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

[Cancer imaging and prevention of renal failure]

The risk of acute renal failure (ARF) following iodinated contrast media injection has long been overestimated because of the previous use of more toxic ICPs and uncontrolled studies. Nowadays, this concept is being questioned. Patients with severe renal failure and/or ARF are the only group still considered at risk. In these patients, it is necessary to discuss an alternative without an iodinated contrast agent. Contrast-enhanced ultrasound, MRI, spectral CT or PET-CT scan can be used instead of contrast-enhanced CT. Preventive measures should be applied when appropriate substitute to CT is not available or not diagnosed (minimum necessary dose of ICP, interruption of some treatments and prior hydration). These recommendations formalized by the European Society of Urogenital Radiology (ESUR) in 2018 address most situations faced by clinicians. In complex situations, an opinion from a nephrologist remains necessary after asking the radiologist about the availability of acceptable substitutes.

Prospective Randomized Trial of Na/K Citrate for the Prevention of Contrast-Induced Nephropathy in High-risk Patients

Background

Contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI) refers to an acute kidney injury (AKI) occurring after exposure to contrast media, commonly used in diagnostic procedures or therapeutic angiographic interventions. Recently, Na/K citrate, used for urine alkalinization, has been assessed for preventing CIN. This experiment evaluated Na/K citrate's efficacy in preventing CIN in high-risk patients undergoing cardiac catheterization.

Methods

A prospective randomized clinical trial involved 400 patients with moderate- to high-risk factors for CIN undergoing elective percutaneous coronary intervention (PCI). They were randomly assigned to either the control or Na/K citrate groups. The Na/K citrate group (n = 200) received a 5 g Na/K citrate solution diluted in 200 mL water 2 hours before and 4 hours after the first administration, along with intravenous hydration for 2 hours before and 6 hours after the procedure. In contrast, the control group (n = 200) received only intravenous hydration. Serum creatinine (SCr) levels were measured before contrast exposure and 48 hours afterward. CIN was defined as a 25% increase in serum creatinine (SCr) or > 0.5 mg/dL 48 hours after contrast administration. The significance level was set at P ˂ 0.05.

Results

CIN was observed in 33 patients (16.5%) in the control group and 6 patients (3%) in the Na/K citrate group. The incidence of CIN was found to have a significant difference between the 2 groups 48 hours after receiving the radiocontrast agent (P < 0.001).

Conclusion

Our results show that Na/K citrate is helpful and substantially reduces the incidence of CIN.

Preventing post-contrast acute kidney injury and hypersensitivity reactions: UK national audit

AIM

To audit UK radiology departmental protocols related to the prevention of Iodine-based contrast media (ICM) adverse drug reactions (ADRs) and to assess their compliance with the Royal College of Radiologists (RCR) endorsed Royal Australian and New Zealand College of Radiologists' 2018 Iodinated Contrast Guidelines.

MATERIALS AND METHODS

Questionnaires were sent to all UK acute National Health Service (NHS) providers treating adult patients with an audit lead registered with the RCR (162 providers encompassing 211 hospital radiology departments). The questionnaire included three main sections: renal function screening, renal protection regimens, and hypersensitivity reactions prevention and follow-up. Data collection was conducted between April and July 2022.

RESULTS

Sixty-one per cent (129/211) of departments responded, representing 67% of eligible providers. An independent imaging services provider supplied one additional set of data (n=130 overall). Of the responding departments, for post-contrast acute kidney injury (PC-AKI), 41% and 56% had the recommended risk assessment for inpatients and outpatients, respectively. Renal function testing was often over-utilised, and their results were applied improperly. Sixty-eight per cent of departments used the advised threshold for considering renal protection. For hypersensitivity reactions, 9% of departments had the correct risk assessment. Thirty-six per cent of departments had the correct risk mitigation protocol for identified high-risk patients. The documentation and follow-up for hypersensitivity reactions were similarly inadequate.

CONCLUSION

Local protocols on preventing ICM ADRs were largely non-compliant with RCR guidelines. Departments need to update their protocols in line with current evidence to avoid iatrogenic morbidity or unnecessary tests and over-precaution.

Hydration to Prevent Contrast-Associated Acute Kidney Injury in Patients Undergoing Cardiac Angiography

Administration of fluid (oral and intravenous) is the cornerstone of prevention of contrast-associated acute kidney injury in the cardiac environment. Intravenous saline is the preferred fluid. The amount, timing, and duration of therapy are discussed. A key determinant of the benefit may be the rate of urine output stimulated by the therapy. Approaches using hemodynamic-guided rates of fluid administration and novel techniques to generate large urine outputs while maintaining fluid balance are highlighted.

Acute Kidney Injury Management Strategies Peri-Cardiovascular Interventions

In many countries, the aging population and the higher incidence of comorbid conditions have resulted in an ever-growing need for cardiac interventions. Acute kidney injury (AKI) is a common complication of these interventions, associated with higher mortalities, chronic or end-stage kidney disease, readmission rates, and hospital and post-discharge costs. The AKI pathophysiology includes contrast-associated AKI, hemodynamic changes, cardiorenal syndrome, and atheroembolism. Preventive measures include limiting contrast media dose, optimizing hemodynamic conditions, and limiting exposure to other nephrotoxins. This review article outlines the current state-of-art knowledge regarding AKI pathophysiology, risk factors, preventive measures, and management strategies in the peri-interventional period.

