A randomized trial of saline hydration to prevent contrast nephropathy in chronic renal failure patients

Randomized trial to assess the potential role of ascorbic acid and statin for post-contrast acute kidney injury prevention

PURPOSE

To evaluate the effect of using statins and ascorbic acid for the prevention of post-contrast acute kidney injury (PC-AKI) in patients undergoing urologic diagnostic elective contrast-enhanced computed tomography (CECT).

METHODS

This registered trial (NCT03391830) was for statin naïve patients underwent elective CECT. Patients were randomized allocated to two groups: the first group received atorvastatin 80-mg the day before the study and atorvastatin 40-mg two hours before the CECT and for continue on atorvastatin 40-mg two days after CECT; plus ascorbic acid 500 mg with atorvastatin. The other group received two tablets of placebo once/daily before the procedure and for another 3 days. The primary outcome was to assess the incidence PC-AKI.

RESULTS

The baseline parameters were comparable between both groups. The final median (interquartile range "IQR") serum creatinine were 0.80 (0.60, 1.00) and 0.80 (0.60, 1.00), respectively, with insignificant p-value (p = 0.8). The median (IQR) final estimated GFR were 95.2 (72.8, 108.1) and 88.6 (71.9, 111.0) mL/min in placebo and statin plus ascorbic acid groups, respectively (p = 0.48). The eGFR difference median (IQR) were - 6.46 (- 11.72, - 4.18) and - 6.57 (- 13.38, - 3.82) ml/min in placebo and statin plus ascorbic acid groups, respectively (p = 0.58). PC-AKI occurred in 11 patients (9.8%) in placebo group and in 3 patients (3%) in statin plus ascorbic acid group (p = 0.04).

CONCLUSIONS

Statin and ascorbic acid did not statistically improve neither serum creatinine nor eGFR values in patient underwent CECT. However, it can decrease the incidence of the clinically insignificant PC-AKI.

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.

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.

A Simplified Risk Score to Estimate the Risk of Contrast-Induced Nephropathy after Contrast Exposure

Introduction

Scores are available to predict the probability of contrast-induced nephropathy (CIN) after cardiac interventions, but not many scores are available for non-cardiac interventions and there are none for intravenous exposure to contrast. We designed this study to develop a simplified score to determine the probability of developing CIN in patients exposed to the parenteral contrast medium.

Methods

This was a prospective study of patients who received parenteral contrast. Of 1300 patients, the first 1000 comprised the derivation cohort and the next 300 comprised the validation cohort. The patient variables in the development cohort were studied using univariate analysis. Statistically significant individual variables were used as independent variables, and CIN was used as the dependent variable in the final multivariate logistic regression model. Then, the risk score was obtained and validated.

Results

The incidence of CIN was 3.8%. The risk factors, namely the presence of diabetes mellitus, e-GFR, and route and volume of contrast material were significantly associated with the risk of CIN (P < 0.05). The developed risk score had a sensitivity of 90.4% and specificity of 98.78%. The overall accuracy was 97.8%. The values of AUC of ROC in the development and validation datasets were high. This indicated that the predicted CIN risk score correlated well with the calibration and discriminative characteristics.

Conclusions

The route and volume of contrast administered, low e-GFR, and diabetes mellitus were the significant risk factors. The developed risk score exhibited very good sensitivity and specificity and excellent accuracy in predicting the probability of CIN.

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.

Effect of Oral Hydration on Contrast-Induced Acute Kidney Injury among Patients after Primary Percutaneous Coronary Intervention

OBJECTIVES

The purpose of this study was to evaluate the protective effect of oral hydration volume to weight ratio (OHV/W) on contrast-induced acute kidney injury (CI-AKI) among patients with ST-elevation myocardial infarction (STEMI) following percutaneous coronary intervention (PCI).

METHODS

A total of 754 patients with STEMI undergoing PCI were selected. Each patient was encouraged to drink as much water as possible 24 h after PCI. Total volume intake was recorded for all patients. The ratio of OHV/W was calculated. The occurrence of CI-AKI was defined as ≥0.5 mg/dL absolute or ≥25% relative increase in serum creatinine within 48-72 h following PCI. Logistic regression analysis and generalized additive model were performed to evaluate the relationship between OHV/W and CI-AKI.

RESULTS

There was a nonlinear relationship between OHV/W and CI-AKI with an inflection point of 15.69 mL/kg. On the right side of the inflection point (OHV/W ≥15.69 mL/kg), a negative relationship was detected between OHV/W and CI-AKI (HR = 0.90, 95% CI: 0.82∼0.98, p = 0.0126). However, no relationship was observed between OHV/W and CI-AKI on the left of inflection point (HR = 1.19, 95% CI: 0.95∼1.49, p = 0.1302). Subgroup analysis showed that significant interactions were observed only for gender difference (p for interaction = 0.0155), male patients had a significantly lower risk of CI-AKI (HR = 0.84, 95% CI: 0.75∼0.93, p = 0.0012).

