Prophylaxis of contrast material-induced nephropathy in patients in intensive care: acetylcysteine, theophylline, or both? A randomized study

Role of aminophylline in prevention of acute kidney injury in term neonates with severe perinatal asphyxia: a randomized open-label controlled trial

Acute kidney injury (AKI) is one of the frequently observed complications in neonates with severe perinatal asphyxia. The efficacy of aminophylline in preventing or alleviating renal dysfunction in these neonates remains controversial. The current study aimed to explore whether treatment with aminophylline as adjunctive therapy is superior to standard care alone in preventing AKI in severely asphyxiated term neonates and to delineate the changes in other renal parameters. In this open-label randomized clinical trial, term neonates with severe asphyxia (n = 41) received a 5 mg/kg intravenous dose of aminophylline within the first hour after birth, in addition to standard care for birth asphyxia. The control group (n = 40) received standard care alone. Their daily urine output, weight, serum creatinine, renal functional status, and complications during the first 5 days of life were monitored and compared. The statistical package for social sciences version 25 was used for analysis. Approximately 24.39% of neonates in the aminophylline group developed AKI, compared to 35.0% in the control group (P = .088). Although urine output was generally higher in aminophylline-treated newborns than in the control group, this increase was not statistically significant (P > .05), with the most notable differences observed on the second and third postnatal days. Also, the changes in plasma creatinine levels between the two groups during this time were not statistically significant. Administering a single dose of aminophylline (5 mg/kg) within the first hour of life to severely asphyxiated term neonates might temporarily enhance urine output, but does not reduce the overall incidence of AKI.

Adenosine antagonists for prevention of contrast-induced nephropathy: A meta-analysis of randomized controlled trials with trial sequential analysis

Contrast-induced nephropathy (CIN) is caused by intravascular administration of contrast agent. The efficacy of adenosine antagonists (AAs) in preventing CIN remains controversial, and its elucidation was the objective of the present meta-analysis. A trial sequential analysis (TSA) to assess the reliability of the pooled results was also performed. The Medline, Embase, Web of Science and Cochrane databases were searched to retrieve all published randomized controlled trials (RCTs) comparing AAs with controls in preventing CIN. Heterogeneity, publication bias and quality of studies were assessed. Sensitivity, cumulative and subgroup analyses were also performed. The risk of random errors was evaluated by TSA. A total of 17 trials with 1,483 subjects were included. Pooled results indicated that AAs significantly reduced the incidence of CIN [risk ratio, 0.53; 95% confidence interval (CI), 0.29-0.95; P=0.034] and the serum creatinine (SCr) level after contrast media (CM) administration (standardized mean difference, -0.24; 95% CI, -0.44 to -0.04; P=0.019). Meta-regression did not identify any significant source of heterogeneity. In the subgroup analyses, AAs tended to exhibit a greater prevention efficacy in trials with sample sizes of ≥70, baseline SCr of <1.5 mg/dl and low study quality. TSA on the incidence of CIN indicated that the required information size determined as n=1,778 was not reached, and that the cumulative Z-curve did not cross the TSA boundary. In conclusion, the present meta-analysis of data from current RCTs suggested that AAs reduce the incidence of CIN and the SCr levels after CM administration. However, TSA showed that the risk of having a false-positive result was greater than 5% in the meta-analysis of the incidence of CIN, indicating that more evidence is required to ensure the benefit of AAs in preventing CIN.

Effectiveness of contrast-associated acute kidney injury prevention methods; a systematic review and network meta-analysis

BACKGROUND

Different methods to prevent contrast-associated acute kidney injury (CA-AKI) have been proposed in recent years. We performed a mixed treatment comparison to evaluate and rank suggested interventions.

METHODS

A comprehensive Systematic review and a Bayesian network meta-analysis of randomised controlled trials was completed. Results were tabulated and graphically represented using a network diagram; forest plots and league tables were shown to rank treatments by the surface under the cumulative ranking curve (SUCRA). A stacked bar chart rankogram was generated. We performed main analysis with 200 RCTs and three analyses according to contrast media and high or normal baseline renal profile that includes 173, 112 & 60 RCTs respectively.

RESULTS

We have included 200 trials with 42,273 patients and 44 interventions. The primary outcome was CI-AKI, defined as ≥25% relative increase or ≥ 0.5 mg/dl increase from baseline creatinine one to 5 days post contrast exposure. The top ranked interventions through different analyses were Allopurinol, Prostaglandin E1 (PGE1) & Oxygen (0.9647, 0.7809 & 0.7527 in the main analysis). Comparatively, reference treatment intravenous hydration was ranked lower but better than Placebo (0.3124 VS 0.2694 in the main analysis).

CONCLUSION

Multiple CA-AKI preventive interventions have been tested in RCTs. This network evaluates data for all the explored options. The results suggest that some options (particularly allopurinol, PGE1 & Oxygen) deserve further evaluation in a larger well-designed RCTs.

Contrast-Induced Nephropathy: Update on the Use of Crystalloids and Pharmacological Measures

Contrast-induced nephropathy (CIN) is a frequent and severe complication in subjects receiving iodinated contrast media for diagnostic or therapeutic purposes. Several preventive strategies were evaluated in the past. Recent clinical studies and meta-analyses delivered some new aspects on preventive measures used in the past and present. We will discuss all pharmacological and nonpharmacological procedures. Finally, we will suggest individualized recommendations for CIN prevention.

Contrast-induced acute kidney injury in kidney transplant recipients: A systematic review and meta-analysis

AIM

To evaluate the incidence of contrast-induced acute kidney injury (CIAKI) in kidney transplant recipients.

METHODS

A literature search was performed using MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews from the inception of the databases through July 2016. Studies assessing the incidence of CIAKI in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of CIAKI.

RESULTS

Six studies of 431 kidney transplant recipients were included in the analyses to assess the incidence of CIAKI in kidney transplant recipients. The estimated incidence of CIAKI and CIAKI-requiring dialysis were 9.6% (95%CI: 4.5%-16.3%) and 0.4% (95%CI: 0.0%-1.2%), respectively. A sensitivity analysis limited only to the studies that used low-osmolar or iso-osmolar contrast showed the estimated incidence of CIAKI was 8.0% (95%CI: 3.5%-14.2%). The estimated incidences of CIAKI in recipients who received contrast media with cardiac catheterization, other types of angiogram, and CT scan were 16.1% (95%CI: 6.6%-28.4%), 10.1% (95%CI: 4.2%-18.0%), and 6.1% (95%CI: 1.8%-12.4%), respectively. No graft losses were reported within 30 d post-contrast media administration. However, data on the effects of CIAKI on long-term graft function were limited.