Intravenous versus oral hydration to reduce the risk of postcontrast acute kidney injury after intravenous contrast-enhanced CT in patients with severe chronic kidney disease (ENRICH): a study protocol for a single-centre, parallel-group, open-labelled non-inferiority randomised controlled trial in Denmark

INTRODUCTION

Contrast-enhanced CT (CECT) is widely used for diagnostic purposes. The use of contrast medium carries a risk for postcontrast acute kidney injury (PC-AKI), especially in patients with AKI or chronic kidney disease (CKD). Current guidelines recommend prophylactic intravenous hydration to prevent PC-AKI in high-risk patients. Oral hydration is non-inferior to intravenous hydration in patients with moderate CKD, but it has not been evaluated in high-risk patients.

METHODS AND ANALYSIS

The ENRICH trial will enrol 254 patients with estimated glomerular filtration rate ≤30 mL/min/1.73 m2 undergoing intravenous CECT, who are block randomised (2-4-2) with stratification for CKD stage, diabetes status, and indication for referral to prophylactic treatment with oral or intravenous hydration. PC-AKI is defined as an absolute increase in SCr of >0.3 mg/dL or >1.5 from baseline at 2-5 days. Renal function will also be evaluated <90 days, <7 days and 1-3 days before intravenous CECT, and 25-40 days after intravenous CECT. Secondary outcomes include dialysis, renal adverse events, hospitalisation due to hydration-related or contrast-related sequelae, and all-cause mortality ≤30 days postcontrast. Pre- and postcontrast plasma and urinary biomarkers will be evaluated for diagnostic and prognostic accuracy of the primary and secondary outcomes.

ETHICS AND DISSEMINATION

Oral hydration is patient-friendly and less costly compared with intravenous hydration. If oral hydration is non-inferior to intravenous hydration in high-risk patients, it could be implemented as new hydration strategy, which will facilitate the clinical diagnosing of elective patients with severe CKD without unnecessary resource utilisation. The protocol is approved by the Regional Scientific Ethical Committee for Southern Denmark (S-20210126), and the Data Protection Agency (21/66779). The study is conducted in accordance with the Declaration of Helsinki. Positive as well as negative findings will be reported in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05283512.

Oral Sodium Chloride in the Prevention of Contrast-Associated Acute Kidney Injury in Elderly Outpatients: The PNIC-Na Randomized Non-Inferiority Trial

OBJECTIVE

We aimed to test the non-inferiority of oral versus intravenous hydration in the incidence of contrast-associated acute kidney injury (CA-AKI) in elderly outpatients undergoing a contrast-enhanced computed tomography (CE-CT) scan.

METHODS

PNIC-Na (NCT03476460) is a phase-2, single-center, randomized, open-label, non-inferiority trial. We included outpatients undergoing a CE-CT scan, >65 years having at least one risk factor for CA-AKI, such as diabetes, heart failure, or an estimated glomerular filtration rate (eGFR) of 30-59 mL/min/1.73 m². Participants were randomized (1:1) to oral sodium-chloride capsules or intravenous hydration. The primary outcome was an increase in serum creatinine >0.3 mg/dL or a reduction in eGFR >25% within 48 h. The non-inferiority margin was set at 5%.

RESULTS

A total of 271 subjects (mean age 74 years, 66% male) were randomized, and 252 were considered for the main analysis (per-protocol). A total of 123 received oral hydration and 129 intravenous. CA-AKI occurred in 9 (3.6%) of 252 patients and 5/123 (4.1%) in the oral-hydration group vs. 4/129 (3.1%) in the intravenous-hydration group. The absolute difference between the groups was 1.0% (95% CI -4.8% to 7.0%), and the upper limit of the 95% CI exceeded the pre-established non-inferiority margin. No major safety concerns were observed.

CONCLUSION

The incidence of CA-AKI was lower than expected. Although both regimens showed similar incidences of CA-AKI, the non-inferiority was not shown.

Fluid administration strategies for the prevention of contrast-associated acute kidney injury

PURPOSE OF REVIEW

The known timing of contrast media exposure in patients identified as high-risk for contrast-associated acute kidney injury (CA-AKI) enables the use of strategies to prevent this complication of intravascular contrast media exposure. Although multiple preventive strategies have been proposed, periprocedural fluid administration remains as the primary preventive strategy. This is a critical review of the current evidence evaluating a variety of fluid administration strategies in CA-AKI.

RECENT FINDINGS

Fluid administration strategies to prevent CA-AKI include comparisons of intravenous (i.v.) to no fluid administration, different fluid solutions, duration of fluid administration, oral hydration, left ventricular end diastolic-pressure guided fluid administration and forced diuresis techniques.

SUMMARY

Despite an abundance of fluid administration trials, it is difficult to make definitive recommendations about preventive fluid administration strategies due to low scientific quality of published studies. The literature supports use of i.v. compared with no fluid administration, especially in high-risk patients undergoing intra-arterial contrast media exposure. Use of isotonic saline is recommended over 0.45% saline or isotonic sodium bicarbonate. Logistical considerations support shortened over longer i.v. fluid administration strategies, despite an absence of evidence of equivalent efficacy. Current literature does not support oral hydration for high-risk patients. The use of tailored fluid administration in heart failure patients and forced diuresis with matching fluid administration are promising new fluid administration strategies.