CONCLUSION

OHV/W ≥15.6 mL/kg for 24 h post-procedure may be an effective preventive strategy of CI-AKI. In addition, male patients may particularly benefit from OHV to prevent CI-AKI.

Does the cardiovascular drug levosimendan prevent iodinated contrast medium nephrotoxicity with glycerol aggravation in rats?

Background

We investigated whether levosimendan prevents contrast medium nephrotoxicity with glycerol aggravation in rats.

Methods

Forty-eight Wistar albino rats were assigned to eight groups (n = 6 × 8). No medication was administered to group I (controls); glycerol (intramuscular injection of 25% glycerol, 10 mL/kg) group II; intravenous iohexol 10 mL/kg to group III; glycerol and iohexol to group IV; iohexol and intraperitoneal levosimendan 0.25 mg/kg to group V; glycerol, iohexol, and levosimendan 0.25 mg/kg to group VI; iohexol and levosimendan 0.5 mg/kg to group VII; and glycerol, iohexol, and levosimendan 0.5 mg/kg to group VIII. One-day water withdrawal and glycerol injection prompted renal damage; iohexol encouraged nephrotoxicity; levosimendan was administered 30 min after glycerol injection and continued on days 2, 3, and 4. The experiment was completed on day 5. Serum blood urea nitrogen (BUN) and creatinine levels, superoxide dismutase (SOD) activity, glutathione (GSH), malondialdehyde (MDA) levels, tumour necrosis factor-α (TNF-α), nuclear factor kappa ß (NFK-ß), interleukin 6 (IL-6), and histopathological marks were assessed. One-way analysis of variance and Duncan’s multiple comparison tests were used.

Results

Levosimendan changed serum BUN (p = 0.012) and creatinine (p = 0.018), SOD (p = 0.026), GSH (p = 0.012), and MDA (p = 0.011). Levosimendan significantly downregulated TNF-α (p = 0.022), NFK-ß (p = 0.008), and IL-6 (p = 0.033). Histopathological marks of hyaline and haemorrhagic cast were improved in levosimendan-injected groups.

Conclusion

Levosimendan showed nephroprotective properties due to its vasodilator, oxidative distress decreasing and inflammatory cytokine preventing belongings.

[ESUR recommendations on the use of contrast media: Practice survey, review and commentary by CJN, FIRN and SFNDT]

Contrast media administration is classically considered to cause or worsen kidney failure. Recent data may moderate this assertion. The European Society of Urogenital Radiology recently published guidelines re-evaluating the precautions before administering contrast media. The present work evaluates the practice of French nephrologists, and provides a commentary on these recommendations based on an updated review of the literature. We conducted survey among French nephrologists, using an electronic questionnaire distributed by the Société Francophone de Néphrologie, Dialyse et Transplantation, the French Intensive care Renal Network and the Club des Jeunes Néphrologues. 266 responses were collected. The European Society of Urogenital Radiology guidelines are poorly known among the panel of nephrologists. Their practices differ from the guidelines by the more frequent and earlier implementation of measures to prevent renal failure post contrast media. In accordance with the guidelines, hydration is prescribed as a first-line preventive measure, mainly with saline and bicarbonate. Inhibitors of the renin-angiotensin-aldosterone system are frequently discontinued before an injection of contrast media, contrary to what is recommended. In conclusion, the European Society of Urogenital Radiology guidelines, which the working group endorses, but which are still too little known and applied in clinical nephrology in France, prompt nephrologists to lift some of the restrictions on the use of PCI as well as on the continuation of ARS inhibitors before injecting PCI.

Preventing a nonexistent entity: the curious case of contrast and acute kidney injury

PURPOSE OF REVIEW

In recent years, doubt has been cast on the existence of contrast-induced acute kidney injury. The skepticism has stemmed from observational studies from large administrative healthcare databases. Although they correctly call that contrast-induced acute kidney injury is less common than previously thought, they cannot completely exclude selection bias.

RECENT FINDINGS

Though less common than previously thought, contrast-induced acute kidney injury still exists. The only prophylactic method that remains valid is that of isotonic volume expansion, which is still deemed beneficial in high-risk patients. N-acetylcysteine and sodium bicarbonate are ineffective and their use should be abandoned.

SUMMARY

Contrast-induced kidney injury should be defined based on clinical grounds, not merely on biochemical numbers. More research to validate a clinical definition is necessary in order to accurately re-examine its incidence.

Kidney and contrast media: Common viewpoint of the French Nephrology societies (SFNDT, FIRN, CJN) and the French Radiological Society (SFR) following ESUR guidelines

Contrast medium administration is classically considered to cause or worsen kidney failure, but recent data may moderate this assertion. The European Society of Urogenital Radiology recently published guidelines re-evaluating the precautions before administering contrast media. Kidney injury does not constitute a contra-indication to the administration of iodinated contrast medium, as long as the benefit-risk ratio justifies it. Intravenous hydration with 0.9% NaCl or 1.4% sodium bicarbonate is the only validated measure for the prevention of post-iodine contrast nephropathy. This is necessary for intravenous or intra-arterial administration of iodinated contrast agent without first renal pass when the glomerular filtration rate is less than 30mL/min/1.73m², for intra-arterial administration of iodinated contrast agent with first renal passage when the glomerular filtration rate is less than 45mL/min/1.73m², or in patients with acute renal failure. The use of iodinated contrast medium should allow the carrying out of relevant examinations based on an analysis of the benefit-risk ratio and the implementation of measures to prevent toxicity when necessary.