CONCLUSION

The estimated incidence of CIAKI in kidney transplant recipients is 9.6%. The risk stratification should be considered based on allograft function, indication, and type of procedure.

Periprocedural Nebivolol for the Prevention of Contrast-Induced Acute Kidney Injury: A Systematic Review and Meta-analysis

Background:

Nebivolol provides a protective effect on contrast-induced acute kidney injury (CIAKI) in animal models. However, the reports on the efficacy of nebivolol for the prevention of CIAKI in human remain unclear.

Aims:

The objective of this meta-analysis was to assess the effect of nebivolol for the prevention of CIAKI.

Materials and Methods:

Comprehensive literature searches were performed using MEDLINE, EMBASE, and Cochrane Database from inception through February 2015. Studies that reported relative risks, odd ratios, or hazard ratios comparing the risk of CIAKI in patients who received nebivolol versus those who did not were included. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

Results:

Four studies (2 randomized controlled trials and 2 cohort studies) with 543 patients were included in our analysis to assess the risk of CIAKI and the use of nebivolol. Patients in the nebivolol group had an overall lower incidence of CIAKI (14.4%) compared to the control group (18.4%). The pooled RR of CIAKI in patients receiving nebivolol was 0.66 (95% CI: 0.38-1.15, I² = 0). When meta-analysis was limited only to randomized control trials (RCTs), the pooled RR of CIAKI in patients receiving nebivolol was 0.79 (95% CI: 0.35-1.79, I² = 0%).

Conclusions:

Despite no statistical significance, there was a trend toward reduced CIAKI risk in patients receiving nebivolol. The findings of our meta-analysis suggest the need of a large RCT with very careful attention to the balance of benefits and harms.

Incidence and outcome of contrast-associated acute kidney injury assessed with Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) criteria in critically ill patients of medical and surgical intensive care units: a retrospective study

Background

Contrast medium used for radiologic tests can decrease renal function. However there have been few studies on contrast-associated acute kidney injury in intensive care unit (ICU) patients. The objective of this study was to evaluate the incidence, characteristics, and outcome of contrast-associated acute kidney injury (CA-AKI) patients using the Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) criteria in critically ill patients in the ICU.

Methods

We conducted a retrospective study of adult patients who underwent contrast-enhanced radiologic tests from January 2011 to December 2012 in a 30-bed medical ICU and a 24-bed surgical ICU.

Results

The study included 335 patients, and the incidence of CA-AKI was 15.5%. The serum creatinine and estimated glomerular filtration rate values in the CA-AKI patients did not recover even at discharge from the hospital compared with the values prior to the contrast use. Among 52 CA-AKI patients, 55.8% (n = 29) had pre-existing kidney injury and 44.2% (n = 23) did not. The CA-AKI patients were divided into risk (31%), injury (31%), and failure (38%) by the RIFLE classification. The percentage of patients in whom AKI progressed to a more severe form (failure, loss, end-stage kidney disease) increased from 38% to 45% during the hospital stay, and the recovery rate of AKI was 17% at the time of hospital discharge. Because the Acute Physiology and Chronic Health Evaluation (APACHE) II score was the only significant variable inducing CA-AKI, higher APACHE II scores were associated with a higher risk of CA-AKI. The ICU and hospital mortality of patients with CA-AKI was significantly higher than in patients without CA-AKI.

Conclusions

CA-AKI is associated with increases in hospital mortality, and can be predicted by the APACHE score.

Trial registration

NCT01807195 on March. 06. 2013.

Periprocedural effects of statins on the incidence of contrast-induced acute kidney injury: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The reports on the efficacy of statins for the prevention of contrast-induced acute kidney injury (CIAKI) remain controversial. The objective of this meta-analysis was to assess the effect of statins for the prevention of CIAKI.

METHODS

Comprehensive literature searches for randomized controlled trials (RCTs) of periprocedural statin treatment for prevention of CIAKI were performed using MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials Systematic Reviews and clinicaltrials.gov from inception until May 2014. The primary outcome was the incidence of CIAKI.

RESULTS

Thirteen prospective RCTs were included in our analysis. Of 5803 patients with contrast exposures, 304 patients (5.2%) had CIAKI. Patients in the statin group had an overall lower incidence of CIAKI (3.6%) compared to the control group (6.9%). Intravenous (IV) fluid hydration was used in both groups of all included studies for prevention of CIAKI. There was a significant protective effect of periprocedural statins on the incidence of CIAKI when compared to the control group [risk ratios (RRs): 0.49; 95% CI: 0.37-0.66, I(2) of 25%].

CONCLUSIONS

Our study demonstrates a statistically significant protective effect of statin treatment during procedures with contrast exposures. This finding suggests the use of statins in addition to standard IV crystalloid hydration may be beneficial in the prevention of CIAKI.

Oral hydration for prevention of contrast-induced acute kidney injury in elective radiological procedures: a systematic review and meta-analysis of randomized controlled trials

Background:

The reports on efficacy of oral hydration treatment for the prevention of contrast-induced acute kidney injury (CIAKI) in elective radiological procedures and cardiac catheterization remain controversial.

Aims:

The objective of this meta-analysis was to assess the use of oral hydration regimen for prevention of CIAKI.

Materials and Methods:

Comprehensive literature searches for randomized controlled trials (RCTs) of outpatient oral hydration treatment was performed using MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials Systematic Reviews, and clinicaltrials.gov from inception until July 4^th, 2014. Primary outcome was the incidence of CIAKI.

Results:

Six prospective RCTs were included in our analysis. Of 513patients undergoing elective procedures with contrast exposures,45 patients (8.8%) had CIAKI. Of 241 patients with oral hydration regimen, 23 (9.5%) developed CIAKI. Of 272 patients with intravenous (IV) fluid regimen, 22 (8.1%) had CIAKI. Study populations in all included studies had relatively normal kidney function to chronic kidney disease (CKD) stage 3. There was no significant increased risk of CIAKI in oral fluid regimen group compared toIV fluid regimen group (RR = 0.94, 95% confidence interval, CI = 0.38-2.31).

Conclusions:

According to our analysis,there is no evidence that oral fluid regimen is associated with more risk of CIAKI in patients undergoing elective procedures with contrast exposures compared to IV fluid regimen. This finding suggests that the oral fluid regimen might be considered as a possible outpatient treatment option for CIAKI prevention in patients with normal to moderately reduced kidney function.