Oral hydration compared to intravenous hydration in the prevention of post-contrast acute kidney injury in patients with chronic kidney disease stage IIIb: A phase III non-inferiority study (NICIR study)

OBJECTIVE

To evaluate the non-inferiority of oral hydration compared to intravenous (i.v.) hydration in the prevention of post-contrast acute kidney injury (PC-AKI) in patients with stage IIIb chronic kidney disease (CKD) referred for an elective contrast-enhanced computed tomography (CE-CT).

MATERIAL AND METHODS

This is a prospective, randomized, phase 3, parallel-group, open-label, non-inferiority trial. Patients were randomly assigned 1:1 to receive prophylaxis against PC-AKI either with oral hydration: 500 mL of water two hours before and 2000 mL during the 24 h after performing CE-CT or i.v. hydration: sodium bicarbonate (166 mmol/L) 3 mL/kg/h starting one hour before and sodium bicarbonate (166 mmol/L) 1 mL/kg/h during the first hour after CE-CT. 100 mL of non-ionic iodinated contrast was administered in all cases. The primary outcome was the proportion of PC-AKI in the first 48-72 h after CE-CT. Secondary outcomes were persistent PC-AKI, the need for hemodialysis, and the occurrence of adverse events related to prophylaxis.

RESULTS

Of 264 patients randomized between January 2018 and January 2019, 114 received oral hydration, and 114 received i.v. hydration and were evaluable. No significant differences were found (p > 0.05) between arms in clinical characteristics or risk factors. PC-AKI rate was 4.4 % (95 %CI: 1.4-9.9 %) in the oral hydration arm and 5.3 % (95 %CI: 2.0-11.1%) in the i.v. hydration arm. The persistent PC-AKI rate was 1.8 % (95 %CI: 0.2-6.2 %) in both arms. No patient required dialysis during the first month after CE-CT or had adverse effects related to the hydration regime.

CONCLUSION

In those with stage IIIb CKD referred for an elective CE-CT, we provide evidence of non-inferiority of oral hydration compared to i.v. hydration in the prevention of PC-AKI.

Contrast-associated acute kidney injury: An update of risk factors, risk factor scores, and preventive measures

As lifespans lengthen, age-related diseases such as cardiovascular disease and diabetes are becoming more prevalent. Correspondingly, the use of contrast agents for medical imaging is also becoming more common, and there is increasing awareness of contrast-associated acute kidney injury (CA-AKI). There is no specific treatment for CA-AKI, and clinicians currently focus on prevention, interventions that alter its pathogenesis, and identification of risk factors. Although the incidence of CA-AKI is low in the general population, the risk of CA-AKI can reach 20% to 30% in patients with multiple risk factors. Many models have been applied in the clinic to assess the risk factors for CA-AKI, enable identification of high-risk groups, and improve clinical management. Hypotonic or isotonic contrast media are recommended to prevent CA-AKI in high-risk patients. Patients with risk factors should avoid using contrast media multiple times within a short period of time. All nephrotoxic drugs should be stopped at least 24 h before the administration of contrast media in high-risk populations, and adequate hydration is recommended for all patients. This review summarizes the pathophysiology of CA-AKI and the progress in diagnosis and differential diagnosis; updates the risk factors and risk factor scoring systems; reviews the latest advances related to prevention and treatment; discusses current problems in epidemiological studies; and highlights the importance of identifying high-risk subjects to control modifiable risk factors and use of a rating scale to estimate the risk and implement appropriate prevention strategies.

Contrast-induced acute kidney injury in acute ischaemic stroke patients

PURPOSE

The potential nephrotoxicity of intravenous iodinated contrast media is a major concern for acute ischaemic stroke imaging evaluation. This study aimed to assess the incidence of acute kidney injury after intravenous iodinated contrast media exposure in acute ischaemic stroke patients.

METHODS

We conducted a retrospective cohort analysis between January 2012 and July 2018 to select adult patients admitted to the emergency department with acute ischaemic stroke. The exposed patients received a uniform intravenous dose of low osmolar non-ionic iodinated contrast media, as part of the imaging protocol for acute ischaemic stroke. The unexposed patients underwent a non-enhanced cranial computed tomography scan. Acute kidney injury was defined according to the Kidney Disease Improving Global Outcomes criteria, limited to the first 72 hours.

RESULTS

A total of 161 and 105 patients were included in the exposed and unexposed groups, respectively. The median age was 72.8 years (interquartile range 20), 53% were men and 97% were white. Demographic and baseline characteristics were similar between the groups. The incidence of acute kidney injury between exposed (n = 10, 6.2%) and unexposed (n = 1, 1%) groups (P = 0.073) was similar and contrast exposure was not a significant predictor of acute kidney injury.

CONCLUSION

Intravenous iodinated contrast media exposure during acute ischaemic stroke imaging protocols is not an independent predictor of acute kidney injury in patients with normal or near-normal renal function. Studies with larger sample sizes would help to clarify if patients with both cardiovascular risk factors and impaired renal function could benefit from prophylactic measures.

Safety of a rapid outpatient hydration protocol for patients with renal impairment requiring intravenous iodinated contrast media for CT

INTRODUCTION

Patients receiving intravenous iodinated contrast media (IOCM) for CT are predisposed to contrast-induced nephropathy. Chronic kidney disease is an important risk factor, and hydration is the mainstay of prevention. While inpatients can undergo intravenous hydration, there is a knowledge deficit regarding regimens for outpatients. We employed a rapid outpatient hydration protocol to reduce postponement of scan appointments for patients with suboptimal estimated glomerular filtration rate (eGFR).