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.

Comparing Trimetazidine with Allopurinol in Prevention of Contrast Induced Nephropathy After Coronary Angiography

Objectives

Contrast-induced nephropathy is considered a serious complication following coronary angiography increasing morbidity and mortality. Various drugs have been assessed to reduce the incidence of contrast-induced nephropathy. In this study, we compared trimetazidine and allopurinol as a pharmacological measure to reduce the incidence of contrast-induced nephropathy.

Methods

One hundred and twenty patients undergoing coronary angiography with baseline creatinine clearance more than 30 ml/minute were divided into three groups, 40 patients each. Group 1 received standard parenteral intravenous hydration in the form of isotonic saline at a rate of 1 ml/kg body weight per hour started 12 hours before angiography and up to 12 hours after the procedure. Group 2 received trimetazidine 35 mg twice per day for 72 hours starting 48 hours before the procedure in addition to intravenous hydration. Group 3 received allopurinol 300 mg once daily for 72 hours starting 48 hours before the procedure in addition to intravenous hydration. Serum creatinine and creatinine clearance were measured before and 72 hours after the procedure in addition to the volume of contrast media used.

Results

Trimetazidine and allopurinol failed to reduce contrast-induced nephropathy significantly. Among patients with contrast-induced nephropathy volume of contrast media was significantly higher.

Conclusion

Adding trimetazidine or allopurinol in addition to regular intravenous hydration with isotonic saline without targeting selectively high-risk patients did not reduce contrast-induced nephropathy following coronary angiography.

Effect of Combining Furosemide With Standard Hydration Therapy on Contrast-Induced Acute Kidney Injury Following Coronary Angiography or Intervention in a High-Risk Population

This study aimed to investigate whether combining furosemide with standard hydration therapy results in increased preventive effects on contrast-induced acute kidney injury (CI-AKI) following coronary angiography (CA) or percutaneous coronary intervention (PCI). Patients (n = 230) were enrolled in the study and were randomized to the furosemide group or the control group. Patients in the furosemide group received 0.2 to 0.5 mg/kg of furosemide as a continuous intravenous infusion for 24 hours postoperatively and the same standard hydration regimen received by the control group. Blood samples were obtained 24 hours before and 48 hours after the procedure and urine volume was recorded postprocedure. Patients were followed up for an average of 6 months after the procedure. The incidence of CI-AKI in the furosemide group was significantly lower than that in the control group (8.7% vs 18.3%, P = .034). Multivariate logistic regression showed that age-glomerular filtration rate-ejection fraction score and V/estimated glomerular filtration rate ratio were independent risk factors for CI-AKI. During the average 6-month follow-up, incidence of major adverse cardiovascular events (MACEs) in the furosemide group was also significantly lower. Furosemide combined with standard hydration therapy may reduce the incidence of CI-AKI and MACEs following CA or PCI.

The place of hydration using intravenous fluid in patients at risk of developing contrast-associated nephropathy

There has been a significant rise in the incidence of contrast-associated nephropathy caused by administration of contrast media during cardiac interventions. This is one of the major complications of percutaneous coronary interventions, which may proceed to acute renal failure. Risk factors, including pre-existing renal dysfunction, older age and use of high osmolar contrast media, predispose patients to the development of contrast-associated nephropathy. Different risk-reduction strategies have been used to prevent contrast-associated nephropathy, including use of low osmolar contrast media, N-acetylcysteine, alkalisation of tubular fluid with intravenous sodium bicarbonate, and oral and intravenous hydration with isotonic solution. Hydration using intravenous saline is one of the main treatments used to prevent the development of nephropathy in patients receiving contrast media during cardiac interventions. Prehydration, before administering contrast media, seems to be crucial. The results of studies of the relative efficacy of sodium bicarbonate and/or N-acetylcysteine in reducing the development of contrast-associated nephropathy are not consistent and any beneficial effects may depend on the pre-existing state of the kidney. This review discusses hydration of patients who are at risk of developing contrast-associated nephropathy using intravenous fluid.

Point-of-care creatinine tests to assess kidney function for outpatients requiring contrast-enhanced CT imaging: systematic reviews and economic evaluation

BACKGROUND

Patients with low estimated glomerular filtration rates may be at higher risk of post-contrast acute kidney injury following contrast-enhanced computed tomography imaging. Point-of-care devices allow rapid measurement of estimated glomerular filtration rates for patients referred without a recent estimated glomerular filtration rate result.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of point-of-care creatinine tests for outpatients without a recent estimated glomerular filtration rate measurement who need contrast-enhanced computed tomography imaging.