Intravenous magnesium sulfate: new method in prevention of contrast-induced nephropathy in primary percutaneous coronary intervention

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) is an adverse consequence of percutaneous coronary interventions which results in significant morbidity and mortality and adds to the costs of diagnostic and interventional cardiology procedures. Various pathophysiological mechanisms have been proposed for CI-AKI and various agents tested for its prevention. There is currently a general agreement that adequate pre-procedural hydration constitutes the cornerstone of prevention, yet there are reports of the use of some other agents with various efficacies. We prospectively tested IV magnesium sulfate (Mg) for CI-AKI prevention.

METHOD AND DESIGN

This study is a prospective, randomized, open-labeled, single-center clinical trial. We randomly assigned 122 consecutive patients to two groups. The first group was the control group with routine treatment (n = 64), and second group was the study group with routine treatment plus IV magnesium sulfate 1 g just before the procedure (n = 62). Serum creatinine was measured before the procedure and 2 days after the procedure. The primary end point was the occurrence of CI-AKI within 48 h. CI-AKI was defined as 0.5 mg/dl or more increase in serum creatinine or 25% or more increase above baseline serum creatinine. There was no difference in definition if both of these parameters were present.

RESULTS

The control and study groups were comparable in the overall predicted risk of CI-AKI. Also, the type and volume of the contrast were not significantly different between the two groups. Following angioplasty, CI-AKI occurred in 17 (26.6%) patients in the control group and nine (14.5%) patients in the study group; there was a significant reduction in CI-AKI in the study group (P = 0.01). Additionally, there was no mortality or a need for hemodialysis in either group.

CONCLUSION

In primary PCI patients, the prophylactic use of intravenous Mg can be recommended to be added to traditional hydration for CI-AKI prevention.

Pharmacological strategies to prevent contrast-induced acute kidney injury

Contrast-induced acute kidney injury (CI-AKI) is the most common iatrogenic cause of acute kidney injury after intravenous contrast media administration. In general, the incidence of CI-AKI is low in patients with normal renal function. However, the rate is remarkably elevated in patients with preexisting chronic kidney disease, diabetes mellitus, old age, high volume of contrast agent, congestive heart failure, hypotension, anemia, use of nephrotoxic drug, and volume depletion. Consequently, CI-AKI particularly in high risk patients contributes to extended hospitalizations and increases long-term morbidity and mortality. The pathogenesis of CI-AKI involves at least three mechanisms; contrast agents induce renal vasoconstriction, increase of oxygen free radicals through oxidative stress, and direct tubular toxicity. Several strategies to prevent CI-AKI have been evaluated in experimental studies and clinical trials. At present, intravascular volume expansion with either isotonic saline or sodium bicarbonate solutions has provided more consistent positive results and was recommended in the prevention of CI-AKI. However, the proportion of patients with risk still develops CI-AKI. This review critically evaluated the current evidence for pharmacological strategies to prevent CI-AKI in patients with a risk of developing CI-AKI.

Radiographic contrast-media-induced acute kidney injury: pathophysiology and prophylactic strategies

Contrast-induced acute kidney injury (CI-AKI) is one of the most widely discussed and debated topics in cardiovascular medicine. With increasing number of contrast-media- (CM-) enhanced imaging studies being performed and growing octogenarian population with significant comorbidities, incidence of CI-AKI remains high. In this review, pathophysiology of CI-AKI, its relationship with different types of CM, role of serum and urinary biomarkers for diagnosing CI-AKI, and various prophylactic strategies used for nephroprotection against CI-AKI are discussed in detail.

Acute kidney injury in the critically ill: is iodinated contrast medium really harmful?

OBJECTIVES

To assess whether the use of iodinated contrast medium increases the incidence of acute kidney injury in ICU patients, compared with patients not receiving iodinated contrast medium.

DESIGN

Prospective observational matched cohort study.

SETTING

Two ICUs in two tertiary teaching hospitals.

PATIENTS

A total of 380 adults were included (20% more than once), before an iodinated contrast medium infusion (contrast inclusions, n=307) or before an intrahospital transfer without iodinated contrast medium infusion (control inclusions, n=170).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among contrast inclusions, iodinated contrast medium-associated acute kidney injury occurred after 23 administrations (7.5%) according to the Acute Kidney Injury Network definition (stage≥1, over 48 hr). As expected, a broader definition (≥25% increase in serum creatinine over 72 hr) yielded a greater incidence (16%). In 146 pairs of contrast and control inclusions, matched on propensity for iodinated contrast medium infusion, the incidence of acute kidney injury was similar (absolute difference in incidence, 0%; 95% confidence interval, -5.2; 5.2%), Acute Kidney Injury Network definition). Hospital mortality was also similar in 71 contrast and 71 control patients included only once and matched the same way. Contrary to iodinated contrast medium infusion (odds ratio, 1.57; 95% confidence interval, 0.69-3.53), the Sequential Organ Failure Assessment score at inclusion (odds ratio, 1.18; 95% confidence interval, 1.07-1.31) and the number of other nephrotoxic agents (odds ratio, 1.38; 95% confidence interval, 1.03-1.85) were independent risk factors for acute kidney injury.

CONCLUSIONS

The specific toxic effect of monomeric nonionic low-osmolar iodinated contrast medium in ICU patients with multiple renal aggressions seemed minimal. Severity of disease and the global nephrotoxic burden were risk factors for acute kidney injury, regardless of iodinated contrast medium infusion.

Accuracy of plasma neutrophil gelatinase-associated lipocalin in the early diagnosis of contrast-induced acute kidney injury in critical illness

PURPOSE

Neutrophil gelatinase-associated lipocalin (NGAL) is a promising biomarker for acute kidney injury (AKI). We evaluated the diagnostic and prognostic accuracies of plasma NGAL (pNGAL) for contrast-induced AKI (CI-AKI) in critically ill patients.

METHODS

In a prospective observational study in two adult intensive care units in a university hospital, 100 consecutive critically ill patients with stable serum creatinine concentrations up to 48 h before contrast medium (CM) injection were enrolled. Serial blood sampling for pNGAL analysis was performed at enrolment, 2, 6, and 24 h after CM injection. The primary outcome was CI-AKI, defined by AKIN criteria, within the first 72 h following CM injection. Secondary outcomes were the need for renal replacement therapy (RRT) and mortality.

RESULTS

Of the 98 patients analyzed, 30 developed CI-AKI. The pNGAL levels did not differ in patients with or without CI-AKI, and were higher in septic patients compared to nonseptic patients, and in patients with AKI preceding CM injection. The discriminative value of pNGAL to predict CI-AKI and mortality was poor; although, it did predict the need for RRT requirement after CM injection (area under receiver-operating characteristic curve, 0.85, 0.80, 0.83 and 0.86 at H0, H2, H6 and H24, respectively).