METHODS

From June 2015, we amended our CT preparation protocol to mandate rapid hydration (oral, intravenous or both) for patients with an eGFR of 30-60 mL/min/1.73 m2. Patients receiving this hydration protocol from June to November 2015 were followed up for one month to monitor any admissions for fluid overload, and up to one year to determine the long-term effect on eGFR.

RESULTS

226 outpatients received the hydration protocol, which correlated with a 95% reduction in postponement of imaging appointments. No complications of fluid overload from hydration were encountered. There was a significant association between age and decrease in eGFR, but this was not significant when stratified by drop in eGFR category. No statistical significance was found between decrease in eGFR and gender or race. Higher baseline eGFR was less likely to be associated with decrease in eGFR after imaging. Type of hydration was not related to a drop in eGFR category for patients with eGFR of 45-59 mL/min/1.73 m2.

CONCLUSION

We defined a shorter hydration regimen that is safe to use in the outpatient setting.

Diagnostics, Risk Factors, Treatment and Outcomes of Acute Kidney Injury in a New Paradigm

Acute kidney injury (AKI) is a common clinical condition among patients admitted in the hospitals. The condition is associated with both increased short-term and long-term mortality. With the development of a standardized definition for AKI and the acknowledgment of the impact of AKI on patient outcomes, there has been increased recognition of AKI. Two advances from past decades, the usage of computer decision support and the discovery of AKI biomarkers, have the ability to advance the diagnostic method to and further management of AKI. The increasingly widespread use of electronic health records across hospitals has substantially increased the amount of data available to investigators and has shown promise in advancing AKI research. In addition, progress in the finding and validation of different forms of biomarkers of AKI within diversified clinical environments and has provided information and insight on testing, etiology and further prognosis of AKI, leading to future of precision and personalized approach to AKI management. In this this article, we discussed the changing paradigms in AKI: from mechanisms to diagnostics, risk factors, and management of AKI.

Use of Intravenous Iodinated Contrast Media in Patients with Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation

Intravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Although the true risk of CI-AKI remains uncertain for patients with severe kidney disease, prophylaxis with intravenous normal saline is indicated for patients who have AKI or an estimated glomerular filtration rate less than 30 mL/min/1.73 m² who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an estimated glomerular filtration rate of 30-44 mL/min/1.73 m² at the discretion of the ordering clinician. This article is a simultaneous joint publication in Radiology and Kidney Medicine. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article.

Use of Intravenous Iodinated Contrast Media in Patients With Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation

Intravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Although the true risk of CI-AKI remains uncertain for patients with severe kidney disease, prophylaxis with intravenous normal saline is indicated for patients who have AKI or an estimated glomerular filtration rate less than 30 mL/min/1.73 m² who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an estimated glomerular filtration rate of 30-44 mL/min/1.73 m² at the discretion of the ordering clinician.

The association between post-procedural oral hydration and risk of contrast-induced acute kidney injury among ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention

BACKGROUND

Oral hydration with water may be inexpensive and effective in the prevention of contrast-induced acute kidney injury (CI-AKI), but its efficacy among ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI) remains unknown.

METHODS

This was a prospective, single-center, observational study. We consecutively enrolled 308 STEMI patients undergoing primary PCI. All patients drank unrestricted amounts of fluids freely, whose volume was recorded until 24 hours following primary PCI. Oral hydration volume/weight ratios (OHV/W) were calculated. Adequate oral hydration was defined as a ratio over 12 mL/kg within 24 hours after primary PCI. The primary outcome measure was CI-AKI, defined as a 25% or 0.5 mg/dL increase in serum creatinine from baseline during the first 48-72 hours post-procedure. The association between adequate post-procedural oral hydration and CI-AKI was assessed using multivariable logistic analysis.

RESULTS

Post-procedural prophylactic oral hydration was implemented in 90.91% (280/308) of STEMI patients undergoing primary PCI. There were no differences in the sex, age, weight, index blood pressure, LVEF, anemia, diabetes mellitus, contrast volume used during the coronary procedures between groups (P>0.05). The incidence of CI-AKI was much higher in the inadequate oral hydration group (<12 mL/kg) than the adequate group (≥12 mL/kg) (53.57% vs. 21.79%, P=0.0002). Multivariate logistic regression showed adequate oral hydration (≥12 mL/kg) was the independent protective factor associated with CI-AKI (OR =0.349, 95% CI: 0.147-0.828, P=0.0170), after adjusting confounders, including age, female gender, baseline serum creatinine, diabetes mellitus, use of diuretics, congestive heart failure and intravenous hydration volume.

CONCLUSIONS

Our study determined the association of post-procedural adequate oral hydration on CI-AKI following primary PCI, which was a potential strategy for CI-AKI prevention among patients with STEMI at very high risk.

Efficacy of post-procedural oral hydration volume on risk of contrast-induced acute kidney injury following primary percutaneous coronary intervention: study protocol for a randomized controlled trial

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) contributes toward unfavorable clinical outcomes. Oral hydration with water is inexpensive and it may be effective in the prevention of CI-AKI, but its efficacy among patients undergoing primary percutaneous coronary intervention (PCI) remains unknown.