METHODS

Three systematic reviews of test accuracy, implementation and clinical outcomes, and economic analyses were carried out. Bibliographic databases were searched from inception to November 2018. Studies comparing the accuracy of point-of-care creatinine tests with laboratory reference tests to assess kidney function in adults in a non-emergency setting and studies reporting implementation and clinical outcomes were included. Risk of bias of diagnostic accuracy studies was assessed using a modified version of the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Probabilities of individuals having their estimated glomerular filtration rates correctly classified were estimated within a Bayesian framework and pooled using a fixed-effects model. A de novo probabilistic decision tree cohort model was developed to characterise the decision problem from an NHS and a Personal Social Services perspective. A range of alternative point-of-care testing approaches were considered. Scenario analyses were conducted.

RESULTS

Fifty-four studies were included in the clinical reviews. Twelve studies reported diagnostic accuracy for estimated glomerular filtration rates; half were rated as being at low risk of bias, but there were applicability concerns for most. i-STAT (Abbott Point of Care, Inc., Princeton, NJ, USA) and ABL (Radiometer Ltd, Crawley, UK) devices had higher probabilities of correctly classifying individuals in the same estimated glomerular filtration rate categories as the reference laboratory test than StatSensor® devices (Nova Biomedical, Runcorn, UK). There was limited evidence for epoc® (Siemens Healthineers AG, Erlangen, Germany) and Piccolo Xpress® (Abaxis, Inc., Union City, CA, USA) devices and no studies of DRI-CHEM NX 500 (Fujifilm Corporation, Tokyo, Japan). The review of implementation and clinical outcomes included six studies showing practice variation in the management decisions when a point-of-care device indicated an abnormal estimated glomerular filtration rate. The review of cost-effectiveness evidence identified no relevant studies. The de novo decision model that was developed included a total of 14 strategies. Owing to limited data, the model included only i-STAT, ABL800 FLEX and StatSensor. In the base-case analysis, the cost-effective strategy appeared to be a three-step testing sequence involving initially screening all individuals for risk factors, point-of-care testing for those individuals with at least one risk factor, and including a final confirmatory laboratory test for individuals with a point-of-care-positive test result. Within this testing approach, the specific point-of-care device with the highest net benefit was i-STAT, although differences in net benefit with StatSensor were very small.

LIMITATIONS

There was insufficient evidence for patients with estimated glomerular filtration rates < 30 ml/minute/1.73 m2, and on the full potential health impact of delayed or rescheduled computed tomography scans or the use of alternative imaging modalities.

CONCLUSIONS

A three-step testing sequence combining a risk factor questionnaire with a point-of-care test and confirmatory laboratory testing appears to be a cost-effective use of NHS resources compared with current practice. The risk of contrast causing acute kidney injury to patients with an estimated glomerular filtration rate of < 30 ml/minute/1.73 m2 is uncertain. Cost-effectiveness of point-of-care testing appears largely driven by the potential of point-of-care tests to minimise delays within the current computed tomography pathway.

FUTURE WORK

Studies evaluating the impact of risk-stratifying questionnaires on workflow outcomes in computed tomography patients without recent estimated glomerular filtration rate results are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018115818.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 39. See the NIHR Journals Library website for further project information.

Hydration: Intravenous and Oral: Approaches, Principals, and Differing Regimens: Is It What Goes in or What Comes Out That Is Important?

The literature (in English) was accessed to review the evidence that administration of fluids is protective of contrast-associated acute kidney injury (CA-AKI). The evidence was evaluated with the intent of understanding mechanisms of protection. Prospective randomized trials comparing oral versus intravenous fluid, sodium chloride versus no intravenous fluid, sodium bicarbonate versus sodium chloride, and forced matched hydration versus intravenous sodium chloride provided the data. In general, the more fluid administered, the lower the incidence of CA-AKI. However, understanding the mechanism of this beneficial effect suggests that it is the urine output that most directly affects the incidence of CA-AKI.

Hydration Strategies for Preventing Contrast-Induced Acute Kidney Injury: A Systematic Review and Bayesian Network Meta-Analysis

Aims

Many previous studies have examined the effect of different hydration strategies on prevention of contrast-induced acute kidney injury (CI-AKI), but the optimal strategy is unknown. We performed a network meta-analysis (NWM) of these previous studies to identify the optimal strategy.