CONCLUSION

CI-AKI was common in critically ill patients. pNGAL levels were higher in patients with sepsis or previous AKI, but did not help to diagnose CI-AKI any earlier than serum creatinine after CM injection. However, pNGAL could be of interest to detect patients at risk of subsequent RRT requirement.

Risk of contrast induced nephropathy in the critically ill: a prospective, case matched study

Introduction

Computerized tomography is frequently employed in the critically ill, often using intravenous radiocontrast material. Many of these patients have clinical features that are considered risk factors for contrast induced nephropathy, but are simultaneously at risk for renal injury from other factors related to their acute illnesses. The attributable risk for renal dysfunction from radiocontrast exposure has not been well quantified in this population.

Methods

A prospective matched cohort study was conducted of patients scanned with or without radiocontrast enhancement while receiving intensive care in a Veterans Affairs Medical Center. Patients were matched for pre-scan measured creatinine clearance, diabetes, mechanical ventilation, and vasopressor use. Measured clearance was followed for three days after scanning. Evolution of nephropathy, as determined by change in measured clearance, was compared within matched pairs.

Results

Fifty-three pairs of patients satisfied matching criteria. Unmatched characteristics were similar among the pairs, including serum creatinine variability during the week preceding scanning (67 ± 85% among contrast recipients, 63 ± 62% among others) and clinical risk factors for renal failure. In 29 pairs, pre-scan measured clearances were less than 60 mL/minute/1.73 m². Following scanning, measured clearance declined by at least 33% in 14 contrast and 19 non-contrast patients (95% confidence interval for contrast associated difference in nephropathy rates -27% to 9%), while a 50% reduction in clearance persisted three days after scanning in three contrast and nine non-contrast patients (95% confidence interval for difference in rates -25% to 2%).

Conclusions

Among established intensive care unit patients declines in glomerular filtration following contrast-enhanced scanning are common, but these changes are far more likely to be attributable to factors other than the contrast exposure itself. The upper bound for the incidence of contrast induced renal injury lasting even three days was 2% in the population studied.

Renal replacement therapy in ICU

Diagnosing and managing critically ill patients with renal dysfunction is a part of the daily routine of an intensivist. Acute kidney insufficiency substantially contributes to the morbidity and mortality of critically ill patients. Renal replacement therapy (RRT) not only does play a significant role in the treatment of patients with renal failure, acute as well as chronic, but also has spread its domains to the treatment of many other disease conditions such as myaesthenia gravis, septic shock and acute on chronic liver failure. This article briefly outlines the role of renal replacement therapy in ICU.

Contrast-induced nephropathy: attributable incidence and potential harm

Contrast-induced nephropathy is a common form of hospital-acquired acute kidney injury. Incidence is low in patients with normal renal function but increases in high-risk patients. Patients with contrast-induced nephropathy have higher in-hospital complication rates and mortality. Critically ill patients have been assumed to be a high-risk group for contrast-induced nephropathy. In the previous issue of Critical Care, Cely and colleagues showed an unexpectedly low incidence of contrast-induced nephropathy in critically ill patients receiving radiographic contrast material for computerized tomography. We should note that it is difficult to establish the true frequency and impact of the contrast nephrotoxicity because of many other causes for acute kidney injury in this population. Moreover, the impact on long-term kidney function and the possible effect of this insult on the recovery of renal function when associated with other causes of acute kidney injury are unknown.

Effect of theophylline on prevention of contrast-induced acute kidney injury: a meta-analysis of randomized controlled trials

BACKGROUND

Whether treatment with adenosine receptor antagonists such as theophylline can prevent contrast-induced acute kidney injury (AKI) remains controversial.

STUDY DESIGN

We conducted a meta-analysis of randomized controlled trials using MEDLINE (1966 to July 2011), EMBASE (1980 to July 2011), Web of Science (1986 to July 2011), and the Cochrane Central Register of Controlled Trials (1996 to July 2011), without language restriction.

SETTING & POPULATION

Patients undergoing contrast procedures.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials assessing adenosine antagonists versus control for prevention of contrast-induced AKI.

INTERVENTION

Adenosine antagonists with or without N-acetylcysteine versus control with or without N-acetylcysteine.

OUTCOMES

Contrast-induced AKI, change in serum creatinine level, requirement of dialysis, and in-hospital mortality.

RESULTS

16 trials (1,412 participants) were included. Theophylline significantly decreased the risk of contrast-induced AKI (13 trials, 1,222 patients; risk ratio, 0.48; 95% CI, 0.26-0.89; P = 0.02; I(2) = 45%) and had a protective effect on the absolute change in serum creatinine concentration (13 trials, 1,170 patients; standardized mean difference, -0.31 mg/dL; 95% CI, -0.50 to -0.11; P = 0.002; I(2) = 60%). Meta-regression showed a significant relation between the relative risk of contrast nephropathy and baseline serum creatinine level or Jadad score. No clear effects of treatment on risk of dialysis and in-hospital mortality were identified.

LIMITATIONS

Power to assess clinical end points was limited.

CONCLUSIONS

Theophylline treatment significantly reduced the incidence of contrast-induced AKI and had a modest improvement on kidney function after contrast exposure in the general population. However, beneficial effects of theophylline were not observed in patients with high baseline creatinine values (serum creatinine ≥1.5 mg/dL). In addition, the long-term effect of this agent on more clinically important outcomes was not established. Future large-scale high-quality multicenter trials in participants with different underlying risks of contrast-induced AKI and that incorporate the evaluation of clinically relevant outcomes are required.

Outcome of critically ill patients with acute kidney injury using the Acute Kidney Injury Network criteria

OBJECTIVE

Acute kidney injury affects 5% to 7% of all hospitalized patients with a much higher incidence in the critically ill. The Acute Kidney Injury Network proposed a definition in which serum creatinine rises (>0.3 mg/dL) and/or oliguria (<0.5 mL/kg/hr) for a period of 6 hrs are used to detect acute kidney injury. Accurate urine output measurements as well as serum creatinine values from our database were used to detect patients with acute kidney injury and calculate their corresponding mortality risk and length of stay.

DESIGN

Retrospective cohort study.

SETTING

Seven intensive care units at a large, academic, tertiary medical center.

PATIENTS

Adult patients without evidence of end-stage renal disease with more than two creatinine measurements and at least a 6-hr urine output recording who were admitted to the intensive care unit between 2001 and 2007.

INTERVENTIONS

Medical records of all the patients were reviewed. Demographic information, laboratory results, charted data, discharge diagnoses, physiological data, and patient outcomes were extracted from the Multiparameter Intelligent Monitoring in Intensive Care II database using a SQL query.

