiovascular disease, hypertension; (4) DM, HUND, age > 75 years and congestive heart failure. For each model, association with eGFR < 60 ml/min/1.73 m(2) or eGFR < 45 ml/min/1.73 m(2) was studied.

RESULTS

A total of 998 patients, mean age 59.94 years were included; 112 with eGFR < 60 ml/min/1.73 m(2) and 30 with eGFR < 45 ml/min/1.73 m(2). Model 1 detected 816 patients: 108 with eGFR < 60 ml/min/1.73 m(2) and all 30 with eGFR < 45 ml/min/1.73 m(2). Model 2 detected 745 patients: 108 with eGFR < 60 ml/min/1.73 m(2) and all 30 with eGFR < 45 ml/min/1.73 m(2). Model 3 detected 622 patients: 100 with eGFR < 60 ml/min/1.73 m(2) and all 30 with eGFR < 45 ml/min/1.73 m(2). Model 4 detected 440 patients: 86 with eGFR < 60 ml/min/1.73 m(2) and all 30 with eGFR < 45 ml/min/1.73 m(2). Associations were significant (p < 0.001).

CONCLUSION

Model 4 is most effective, resulting in the lowest proportion of superfluous eGFR measurements while detecting all patients with eGFR < 45 ml/min/1.73 m(2) and most with eGFR < 60 ml/min/1.73 m(2).

KEY POINTS

A major risk factor for contrast-induced nephropathy (CIN) is kidney disease. Risk factors are used to identify patients with pre-existent kidney disease. Evidence for risk factors to identify patients with kidney disease is limited. The number of eGFR measurements to detect kidney disease can be reduced.

Fluctuations in eGFR in relation to unenhanced and enhanced MRI and CT outpatients

OBJECTIVE

To study fluctuations in estimated glomerular filtration rate (eGFR) in relation to contrast medium (CM) enhanced magnetic resonance imaging (MRI) and computed tomography (CT) compared to control groups in outpatients.

MATERIALS AND METHODS

eGFR was determined right before the imaging procedure and three days later at the department or at the patient's home. The iodine-based and gadolinium-based contrast media were the same as used for all other examinations at the department.

RESULTS

A total of 716 patients completed the study. There was a statistically significant, but not clinically relevant rise in eGFR after three days in all four groups. The average eGFR variation was 4.8 ml/min/1.73 m(2). There were large variations in eGFR between the two measurements in 45.8% of the patients as they had a change greater than ± 10 ml/min/1.73 m(2). Only three patients fulfilled the contrast-induced nephropathy (CIN) requirement when the definition s-creatinine ≥ 44 μmol/l (0.5mg/dl) was used.

CONCLUSIONS

eGFR in outpatients undergoing MRI or CT did vary independently of whether the patient received contrast or not. The findings probably reflect the natural variations in s-creatinine levels. This should be taken into consideration when CIN is studied.

Contrast alternatives for iodinated contrast allergy and renal dysfunction: options and limitations

Diagnostic angiography and vascular interventions make routine use of iodinated contrast material (ICM). Patients with renal disease or contrast allergy pose limitations on the use of ICM. In such cases, alternative contrast media may be used to carry out the procedure. Current alternatives include carbon dioxide, gadolinium, and dilute ICM. Each of these alternatives has its own unique features and limitations. In the present review article, the current alternatives to ICM are explored, with a focus on the applications and restrictions of each.