Methods and Results

Web of Science, PubMed, OVID Medline, and Cochrane Library were searched from their inception dates to September 30, 2018. Randomized controlled trials (RCTs) were selected based on strict inclusion criteria, and a Bayesian NWM was performed using WinBUGS V.1.4.3. We finally analyzed 60 eligible RCTs, which examined 21,293 patients and 2232 CI-AKI events. Compared to intravenous 0.9% sodium chloride (reference), intravenous sodium bicarbonate (OR [95% CI]: 0.74 [0.57, 0.93]), hemodynamic guided hydration (0.41 [0.18, 0.93]), and RenalGuard guided hydration (0.32 [0.14, 0.70]) significantly reduced the occurrence of CI-AKI. Oral hydration and intravenous 0.9% sodium chloride were each noninferior to no hydration in preventing CI-AKI. Intravenous 0.9% sodium chloride, sodium bicarbonate, and hemodynamic guided hydration were each noninferior to oral hydration in preventing CI-AKI. Based on surface under the cumulative ranking curve values, the RenalGuard system was best (0.974) and hemodynamic guided hydration was second best (0.849).

Conclusion

There was substantial evidence to support the use of RenalGuard or hemodynamic guided hydration for preventing CI-AKI in high-risk patients, especially those with chronic kidney disease or cardiac dysfunction.

Loop Diuretics in Acute Kidney Injury Prevention, Therapy, and Risk Stratification

BACKGROUND

Loop diuretics (LD) are widely used in emergency and intensive care medicine.

SUMMARY

The substances increase the clearance of electrolytes and water; thus, they allow us to control hypervolemia and to prevent patients from pulmonary edema. LD are also frequently applied to patients with an acute decrease in glomerular filtration rate, namely, acute kidney injury (AKI). Nevertheless, volume depletion may be associated with reduced renal perfusion and possibly slower restitution or even aggravation of kidney dysfunction. Several trials on the preventive or therapeutic efficacy of LD have been published since the early 1970s. Our review article is intended to summarize the most important references related to this topic. In addition, we discuss the diagnostic value of the so-called furosemide stress test. The currently available data indicate that LD may act in a beneficial manner as long as euvolemia is maintained (matched hydration). Key Massages: LD are not beneficial for AKI treatment if kidney-related endpoints are considered. In certain situations, AKI prevention with LD can be associated with favorable outcomes as long as euvolemia is maintained. LD can help to identify AKI subjects at a higher risk of AKI progression, but the exact clinical consequences need to be determined.

Impact of furosemide on mortality and the requirement for renal replacement therapy in acute kidney injury: a systematic review and meta-analysis of randomised trials

OBJECTIVE

To examine the impact of furosemide on mortality and the need for renal replacement therapy (RRT) in adult patients with acute kidney injury (AKI) based on current evidence.

DATA SOURCES

PubMed (Medline) and Embase were searched from 1998 to October 2018.

STUDY SELECTION

We retrieved data from randomised controlled trials comparing prevention/treatment with furosemide at any stage of AKI with alternative treatment/standard of care/placebo. The outcome was short-term mortality and the requirement for RRT, when applicable.

DATA EXTRACTION

Two reviewers independently extracted appropriate data. PRISMA guidelines were followed for data preparation and reporting.

DATA SYNTHESIS

We identified 20 relevant studies (2608 patients: 1330 in the treatment arm and 1278 in the control arm). Heterogeneity between studies was deemed acceptable, and the publication bias was low. Furosemide had neither an impact on mortality (OR = 1.015; 95% CI 0.825-1.339) nor the need for RRT (OR = 0.947; 95% CI 0.521-1.721). Furosemide had also no effect on the outcomes in strata defined by intervention strategy (prevention/treatment), AKI origin (cardio-renal syndrome, post-cardiopulmonary bypass, critical illness), control arm comparator (RRT, saline/placebo/standard of care) and its dose (< 160/≥ 160 mg) (p > 0.05 for all). Subjects who received furosemide with matched hydration in prevention of contrast-induced nephropathy (CIN) had a less frequent need for RRT (OR = 0.218; 95% CI 0.05-1.04; p = 0.055).

CONCLUSIONS

Furosemide administration has neither an impact on mortality nor the requirement for RRT. Patients at risk of CIN may benefit from furosemide administration. Further well-designed RCTs are needed to verify these findings.

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.

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.

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.

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.

Metabolic Syndrome and the Iodine-Dose/Creatinine Clearance Ratio as Determinants of Contrast-Induced Acute Kidney Injury

BACKGROUND

Finding patients at risk of developing contrast-induced acute kidney injury (CI-AKI) is important because of its associated complications. In the present study, the contribution of different variables, such as the presence of metabolic syndrome (MetS), the volume creatinine clearance (V/CrCl) ratio, the iodine-dose (I-dose)/CrCl ratio, or hypertension, to CI-AKI was evaluated.

METHODS

A total of 255 patients undergoing elective coronary angiography with or without intervention were enrolled and divided into a MetS and a control group. All patients were assessed for the development of CI-AKI after the procedures.