MEASUREMENTS AND MAIN RESULTS

From 19,677 adult patient records, 14,524 patients met the inclusion criteria. Fifty-seven percent developed acute kidney injury during their intensive care unit stay. Inhospital mortality rates were: 13.9%, 16.4%, 33.8% for acute kidney injury 1, 2, and 3, respectively, compared with only 6.2% in patients without acute kidney injury (p < .0001). After adjusting for multiple covariates, acute kidney injury was associated with increased hospital mortality (odds ratio 1.4 and 1.3 for acute kidney injury 1 and acute kidney injury 2 and 2.5 for acute kidney injury 3; p < .0001). Using multivariate logistic regression, we found that in patients who developed acute kidney injury, urine output alone was a better mortality predictor than creatinine alone or the combination of both.

CONCLUSIONS

More than 50% of our critically ill patients developed some stage of acute kidney injury resulting in a stagewise increased mortality risk. However, the mortality risk associated with acute kidney injury stages 1 and 2 does not differ significantly. In light of these findings, re-evaluation of the Acute Kidney Injury Network staging criteria should be considered.

Epidemiology of contrast-associated acute kidney injury in ICU patients: a retrospective cohort analysis

PURPOSE

Intensive care unit (ICU) patients frequently undergo contrast-enhanced radiographic examinations, which carries a risk for development of contrast-associated acute kidney injury (CA-AKI). Data on this in ICU patients are scarce. The aim of this study was therefore to evaluate the epidemiology and short- and long-term outcomes of CA-AKI in ICU patients.

METHODS

A retrospective single-centre cohort study covering the period 1 March 2004 to 31 December 2008 on ICU patients who underwent a radiography examination with parenteral administration of iodinated radio contrast media was conducted. Data analysis included univariate and multivariate analyses of patients with and without CA-AKI.

RESULTS

A total of 787 ICU patients were included in the study. CA-AKI occurred in 128 (16.3%) and was associated with higher need for RRT [30 (4.6%) vs. 21 (16.4%), p < 0.001], worse kidney function at discharge, longer length of ICU and hospital stay, and higher 28-day and 1-year mortality [28-day: 86 (13.1%) vs. 46 (35.9%), p < 0.001, and 1-year: 158 (24.0%) vs. 71 (55.5%), p < 0.001]. Higher serum creatinine, lower mean arterial pressure, and administration of diuretics and vasoactive therapy were associated with development of CA-AKI in multivariate analysis. After correction for confounders we found that CA-AKI was associated with 28-day mortality in this cohort of ICU patients (odds ratio = 2.742, 95% confidence interval 1.374-5.471).

CONCLUSIONS

CA-AKI occurred in one out of six ICU patients who underwent a contrast-enhanced radiography examination and was associated with both short-and long-term worse outcomes such as need for RRT, worse kidney function at discharge, increased length of stay in the ICU and hospital, and mortality.

Incidence, morbidity, and mortality of contrast-induced acute kidney injury in a surgical intensive care unit: a prospective cohort study

PURPOSE

Data on contrast-induced acute kidney injury (CI-AKI) in intensive care unit (ICU) are scarce and controversial. The objectives of the study were to evaluate the incidence and characteristics of CI-AKI in a surgical ICU.

MATERIALS AND METHODS

We conducted a 13-month prospective observational study. Three definitions were compared to characterize CI-AKI: Barrett and Parfrey criteria; Risk of renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function and End stage renal disease (RIFLE) classification; and Acute Kidney Injury Network (AKIN) criteria. Patients hospitalized in surgical ICU who had received an injection of contrast medium, who were not on renal replacement therapy, who had stable serum creatinine before injection, and no other etiology for new acute kidney injury were included.

RESULTS

One hundred one patients were included. The frequency of CI-AKI was 17%, 19%, and 19% according to Barrett and Parfrey criteria; RIFLE classification; and AKIN criteria, respectively. Diabetes mellitus, creatinine clearance less than 60 mL/min, and concomitant aminoglycoside administration were associated with CI-AKI. Statistically significant associations were found between CI-AKI and renal replacement therapy with all 3 definitions and between CI-AKI and mortality when AKIN criteria were used.

CONCLUSIONS

These results show that CI-AKI is not inconsequential in critically ill patients. In the present study, AKIN criteria appear to be most relevant to define CI-AKI. Further studies are required to explore CI-AKI prevention in ICU.

Efficacy of pentoxifylline in prevention of contrast-induced nephropathy in angioplasty patients

BACKGROUND

Contrast-induced nephropathy (CIN) is an adverse consequence of contrast media use that results in significant morbidity and mortality and adds significant costs to diagnostic and interventional cardiology procedures. Various pathophysiological mechanisms have been proposed for CIN and various agents have been tested for its prevention. There is currently a general agreement that adequate pre-procedure hydration constitutes the cornerstone of prevention, yet there are reports of the use of some other agents with various efficacies. We prospectively tested pentoxifylline (PTX), an antioxidant, anti-inflammatory drug, for CIN prevention in patients undergoing coronary angioplasty.

MATERIALS AND METHODS

In this prospective, randomized, single-blind, single-center clinical trial, 286 consecutive patients were randomly assigned to the control group (n = 146), with routine treatment and no PTX, or the study group (n = 140), with routine treatment and PTX, 400 mg/tid from 24 h before to 24 h after coronary angioplasty. Serum creatinine was measured before and 2 days after the procedure. The primary end point was the occurrence of CIN within 48 h.

RESULTS

The control and PTX groups were comparable in the overall predicted risk of CIN. Also, the type and volume of the contrast agent were not significantly different between the two groups. Following angioplasty, CIN occurred in 20 (13.69%) patients in the control group and in 12 (8.5%) patients in the study group; the difference was not statistically significant (P = 0.17). Additionally, there was no mortality and need for hemodialysis in either group.

CONCLUSION

In angioplasty patients, the prophylactic oral use of PTX could be recommended for CIN prevention, although no statistically significant protective effect was documented.

Contrast induced nephropathy: updated ESUR Contrast Media Safety Committee guidelines

PURPOSE

The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN).

AREAS COVERED

Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic measures used to reduce the incidence of CIN, and the management of patients receiving metformin. Key Points • Definition, risk factors and prevention of contrast medium induced nephropathy are reviewed. • CIN risk is lower with intravenous than intra-arterial iodinated contrast medium. • eGFR of 45 ml/min/1.73 m (2) is CIN risk threshold for intravenous contrast medium. • Hydration with either saline or sodium bicarbonate reduces CIN incidence. • Patients with eGFR ≥ 60 ml/min/1.73 m (2) receiving contrast medium can continue metformin normally.