METHODS/DESIGN

Our study is a secondary analysis on the database from the ATTEMPT study. We enrolled ST-elevation myocardial infarction (STEMI) patients undergoing primary PCI. Eligible patients received peri-procedural aggressive (left ventricular end-diastolic pressure-guided) or routine (≤ 500 mL) intravenous hydration with an isotonic solution (0.9% NaCl) with randomization. The primary endpoint was CI-AKI, defined as a > 25% or 0.5 mg/dL increase in serum creatinine from baseline during the first 48-72 h post-procedurally. All patients drank unrestricted amounts of fluids freely, the volume of which was recorded until 24 h following primary PCI. Oral hydration volume/weight (OHV/W) ratios were calculated. The association between post-procedural oral hydration (quartiles) and CI-AKI was assessed using multivariable analysis controlling for confounders, including intravenous hydration strategies.

DISCUSSION

Our study determined the effects of post-procedural oral hydration on CI-AKI following primary PCI, which is a potential strategy for CI-AKI prevention among patients with STEMI at very high risk.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02067195 . Registered on 21 February 2014.

Safety and Efficacy of Tolvaptan for the Prevention of Contrast-Induced Acute Kidney Injury in Patients with Heart Failure and Chronic Kidney Disease

Background

Tolvaptan is a promising drug for the prevention of contrast-induced acute kidney injury (CI-AKI) because it induces aquaresis without adversely affecting renal hemodynamics. CI-AKI is a major cause of acute renal failure associated with increased morbidity and mortality.

Objective

To investigate the effectiveness of different doses of tolvaptan for the prevention of CI-AKI.

Method

Ninety-one consecutive patients with congestive heart failure (CHF) and chronic kidney disease (CKD) were prospectively enrolled as the tolvaptan group in this study (T-group; 7.5-mg: n = 42, 15-mg: n = 49). In addition, 91 consecutive patients with CHF and CKD were collected retrospectively as a control group (C-group, n = 91). All patients received continuous intravenous infusion of isotonic saline, and tolvaptan was administered to the T-group.

Results

One patient developed CI-AKI in the T-group versus 3 in the C-group (1.1 vs. 3.3%, p = 0.61). On the other hand, the change of serum creatinine in the T-group was lower than that in the C-group. Additionally, in the 7.5-mg group, serum creatinine was unchanged up to 72 h after contrast administration, showing a significant difference from the 15-mg group (-0.00 ± 0.09 vs. 0.05 ± 0.12 mg/dL, p = 0.009). Similarly, the change of eGFR was significantly smaller in the 7.5-mg group than that in the 15-mg group (0.7 ± 5.4 vs. -2.8 ± 5.1 mL/min/1.73 m², p = 0.002). No patient required hemodialysis and there was no prolongation of hospitalization due to exacerbation of heart failure.

Conclusions

Compared to hydration alone, tolvaptan combined with hydration could be a safer method for preventing CI-AKI while avoiding exacerbation of heart failure, and a dosage of 7.5-mg might be safer than 15-mg.

Is the risk of contrast-induced nephropathy a real contraindication to perform intravenous contrast enhanced Computed Tomography for non-traumatic acute abdomen in Emergency Surgery Department?

BACKGROUND

Contrast enhanced Computed Tomography (CCT) is the most used imaging test to investigate acute abdominal clinical conditions, because of its high sensitivity and specificity. It is mandatory to make a correct and prompt diagnosis when life threatening abdominal diseases as mesenteric ischemia are suspected. Contrast medium administration was linked to acute renal failure, therefore radiologist often prefer to perform CCT without contrast in patients needing to undergo the exam with increased serum creatinine.  The aim of the review was to focus on the incidence of contrast induced nephropathy in patients presenting non-traumatic acute abdominal clinical conditions, who underwent CCT with intravenous contrast agent administration in emergency setting.

MATERIALS AND METHODS

The systematic review protocol was guided by the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocol (PRISMA-P). Quality of the evidence will be evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

RESULTS

The strongest currently available evidence on the incidence of post-contrast acute kidney injury (AKI) following intravenous contrast agent administration consists in a meta-analysis of observational studies. Data extracted from meta-analyses demonstrate that, compared with non-contrast CT, CCT was not significantly associated with AKI. Moreover, the risk of AKI (RR=0.79; 95% confidence interval [CI]: 0.62, 1.02; P=.07), death (RR=0.95; 95% CI: 0.55, 1.67; P=.87), and dialysis (RR=0.88; 95% CI: 0.23, 3.43; P=.85) is similar, compared with the risk of AKI in the non-contrast medium group. Furthermore, intravenous low-osmolality iodinated contrast material is a nephrotoxic risk factor, but not in patients with a stable SCr level less than 1.5 mg/dL, therefore many factors other than contrast material could affect PC-AKI rates.

DISCUSSION AND CONCLUSIONS

The benefits of diagnostic information gained from contrast enhanced TC in assessing AA are fundamental in some clinical scenarios. The risk of contrast induced nephropathy (CIN) is negligible in patients with normal renal function but the incidence appears to rise to as high as 25% in patients with pre-existing renal impairment or in the presence of risk factors such as diabetes, advanced age, vascular disease and use of certain concurrent medications. The incidence of CIN/AKI after intravenous contrast administration is very low in general population. Radiologists and referring physicians should be familiar with the risk factors for renal disease, CIN and preventing measures.