RESULTS

CI-AKI occurred in 39.23% (51 of 130) of the MetS patients and 14.4% (18 of 125) of the control group (p < 0.001). The multivariable regression model showed that male sex and the use of statins decreased the risk of CI-AKI, and high triglyceride levels, I-dose/CrCl > 0.52, MetS, CrCl ≤60 mL/min, and age ≥70 years increased the risk of CI-AKI, independent of confounding factors. The difference in the mean V/CrCl ratio was statistically significant between patients who developed CI-AKI and those who did not show renal impairment (2.36 ± 1.35 vs. 1.43 ± 0.89, respectively; p < 0.001). The ROC curve analysis of I-dose/CrCl determined the best cutoff value for patients with and those without MetS as 0.51 and 0.63, with a sensitivity value of 68 and 72% and a specificity value of 73 and 74%, respectively.

CONCLUSIONS

We showed that MetS is a strong risk factor for CI-AKI in nondiabetic patients undergoing elective coronary interventions; and the I-dose/CrCl ratio is a strong predictor of CI-AKI in these patients. We suggest that clinicians identify MetS patients and calculate their I-dose/CrCl ratio before coronary interventions.

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.

RenalGuard system to prevent contrast-induced acute kidney injury in Japanese patients with renal dysfunction; RESPECT KIDNEY study

Increasing the urine flow rate (UFR) reduces the toxic effect of contrast media. Use of the RenalGuard system enables the achievement of a high UFR by maintaining intravascular volume and prevents the development of contrast-induced acute kidney injury (CI-AKI). However, the efficacy and safety of RenalGuard system have not yet been evaluated in Japan. This multicenter prospective study evaluated the efficacy and safety of the RenalGuard therapy in preventing CI-AKI development in 60 Japanese patients with renal dysfunction [estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m²] undergoing catheter procedures. Baseline eGFR and Mehran's CIN (contrast-induced nephropathy) risk score were 35.1 ± 8.5 mL/min/1.73 m² and 11.7 ± 4.3, respectively. Regardless of this high-risk profile, the incidence of CI-AKI was 8.6% (5/58) compared with the 26.1% incidence estimated by the CIN risk score. Moreover, two-sided 95% (Fisher's) exact confidence interval was 2.9-19.0 and its upper limit (i.e., 19.0) was less than the prespecified threshold incidence of 25.0. Univariate logistic regression analysis demonstrated that the UFR during catheter procedure was one of the most important factor associated with CI-AKI (odds ratio 0.99, confidence interval 0.98-1.00, p = 0.03). In conclusion, RenalGuard therapy may prevent CI-AKI development in Japanese patients with renal dysfunction. Further large-scale prospective multicenter studies are necessary to confirm our findings.

Intermittent furosemide administration in patients with or at risk for acute kidney injury: Meta-analysis of randomized trials

Background

Furosemide is the most common loop diuretic used worldwide. The off-label administration of furosemide bolus(es) for the prevention or to reverse acute kidney injury (AKI) is widespread but not supported by available evidence. We conducted a meta-analysis of randomized trials (RCTs) to investigate whether bolus furosemide to prevent or treat AKI is detrimental on patients’ survival.

Methods

Electronic databases were searched through October 2017 for RCTs comparing bolus furosemide administration versus any comparator in patients with or at risk for AKI. The primary endpoint was all-cause longest follow-up mortality. Secondary endpoints included new or worsening AKI, receipt of renal replacement therapy, length of hospital stay, and peak serum creatinine after randomization.

Results

A total of 28 studies randomizing 3,228 patients were included in the analysis. We found no difference in mortality between the two groups (143/892 [16%] in the furosemide group versus 141/881 [16%] in the control group; odds ratio [OR], 0.84; 95% confidence interval [CI], 0.63 to 1.13; p = 0.25). No significant differences in secondary outcomes were found. A significant improvement in survival was found in the subgroup of patients receiving furosemide bolus(es) as a preventive measure (43/613 [7.0%] versus 67/619 [10.8%], OR 0.62; 95% CI, 0.41 to 0.94; p = 0.03)

Conclusions

Intermittent furosemide administration is not associated with an increased mortality in patients with or at risk for AKI, although it may reduce mortality when used as a preventive measure. Future high-quality RCTs are needed to define the role of loop diuretics in AKI prevention and management.

Trial registration

The study protocol was registered on PROSPERO database for systematic reviews (Registration no. CRD42017078607 – http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42017078607).

Contrast-Induced Nephropathy and Oxygen Pretreatment in Patients With Impaired Renal Function

INTRODUCTION

Contrast-induced nephropathy is a complication following coronary angiography and percutaneous coronary intervention. Because contrast-induced nephropathy is a predictor of long-term mortality in patients with ischemic heart disease undergoing percutaneous coronary intervention, preventive strategies are required. We assessed the effects of periprocedural oxygenation on contrast-induced nephropathy among patients with pre-existing renal dysfunction.

METHODS

A total of 200 consecutive patients with impaired renal function (estimated glomerular filtration < 60 ml/min per 1.73 m2) undergoing elective cardiovascular angiography were randomly assigned to an oxygenation treatment (n = 100) or control group (n = 100). In oxygenation treatment, pure oxygen (2 L/min) was administered for 10 minutes before exposure to contrast medium. The primary endpoint was the incidence of contrast-induced nephropathy, defined as a ≥ 25% increase in serum creatinine levels from baseline within 48 hours of exposure.