Acute Kidney Injury Network definition of contrast-induced nephropathy in the critically ill: incidence and outcome

INTRODUCTION

Contrast-induced nephropathy (CIN) has been extensively studied in the ward but only scarcely in intensive care unit (ICU) patients, even if they may be particularly prone to develop or to worsen acute kidney insufficiency. We aimed to measure the incidence of CIN in a large ICU population using the Acute Kidney Injury Network (AKIN) definition and to investigate its impact on patients' outcome.

METHODS

In this 3-year retrospective study, we included all patients undergoing, during their stay in our medical ICU, a contrast media-enhanced computed tomographic scan. Change in serum creatinine between baseline (24 hours before to 12 hours after contrast media injection) and its maximum value over the 96 hours after contrast media injection was recorded. Contrast-induced nephropathy was defined as a 44.2-μmol/L absolute or a 25% relative minimal increase in serum creatinine over 48, 72, or 96 hours and according to the stage 1 of the AKIN classification (at least 26.4 μmol/L or 50% increase over 48 hours).

RESULTS

A total of 398 contrast-enhanced computed tomographic scans performed among 299 patients were analyzed. Incidence of CIN was 14% according to the AKIN definition and ranged from 8% (48-hour absolute definition) to 23% (96-hour relative definition). The need for renal replacement therapy and ICU mortality were significantly higher in case of CIN. After adjusting for other variables associated with ICU mortality, the occurrence of at least 1 CIN episode during the ICU stay (AKIN criteria) was independently associated with ICU mortality (odds ratio, 3.85; 95% confidence interval, 1.85-8.00).

CONCLUSIONS

Even if incidence varied greatly depending on the definition, CIN appeared frequent in our critically ill patients. The AKIN definition, independently associated with ICU mortality, may allow unifying diagnostic criteria to further evaluate this condition that impacts morbidity and mortality.

Early Diagnostic Markers for Contrast Nephropathy in Patients Undergoing Coronary Angiography

The present work aimed to prove the usage of neutrophil gelatinase-associated lipocalin (NGAL) as an early biomarker for kidney injury and to assess the relationship between NGAL and serum creatinine and cystatin C in patients with normal serum creatinine undergoing percutaneous coronary angiography. Thirty patients with normal serum creatinine undergoing coronary angiography were enrolled. Estimation of blood glucose, glycosylated hemoglobin, lipid profile, creatinine, NGAL, and cystatin C were done before coronary angiography for all patients. Serum creatinine, NGAL and cystatin C were evaluated again at 4 and 24 hours after coronary angiography. There was a significant increase in serum NGAL level 4 hours and 24 hours after coronary interventions compared to the baseline value before coronary angiography. Before coronary angiography, serum NGAL was positively correlated with serum creatinine, and cystatin C. Conclusion: Serum NGAL and cystatin C could be valuable in the detection of early renal impairment after coronary angiography.

N-acetylcysteine: short-term clinical benefits after coronary angiography in high-risk renal patients

INTRODUCTION AND OBJECTIVES

Previous studies on the role of N-acetylcysteine in the prevention of contrast-induced nephropathy after coronary angiography and on the drug's long-term effects have produced contradictory findings. The aim of this study was to clarify the benefits of N-acetylcysteine.

METHODS

A prospective, randomized, double-blind study was carried out in patients with chronic renal failure (plasma creatinine= >or=1.4 mg/dL) who underwent coronary angiography. This study concerns the second arm of the main study. Findings on the arm involving patients with normal renal function have been published previously. As before, patients were randomly assigned to receive either N-acetylcysteine, 600 mg every 12 h intravenously, or placebo. The primary end-point was the development of contrast-induced nephropathy.

RESULTS

The study included 81 patients (39 on N-acetylcysteine, 42 on placebo) with comparable baseline clinical characteristics. The overall incidence of contrast-induced nephropathy was 14.8% (12 patients): 5.1% (2 patients) in the N-acetylcysteine group and 23.8% (10 patients) in the placebo group (odds ratio [OR]=0.17; 95% confidence interval [CI], 0.03-0.84; P=.027). One patient (1.2%) in the latter group required dialysis while in the coronary unit. Multivariate analysis showed that N-acetylcysteine was an independent protective factor against the composite end-point of contrast-induced nephropathy, need for dialysis and mortality during the coronary unit stay (OR=0.20; 95% CI, 0.04-0.97; P=.04). Nevertheless, no significant difference was observed between the N-acetylcysteine and placebo groups in the rates of in-hospital (10.3% vs. 16.7%, respectively) or 1-year mortality (15.4% vs. 21.4%, respectively).

CONCLUSIONS

Prophylactic administration of N-acetylcysteine provided significant short-term clinical benefits in high-risk renal patients who underwent coronary angiography.

Prevention of acute kidney injury and protection of renal function in the intensive care unit. Expert opinion of the Working Group for Nephrology, ESICM

BACKGROUND

Acute renal failure on the intensive care unit is associated with significant mortality and morbidity.

OBJECTIVES

To determine recommendations for the prevention of acute kidney injury (AKI), focusing on the role of potential preventative maneuvers including volume expansion, diuretics, use of inotropes, vasopressors/vasodilators, hormonal interventions, nutrition, and extracorporeal techniques.

METHOD

A systematic search of the literature was performed for studies using these potential protective agents in adult patients at risk for acute renal failure/kidney injury between 1966 and 2009. The following clinical conditions were considered: major surgery, critical illness, sepsis, shock, and use of potentially nephrotoxic drugs and radiocontrast media. Where possible the following endpoints were extracted: creatinine clearance, glomerular filtration rate, increase in serum creatinine, urine output, and markers of tubular injury. Clinical endpoints included the need for renal replacement therapy, length of stay, and mortality. Studies are graded according to the international Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) group system.

CONCLUSIONS AND RECOMMENDATIONS

Several measures are recommended, though none carries grade 1A. We recommend prompt resuscitation of the circulation with special attention to providing adequate hydration whilst avoiding high-molecular-weight hydroxy-ethyl starch (HES) preparations, maintaining adequate blood pressure using vasopressors in vasodilatory shock. We suggest specific vasodilators [corrected] under strict hemodynamic control, sodium bicarbonate for emergency procedures administering contrast media, and periprocedural hemofiltration in severe chronic renal insufficiency undergoing coronary intervention.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s00134-009-1678-y) contains supplementary material, which is available to authorized users.