Emergency Department Use of Contrast Computed Tomography in Patients With Renal Dysfunction

The Research to Practice Column is designed to improve translational research critique skills of advanced practice nurses. In this issue, the article "Risk of Acute Kidney Injury After Intravenous Contrast Media Administration" () is discussed in the context of a patient presenting to the emergency department with acute abdominal pain. The study was designed to assess the risk of acute kidney injury and adverse clinical outcomes in patients receiving intravenous contrast for computed tomography. Advanced practice nurses need to be aware of advances in types of intravenous contrast and current recommendations for administration of intravenous contrast for diagnostic purposes in patients at risk for acute kidney injury to facilitate making timely and accurate diagnoses.

Post-contrast acute kidney injury. Part 2: risk stratification, role of hydration and other prophylactic measures, patients taking metformin and chronic dialysis patients : Recommendations for updated ESUR Contrast Medium Safety Committee guidelines

OBJECTIVES

The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 2011 guidelines on the prevention of post-contrast acute kidney injury (PC-AKI). The results of the literature review and the recommendations based on it, which were used to prepare the new guidelines, are presented in two papers. AREAS COVERED IN PART 2: Topics reviewed include stratification of PC-AKI risk, the need to withdraw nephrotoxic medication, PC-AKI prophylaxis with hydration or drugs, the use of metformin in diabetic patients receiving contrast medium and the need to alter dialysis schedules in patients receiving contrast medium.

KEY POINTS

• In CKD, hydration reduces the PC-AKI risk • Intravenous normal saline and intravenous sodium bicarbonate provide equally effective prophylaxis • No drugs have been consistently shown to reduce the risk of PC-AKI • Stop metformin from the time of contrast medium administration if eGFR < 30 ml/min/1.73 m 2 • Dialysis schedules need not change when intravascular contrast medium is given.

Effectiveness of oral hydration in preventing contrast-induced acute kidney injury in patients undergoing coronary angiography or intervention: a pairwise and network meta-analysis

BACKGROUND

The effectiveness of oral hydration in preventing contrast-induced acute kidney injury (CI-AKI) in patients undergoing coronary angiography or intervention has not been well established. This study aims to evaluate the efficacy of oral hydration compared with intravenous hydration and other frequently used hydration strategies.

METHODS

PubMed, Embase, Web of Science, and the Cochrane central register of controlled trials were searched from inception to 8 October 2017. To be eligible for analysis, studies had to evaluate the relative efficacy of different prophylactic hydration strategies. We selected and assessed the studies that fulfilled the inclusion criteria and carried out a pairwise and network meta-analysis using RevMan5.2 and Aggregate Data Drug Information System 1.16.8 software.

RESULTS

A total of four studies (538 participants) were included in our pairwise meta-analysis and 1754 participants from eight studies with four frequently used hydration strategies were included in a network meta-analysis. Pairwise meta-analysis indicated that oral hydration was as effective as intravenous hydration for the prevention of CI-AKI (5.88 vs. 8.43%; odds ratio: 0.73; 95% confidence interval: 0.36-1.47; P>0.05), with no significant heterogeneity between studies. Network meta-analysis showed that there was no significant difference in the prevention of CI-AKI. However, the rank probability plot suggested that oral plus intravenous hydration had a higher probability (51%) of being the best strategy, followed by diuretic plus intravenous hydration (39%) and oral hydration alone (10%). Intravenous hydration alone was the strategy with the highest probability (70%) of being the worst hydration strategy.

CONCLUSION

Our study shows that oral hydration is not inferior to intravenous hydration for the prevention of CI-AKI in patients with normal or mild-to-moderate renal dysfunction undergoing coronary angiography or intervention.

Allopurinol prophylactic therapy and the prevention of contrast-induced nephropathy in high-risk patients undergoing coronary angiography: A prospective randomized controlled trial

BACKGROUND

Contrast-induced nephropathy (CIN) is considered to be a possibly severe complication of radiography and thus, remains to be the main cause of acute kidney injury (AKI) for inpatients. A clinical trial was executed to measure the preventive effect of allopurinol against CIN in high-risk patients undertaking coronary angiography.

METHODS

Through randomized controlled trial, 140 patients with at minimum two risk factors of CIN, undertaking coronary angiography, were randomly allocated to the allopurinol (n = 70) or control group (n = 70). Those in the allopurinol group received allopurinol (300 mg) a day before their coronary angiography and intravenous hydration for 12 hours before and after their procedure, while members of the control group only received intravenous hydration. Serum creatinine (SCr), blood urea nitrogen (BUN) and uric acid were measured before and 48 hours after the procedure. CIN was defined by a 25% increase in SCr or the concentration of > 0.5 mg/dl, 48 hours after coronary angiography.

RESULTS

CIN was observed in 8 (11.4%) patients in the allopurinol group and 11 (15.7%) patients in the control group. There was no significant difference in the incidence of CIN between the two groups at 48 hours after coronary angiography (P = 0.459). In the allopurinol group, the median SCr concentration decreased non-significantly from 1.16 mg/dl to 1.13 mg/dl, 48 hours after coronary angiography (P = 0.189). In the control group, the median SCr concentration increased significantly from 1.11 mg/dl to 1.2 mg/dl, 48 hours after coronary angiography (P < 0.001).