RESULTS

In the oxygenation treatment group, partial pressure of arterial oxygen was higher (135 ± 25 mm Hg vs. 84 ± 10 mm Hg, P < 0.001); contrast-induced nephropathy incidence was lower (1% vs. 8%, odds ratio [OR] = 0.12, 95% confidence interval [CI] = 0.01-0.95, P = 0.02); and partial pressure of arterial carbon dioxide and bicarbonate base lactate levels were similar compared with those in the control group. Upon univariate analysis, excess and absence of oxygenation treatment (OR = 9.18, CI = 1.13-74.86, P = 0.03) and anemia (OR = 4.30, CI = 1.04-17.78, P = 0.04) were shown to be associated with contrast-induced nephropathy incidence.

CONCLUSION

Oxygenation, a simple, nonpharmacological strategy, may be beneficial when using contrast media in patients with impaired renal function from noninvasive angiography to emergency catheterization.

Contrast-Induced Acute Kidney Injury: Pathophysiology, Manifestations, Prevention, and Management

Contrast-induced acute kidney injury is a phenomenon that has been extensively studied throughout the years. There is a large volume of literature documenting this risk, and most radiology departments and radiologists use this information when making decisions regarding contrast administration. A review of the current information on the topic of contrast-induced acute kidney injury is necessary to ensure that the risks of intravenous contrast are properly weighed against the benefits of a contrast-enhanced computed tomography scan.

Management of patients at risk of acute kidney injury

Acute kidney injury (AKI) is a multifaceted syndrome that occurs in different settings. The course of AKI can be variable, from single hit and complete recovery, to multiple hits resulting in end-stage renal disease. No interventions to improve outcomes of established AKI have yet been developed, so prevention and early diagnosis are key. Awareness campaigns and education for health-care professionals on diagnosis and management of AKI-with attention to avoidance of volume depletion, hypotension, and nephrotoxic interventions-coupled with electronic early warning systems where available can improve outcomes. Biomarker-based strategies have not shown improvements in outcome. Fluid management should aim for early, rapid restoration of circulatory volume, but should be more limited after the first 24-48 h to avoid volume overload. Use of balanced crystalloid solutions versus normal saline remains controversial. Renal replacement therapy should only be started on the basis of hard criteria, but should not be delayed when criteria are met. On the basis of recent evidence, the risk of contrast-induced AKI might be overestimated for many conditions.

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.

Imaging patients with renal impairment

Imaging with intravascular contrast media is generally considered safe, particularly in patients without renal failure. However, as renal function deteriorates, the potential risk of nonallergic-type adverse events increases. This presents a unique challenge, particularly when the use of intravenous contrast media is deemed essential for diagnostic purposes. Following a discussion regarding the definition and epidemiology of kidney injury, this review focuses on the evolving understanding of both contrast-induced nephropathy and nephrogenic systemic fibrosis and discusses preventative strategies aimed at minimizing the risk of developing these entities. Alternative non-contrast imaging techniques are also discussed.

A novel approach to contrast-induced nephrotoxicity: the melatonergic agent agomelatine

OBJECTIVE

To study the potential nephroprotective role of agomelatine in rat renal tissue in cases of contrast-induced nephrotoxicity (CIN). The drug's action on the antioxidant system and proinflammatory cytokines, superoxide dismutase (SOD) activity, levels of glutathione (GSH) and malondialdehyde (MDA) and the gene expression of interleukin-6 (IL-6), tumour necrosis factor (TNF)-α and nuclear factor kappa B (NF-κB) was measured. Tubular necrosis and hyaline and haemorrhagic casts were also histopathologically evaluated.

METHODS

The institutional ethics and local animal care committees approved the study. Eight groups of six rats were put on the following drug regimens: Group 1: healthy controls, Group 2: GLY (glycerol), Group 3: CM (contrast media--iohexol 10 ml kg(-1)), Group 4: GLY+CM, Group 5: CM+AGO20 (agomelatine 20 mg kg(-1)), Group 6: GLY+CM+AGO20, Group 7: CM+AGO40 (agomelatine 40 mg kg(-1)) and Group 8: GLY+CM+AGO40. The groups were evaluated by one-way analysis of variance and Duncan's multiple comparison test.

RESULTS

Agomelatine administration significantly improved the serum levels of blood urea nitrogen (BUN) and creatinine, SOD activity, GSH and MDA. The use of agomelatine had substantial downregulatory consequences on TNF-α, NF-κB and IL-6 messenger RNA levels. Mild-to-severe hyaline and haemorrhagic casts and tubular necrosis were observed in all groups, except in the healthy group. The histopathological scores were better in the agomelatine treatment groups.

CONCLUSION

Agomelatine has nephroprotective effects against CIN in rats. This effect can be attributed to its properties of reducing oxidative stress and inhibiting the secretion of proinflammatory cytokines (NF-κB, TNF-α and IL-6).