Risk of nephropathy is not increased by the administration of larger volume of contrast during coronary angiography

It is proposed that contrast-induced nephropathy (CN) correlates with the use of increasing contrast volumes during coronary angiography. This supposition has led to the current recommendation to limit the dose of contrast in patients at high risk for renal dysfunction. Limits in contrast dosing may negatively impact the evaluation of patients undergoing cardiac catheterization for myocardial infarction and acute coronary syndrome. The objective of this study was to empirically assess, in a large population, the presence and strength of this correlation. Baseline blood samples and clinical information were obtained from 5256 consenting patients hospitalized for coronary angiography. Levels of serum creatinine were measured pre- and postcatheterization, and the total change in serum creatinine was calculated. Nephropathy was defined as a change of > or =0.5 mg/dL. The total volume of contrast dye (iopamidol, nonionic) used during the angiography procedure was recorded. Logistic regression was used for the primary analysis.The average age was 64 +/- 14 years, and 67% of patients were male. Paradoxically, the incidence of CN was inversely related to the volume in the overall population: 16%, 14%, 8%, and 7% for quartile (Q) 1 (<115 mL), Q2 (115-160 mL), Q3 (161-225 mL), and Q4 (>225 mL) of contrast, respectively (P-trend <0.001). In multivariable regression, this trend toward lower CN remained (Q1 (referent) OR = 1.0, Q2: 1.02, Q3: 0.60, Q4: 0.53, P < 0.001). Other predictors included age, left ventricular ejection fraction, diabetes, and baseline creatinine level (all P < 0.001). For patients at high risk, with a baseline creatinine >2.0 mg/dL (n = 415), contrast volume (Q1: <75 mL, Q2: 75-120 mL, Q3: 121-170 mL, Q4: >170 mL) did not predict either increased or decreased risk of CN (48%, 42%, 49%, 43%, respectively, P-trend = 0.76). This lack of predictive value remained after multivariable adjustment.In this large population, no association was found between the amount of contrast used during angiography and the incidence of CN in patients at initial high risk. The apparent inverse relation of risk with volume in the overall population is likely explained by clinical practice bias. If confirmed, these results may have important clinical implications.

Contrast-induced nephropathy: pathogenesis and prevention

Contrast-induced nephropathy (CIN) is the third most common cause of acute kidney injury in hospitalized patients. Diagnostic and interventional cardiovascular procedures generate nearly half the cases. Elderly patients and those with chronic kidney disease, diabetes, and cardiovascular disease are at greatest risk. Procedure-related risk factors include large volumes of contrast and agents with a high osmolality. Renal medullary ischemia arising from an imbalance of local vasoconstrictive and vasodilatory influences coupled with increased demand for oxygen-driven sodium transport may be the key to its pathogenesis. Contrast agents may also have a direct cytotoxic effect that operates through the generation of reactive oxygen species. Pre- and post-procedure administration of normal saline, isotonic sodium bicarbonate, N-acetylcysteine, and a variety of other pharmacologic agents have been used to prevent or mitigate CIN. While normal saline is generally accepted as protective against CIN, uncertainty still surrounds the role of sodium bicarbonate and N-acetylcysteine. Dialytic therapies before, during, and after exposure to contrast have been tested with mixed results. Logistical and economic disincentives argue against these modalities.

Incidence of contrast-induced nephropathy in intensive care patients undergoing computerised tomography and prevalence of risk factors

Computerised tomography (CT) with contrast is frequently used in intensive care. Contrast-induced nephropathy (CIN) is an important complication largely studied in stable cardiology patients and can lead to acute renal failure. The aim of this study was to determine the incidence of CIN in an intensive care unit (ICU) setting and describe the prevalence of associated risk factors. We performed a retrospective analysis by review of electronic laboratory database and manual chart review of all patients in two tertiary intensive care units in Newcastle, New South Wales who underwent CT with intravenous contrast during their ICU stay in 2006. CIN was defined as an absolute increment in serum creatinine of 44.2 micromol/l or a relative increment of 25% from baseline at 48 to 72 hours following intravenous contrast. Patients' demographic, biochemical and contrast media data, physiological parameters, fluid and drug administrations and previously described as well as ICU specific risk factors were analysed. We compared CIN positive and CIN negative patients to identify risk factors associated with CIN. In total, 2043 patients were admitted to ICU during 2006 and 509 CT studies were performed. One hundred and forty-one of these included administration of intravenous contrast and 139 charts were reviewed. Sixteen out of 139 patients developed CIN (11.5%). More than 70% of patients had two or more risk factors. Age was the only risk factor found to be significantly associated with the development of CIN in a multivariate analysis (P value 0.04, OR 1.041, 95% confidence interval 1.002 to 1.081). Mortality was higher in CIN positive patients (31 vs 13%, P value 0.068). ICU and hospital length of stay was not significantly different in CIN positive and negative patients and persisting renal impairment was not found in CIN positive survivors. Based on this study, we cannot predict who will develop CIN in ICU using the described risk factors. Further prospective studies are needed to evaluate the incidence and outcomes of CIN in an ICU setting.

Mitigating contrast-induced acute kidney injury associated with cardiac catheterization

Contrast-induced nephropathy, also referred to as contrast-induced acute kidney injury (CIAKI), is among the most common causes of AKI, especially in patients with underlying chronic kidney disease. In addition to the increased cost engendered by the development of CIAKI, several studies have suggested the occurrence of AKI after cardiac procedures is associated with an increase in both morbidity and mortality. This increase in morbidity and mortality occurs after both intravenous and intra-arterial studies. This review focuses on relevant proposed pathophysiological mechanisms, risk factors, and current prophylactic strategies, which may reduce the incidence of CIAKI during cardiac angiographic imaging studies.

Prevention of contrast-induced nephropathy: an overview

Many unknowns remain concerning how best to reduce a patient's risk of contrast-induced nephropathy (CIN). Many interventions have been proposed, but few have gone unchallenged, and new questions have arisen from analysis of serum creatinine variations in patients who have not been exposed to radiographic iodinated contrast media (RICM). Use of alternate imaging tests that do not use RICM is the most direct way to avoid CIN. Hydration remains the bulwark of intervention when RICM must be administered. The administration of N-acetylcysteine is a popular pharmacologic prophylaxis against CIN but its efficacy is unclear. Hemodialysis has not been effective, but hemofiltration has shown good results in limited series.

N-acetylcysteine versus N-acetylcysteine + theophylline for the prevention of contrast nephropathy

BACKGROUND

The use of N-acetylcysteine or theophylline in specific subgroups of patients has been suggested to reduce the incidence of contrast-induced nephropathy (CIN) in patients undergoing angiographic procedures. Our purpose was to compare the use of N-acetylcysteine versus N-acetylcysteine + theophylline for the prevention of CIN.