CONCLUSION

Allopurinol presents no considerable effectiveness over the hydration protocol for development of CIN in high-risk patients.

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.

Reducing Acute Kidney Injury Due to Contrast Material: How Nurses Can Improve Patient Safety

BACKGROUND

Acute kidney injury due to contrast material occurs in 3% to 15% of the 2 million cardiac catheterizations done in the United States each year.

OBJECTIVE

To reduce acute kidney injury due to contrast material after cardiovascular interventional procedures.

METHODS

Nurse leaders in the Northern New England Cardiovascular Disease Study Group, a 10-center quality improvement consortium in Maine, New Hampshire, and Vermont, formed a nursing task force to reduce acute kidney injury due to contrast material after cardiovascular interventional procedures. Data were prospectively collected January 1, 2007, through June 30, 2012, on consecutive nonemergent patients (n = 20 147) undergoing percutaneous coronary interventions.

RESULTS

Compared with baseline rates, adjusted rates of acute kidney injury among the 10 centers were significantly reduced by 21% and by 28% in patients with baseline estimated glomerular filtration rate less than 60 mL/min per 1.73 m2. Key qualitative system factors associated with improvement included use of multidisciplinary teams, standardized fluid orders, use of an intravenous fluid bolus, patient education about oral hydration, and limiting the volume of contrast material.

CONCLUSIONS

Standardization of evidence-based best practices in nursing care may reduce the incidence of acute kidney injury due to contrast material.

The effects of contrast media volume on acute kidney injury after transcatheter aortic valve replacement: a systematic review and meta-analysis

OBJECTIVE

The goal of this systematic review was to assess the effects of contrast media volume on transcatheter aortic valve replacement-related acute kidney injury.

METHODS

A literature search was performed using Medline, EMbase, the Cochrane Database of Systematic Reviews, and clinicaltrials.gov from the inception of these databases through December 2015. Studies that reported relative risk, odds ratio, or hazard ratio comparing the risks of acute kidney injury following transcatheter aortic valve replacement in patients who received high contrast media volume were included. Pooled risk ratio (RR) and 95% confidence intervals (95% CI) were calculated using a random-effect, generic inverse variance method.

RESULTS

Four cohort studies composed of 891 patients were included in the analyses to assess the risk of acute kidney injury after transcatheter aortic valve replacement in patients who received high contrast media volume. The pooled RR of acute kidney injury after transcatheter aortic valve replacement in patients who received a large volume of contrast media was 1.41 (95% CI, 0.87 to 2.28) compared with low contrast media volume. The meta-analysis was limited to studies using standard acute kidney injury definitions, and the pooled RR of acute kidney injury in patients who received high contrast media volume is 1.12 (95% CI, 0.78 to 1.62).

CONCLUSION

Our meta-analysis shows no significant association between contrast media volume and risk of acute kidney injury after transcatheter aortic valve replacement.

Ultralow Iodine Dose Transarterial Catheter-Directed CT Angiography for Fenestrated Endovascular Aortic Repair Planning

BACKGROUND

Preoperative planning for fenestrated endovascular aortic repair (fEVAR) requires high-quality cross-sectional imaging, most commonly computed tomography angiography (CTA). However, in the setting of chronic kidney disease (CKD), the iodine load delivered during conventional CTA is associated with risk for acute kidney injury (AKI). In this report, we describe the feasibility of using transarterial catheter directed CT angiography (tcd-CTA) with ultralow-dose iodine as an alternative for fEVAR planning in patients with stage 3-4 CKD to lower the risk of AKI.

METHODS

Preserum and postserum creatinine levels were retrospectively evaluated from 8 patients with stage 3-4 CKD who underwent tcd-CTA with 20 mL of Iohexol for fEVAR planning for the treatment of pararenal abdominal aortic aneurysms. The tcd-CTA images were evaluated by two vascular surgeons for adequacy for fEVAR planning and progression to fEVAR completion was recorded.

RESULTS

The mean serum creatinine before tcd-CTA was 2.1 ± .32 mg/dL, and the mean estimated glomerular filtration rate was 29.7 ± 6.31 mL/min/1.73 m(2). After tcd-CTA, the mean serum creatinine was 1.9 ± .25 mg/dL and the mean estimated glomerular filtration rate was 32.9 ± 5.12 mL/min/1.73 m(2). All 8 of the studies were determined to be adequate for fEVAR planning independently by two vascular surgeons. Six of the patients underwent successful fEVAR and 2 opted for watchful waiting.

CONCLUSIONS

tcd-CTA with ultralow-dose iodine is a feasible option for pre-fEVAR planning in patients with stage 3-4 CKD.

Sulforaphane Attenuates Contrast-Induced Nephropathy in Rats via Nrf2/HO-1 Pathway

Background. Oxidative stress plays an important role in the pathogenesis of contrast-induced nephropathy (CIN). The aim of this study was to investigate the antioxidant effects of sulforaphane (SFN) in a rat model of CIN and a cell model of oxidative stress in HK2 cells. Methods. Rats were randomized into four groups (n = 6 per group): control group, Ioversol group (Ioversol-induced CIN), Ioversol + SFN group (CIN rats pretreated with SFN), and SFN group (rats treated with SFN). Renal function tests, malondialdehyde (MDA), and reactive oxygen species (ROS) were measured. Western blot, real-time polymerase chain reaction analysis, and immunohistochemical analysis were performed for nuclear factor erythroid-derived 2-like 2 (Nrf2) and heme oxygenase-1 (HO-1) detection. Results. Serum blood urea nitrogen (BUN), creatinine, and renal tissue MDA were increased after contrast exposure. Serum BUN, creatinine, and renal tissue MDA were decreased in the Ioversol + SFN group as compared with those in the Ioversol group. SFN increased the expression of Nrf2 and HO-1 in CIN rats and in Ioversol-induced injury HK2 cells. SFN increased cell viability and attenuated ROS level in vitro. Conclusions. SFN attenuates experimental CIN in vitro and in vivo. This effect is suggested to activate the Nrf2 antioxidant defenses pathway.