MATERIALS AND METHODS

We randomized 217 patients with estimated glomerular filtration rate (eGFR) (calculated by Modification of Diet in Renal Disease formula) between 30 and 60 mL min(-1) 1.73 m(-2) who were undergoing coronary angiography to three prophylactic treatment groups: Group 1: Intravenous hydration with isotonic saline (1 mL kg(-1) h(-1) for 12 h before and after contrast, n = 72). Group 2: Intravenous hydration with isotonic saline (1 mL kg(-1) h(-1) for 12 h before and after contrast)+ N-acetylcysteine (600 mg p.o. twice daily the preceding day and the day of angiography, n = 73). Group 3: Intravenous hydration with isotonic saline (1 mL kg(-1) h(-1) for 12 h before and after contrast)+ N-acetylcysteine + theophylline (600 mg N-acetylcysteine p.o. and 200 mg theophylline p.o. twice daily for the preceding day and the day of angiography, n = 72). The incidence of CIN (0.5 mg dL(-1) increase in serum creatinine from the baseline value 48 h after intravascular injection of contrast) was compared in three groups.

RESULTS

Of the 217 patients, 12 patients (5.5%) experienced CIN. Five patients (6.9%) in group 1, seven patients (9.6%) in group 2 and zero (0%) patients in group 3 experienced CIN (P < 0.033).

CONCLUSION

Among patients with eGFR between 30 and 60 mL min(-1) 1.73 m(-2) undergoing coronary angiography, oral administration of N-acetylcysteine + theophylline in addition to saline hydration has a beneficial effect in the prevention of CIN.

[Contrast induced nephropathy]

Contrast media induced nephropathy is a common complication, particularly in high risk patients, such as patients with chronic kidney disease (CKD) and diabetes. The majority of studies show an increased in-hospital mortality and an unfavourable long-term prognosis after manifestation of contrast media induced nephropathy. The course and the potential risk factors of this type of acute renal failure are known. Therefore, an effective prophylaxis should allow to prevent this complication. In low risk patients oral or intravenous volume expansion is probably sufficient combined with the withdrawal of non-steroidal anti-inflammatory drugs. In high risk patients additional prophylactic measures are needed but their efficacy is not clearly defined. Therefore, heterogeneous recommendations exist. Hydration reduces (afferent) renovasoconstriction, the tubuloglomerular feedback, the tubulotoxic effects of contrast media (via dilution) and the oxygen radical formation. The optimal composition, timing and amount of fluid which should be administered to the patients remain unclear. Most studies show that intravenous administration of volume is more effective than oral fluid intake. The majority of studies found a benefit of isotonic sodium bicarbonate in comparison to isotonic saline solutions, even if meta-analyses displayed only a positive trend for sodium bicarbionate due to the heterogeneity of the data. Controversies exist for N-acetylcysteine, vitamin C, fenoldopam, theophylline or statins. Due to low cost and low side effects, N-Acetylcysteine is widely used. Theophyllin (given intravenously 30 minutes before contrast media injection) is renoprotective, particularly in intensive care unit patients. Very important is the reduction of contrast media volume (if possible <30 ml for diagnostic procedures and <100 ml for interventions). Iso-osmolar and low-osmolar contrast media may have a comparable low risk for the induction of contrast media induced nephropathy. This risk is probably higher after intra-arterial as compared to intravenous administration of contrast media. Controversies exist with respect to the reduction of contrast media induced nephropathy and mortality by prophylactic hemodialysis or hemofiltration. A possible benefit of these procedures consists probably for patients with advanced chronic kidney disease (stage 5). With the further increase of investigations using contrast media, with the further increase in vascular interventions, in age and comorbidities of the patients one may suggest that the problem of contrast media induced nephropathy will further increase, despite all prophylactic procedures so far recommended.

Role of probucol in preventing contrast-induced acute kidney injury after coronary interventional procedure

Enhanced production and reduced removal of oxygen free radicals may play an important role in the pathogenesis of the contrast-induced acute kidney injury (CIAKI). Probucol, a lipid-lowering drug with potent antioxidant properties, has been widely used clinically for the prevention of the progression of atherosclerosis. We performed a prospective, randomized controlled trial to investigate the role of probucol in the prevention of CIAKI in patients undergoing planned coronary angiography (CAG) or intervention. The 205 patients who underwent planned CAG or intervention were randomly assigned to either the probucol group (n = 102; 500 mg orally twice daily) or the control group (n = 103). Renal function was assessed at the time of hospital admission and on days 1, 2, and 3 after the procedure. CIAKI occurred in 23 (11.22%) of the 205 patients. The incidence of CIAKI in the probucol group was slightly lower compared with the control group (7.84% vs 14.56%) but without significant difference (p = 0.13). The postprocedure mean peak of serum creatinine (1.15 +/- 0.49 vs 1.33 +/- 0.78 mg/dl, p = 0.04) and the postprocedure increasing Scr from baseline (0.15 +/- 0.22 vs 0.25 +/- 0.21 mg/dl, p = 0.001) in the probucol group were significantly lower than those in the control group. In conclusion, prophylactic treatment with probucol during the periprocedural stage in patients undergoing coronary angiography or intervention has a preventive role against CIAKI.

[Iodinated contrast agent-induced nephropathy]

Contrast-induced nephropathy (CIN) is a well-known complication of therapeutic and diagnostic procedures requiring contrast administration and accounts for 10% of acute renal failure in hospitalized patients. Although the incidence of this complication is relatively low, its consequences can be catastrophic. The development of CIN is associated with increased length of hospital stay, an increased requirement for acute dialysis, and an increased risk of death. Preexisting renal dysfunction, age, diabetes, congestive heart failure, and volume of administered contrast are all associated with a risk of developing CIN. Despite a large number of clinical trials that have evaluated prophylaxis strategies for CIN, no uniform strategies have been developed so far. The use of N-acetyl-L-cysteine (NAC) or theophylline in specific subgroups of patients has been shown to reduce dialysis requirement and mortality in patients undergoing angiographic procedures. Hemofiltration has also shown positive results. In this review we will discuss the epidemiology and the risk factors for CIN and the evidence for commonly employed prophylaxis strategies, and we will provide general recommendations with respect to CIN prevention and management.A practicable strategy to prevent CIN includes: correct identification of individuals at greatest risk, thorough evaluation of whether other diagnostic maneuvers could be employed instead (i.e., sonography), application of low-osmolar contrast media at the minimum acceptable dose, stopping potential nephrotoxic drugs (NSAID), hydration with sodium chloride 0.9% 1 ml/kg per h i.v. 12 h before and after CM application, administration of acetylcysteine 600 mg twice the day before and after (in cases of emergency investigation and high-risk patients 1200 mg i.v.), and theophylline (250-350 mg) the day before and the day after CM application (in cases of emergency investigation 5 mg/kg i.v.).