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.

Renin-angiotensin system inhibitors linked to anemia: a systematic review and meta-analysis

BACKGROUND

The objective of this meta-analysis was to evaluate the risk of anemia in patients who received renin-angiotensin system (RAS) inhibitors.

METHODS

A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception through November, 2014. Studies that reported relative risks, odd ratios or hazard ratios comparing the anemia risk in patients who received angiotensin-converting-enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) vs. those who did not were included. We performed the prespecified sensitivity analysis including only only studies with confounder adjusted analysis. Pooled risk ratios (RRs) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

RESULTS

Seven studies (2 cohort and 5 cross-sectional studies) with 29,061 patients were included in the analysis to assess the risk of anemia and the RAS inhibitors use. The pooled RR of anemia in patients receiving ACEIs was 1.56 (95% CI, 1.40-1.73, I(2) = 17%). When meta-analysis was limited only to studies with confounder adjusted analysis, the pooled RR of anemia in patients using ACEIs was 1.57 (95% CI, 1.43-1.73, I(2) = 0%) The pooled RR of anemia in patients receiving ARBs was 1.60 (95% CI, 1.27-2.00, I(2) = 39%). The meta-analysis of studies with confounder adjusted analysis demonstrated the pooled RR of anemia in patients using ARBs of 1.59 (95% CI, 1.38-1.83, I(2) = 0%).

CONCLUSIONS

Our meta-analysis demonstrates an association between anemia and the use of RAS inhibitors. Hematological parameters should be monitored in patients treated with RAS inhibitors.

Systematic oral hydration with water is similar to parenteral hydration for prevention of contrast-induced nephropathy: an updated meta-analysis of randomised clinical data

Background

Contrast-induced nephropathy (CIN) is the third most common cause of hospital-acquired kidney injury and is related to increased long-term morbidity and mortality. Adequate intravenous (IV) hydration has been demonstrated to lessen its occurrence. Oral (PO) hydration with water is inexpensive and readily available but its role for CIN prevention is yet to be determined.

Methods

PubMed, EMBASE and the Cochrane Central register of controlled trials (CENTRAL) databases were searched until April 2015 and studies were selected using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. All randomised clinical trials with head-to-head comparison between PO and IV hydration were included.

Results

A total of 5 studies with 477 patients were included in the analysis, 255 of those receiving PO water. The incidence of CIN was statistically similar in the IV and PO arms (7.7% and 8.2%, respectively; relative risk 0.97; 95% CI 0.36 to 2.94; p=0.95). The incidence of CIN was statistically similar in the IV and PO arms in patients with chronic kidney disease and with normal renal function. Rise in creatinine at 48–72 h was lower in the PO hydration group compared with IV hydration (pooled standard mean difference 0.04; 95% CI 0.03 to 0.06; p<0.001; I²=62%).

Conclusions

Our meta-analysis shows that systematic PO hydration with water is at least as effective as IV hydration with saline to prevent CIN. PO hydration is cheaper and more easily administered than IV hydration, thus making it more attractive and just as effective.

Comparison of Intravenous and Oral Hydration in the Prevention of Contrast-Induced Acute Kidney Injury in Low-Risk Patients: A Randomized Trial

AIMS

Contrast-induced acute kidney injury (CI-AKI) is a common cause of renal failure. We evaluated the effectiveness of oral sodium citrate versus intravenous (IV) sodium bicarbonate for CI-AKI prophylaxis as well as their influence on kidney injury biomarkers.

MATERIAL AND METHODS

A randomized, controlled, single-center study including 130 hospitalized patients (62.3% men), who were randomized to receive sodium bicarbonate (1/6 men, 3 ml/kg/h for 1 h; n = 43), oral sodium citrate (75 ml/10 kg divided into 4 doses; n = 43) or nonspecific hydration (n = 44) before contrast administration, was conducted. Serum creatinine and kidney injury biomarkers (cystatin C, neutrophil gelatinase-associated lipocalin, interleukin-8, F2-isoprostanes and cardiotrophin-1 [CT-1]) were assessed.

RESULTS

Incidence of CI-AKI was 9.2% with no differences found between hydration groups: 7.0% in sodium bicarbonate group, 11.6% in oral sodium citrate group and 9.1% in the nonspecific hydration group. Urinary creatinine and urinary CT-1/creatinine ratio decreased 4 h after contrast infusion (p < 0.001), but none of the biomarkers assessed were affected by the treatments.

CONCLUSIONS

There were no differences in hydration with oral sodium citrate and IV sodium bicarbonate for the prophylaxis of CI-AKI. Therefore, oral hydration represents a safe, inexpensive and practical method for preventing CI-AKI in low-risk patients. No effect on biomarkers for kidney injury could be demonstrated.