ADVANCES IN KNOWLEDGE

CIN is one of the most important adverse effects of radiological procedures. Renal failure, diabetes, malignancy, old age and non-steroidal anti-inflammatory drug use pose the risk of CIN in patients. Several clinical studies have investigated ways to avoid CIN. Theophylline/aminophylline, statins, ascorbic acid and iloprost have been suggested for this purpose. Agomelatine is one of the melatonin ligands and is used for affective disorders and has antioxidant features. In this study, we hypothesized that agomelatine could have nephroprotective, antioxidant and anti-inflammatory effects against CIN in rats.

Evaluation of the protective effect of N-acetylcysteine on contrast media nephropathy

INTRODUCTION

Intravenous contrast agents can cause acute decline in kidney function, especially in patients with risk factors.

OBJECTIVES

In this study, we aimed to examine the ameliorative effect N-acetylcysteine (NAC) to reduce the incidence of contrast nephropathy.

PATIENTS AND METHODS

This study was a prospective, randomized, double-blind clinical trial on 150 patients who underwent coronary angiography. The study was carried out on patients undergoing coronary angiography. Patients were randomly assigned into 2 groups of intervention group and control subjects. Intervention group took NAC 600 mg orally twice a day. It was administered one day before angiography and continued until the second day after angiography. Control subjects received saline only. Serum creatinine was measured before and three days after coronary angiography.

RESULTS

There was no significant difference between intervention and control groups at baseline (P > 0.05). However, there was a significant decline in creatinine level among NAC patients (P = 0.001). Saline group had significantly higher proportion of nephropathy cases than NAC patients Conclusion: We found that the consumption of NAC is useful for contrast induced nephropathy (CIN) prevention.

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.

Acute Kidney Injury With the RenalGuard System in Patients Undergoing Transcatheter Aortic Valve Replacement: The PROTECT-TAVI Trial (PROphylactic effecT of furosEmide-induCed diuresis with matched isotonic intravenous hydraTion in Transcatheter Aortic Valve Implantation)

OBJECTIVES

The purpose of this study was to investigate the effect of the RenalGuard System (PLC Medical Systems, Milford, Massachusetts) on prevention of acute kidney injury (AKI) in patients undergoing transcatheter aortic valve replacement (TAVR).

BACKGROUND

TAVR is associated with varying degrees of post-procedural AKI. The RenalGuard System is a dedicated device designed for contrast-induced AKI prevention. Whether this device is also effective in patients with severe aortic stenosis undergoing TAVR is unexplored.

METHODS

The present is an investigator-driven, single-center, prospective, open-label, registry-based randomized study that used the TAVR institutional registry of the Ferrarotto Hospital in Catania, Italy, as the platform for randomization, data collection, and follow-up assessment. A total of 112 consecutive patients undergoing TAVR were randomly assigned to hydration with normal saline solution controlled by the RenalGuard system and furosemide (RenalGuard group) or normal saline solution (control group). The primary endpoint was the incidence of Valve Academic Research Consortium-defined AKI in the first 72 h after the procedure.

RESULTS

The AKI rate was lower in the RenalGuard group than in the control group (n = 3 [5.4%] vs. n =14 [25.0%], respectively, p = 0.014). The majority of patients (5.4% vs. 23.2%) developed a mild AKI (stage 1); severe damage (stage 3) occurred only in 1 patient in the control group (0.0% vs. 1.8%). No case of in-hospital renal failure requiring dialysis was reported. No significant differences in terms of mortality, cerebrovascular events, bleeding, and hospitalization for heart failure were noted in both groups at 30 days.

CONCLUSIONS

Furosemide-induced diuresis with matched isotonic intravenous hydration using the RenalGuard system is an effective therapeutic tool to reduce the occurrence of AKI in patients undergoing TAVR.

Blood pressure-lowering efficacy of loop diuretics for primary hypertension

BACKGROUND

Antihypertensive drugs from the thiazide diuretic drug class have been shown to reduce mortality and cardiovascular morbidity. Loop diuretics are indicated and used to treat hypertension, but a systematic review of their blood pressure-lowering efficacy or effectiveness in terms of reducing cardiovascular mortality or morbidity from randomized controlled trial (RCT) evidence has not been conducted.

OBJECTIVES

To determine the dose-related decrease in systolic or diastolic blood pressure, or both, as well as adverse events leading to participant withdrawal and adverse biochemical effects (serum potassium, uric acid, creatinine, glucose and lipids profile) due to loop diuretics versus placebo control in the treatment of people with primary hypertension.

SEARCH METHODS

We searched the Cochrane Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, 2014, Issue 9), MEDLINE, MEDLINE In-Process, EMBASE, and ClinicalTrials.gov to 27 October 2014.

SELECTION CRITERIA

We included double-blind randomized placebo-controlled trials of at least three weeks duration comparing loop diuretic with a placebo in people with primary hypertension defined as blood pressure greater than 140/90 mmHg at baseline.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias and extracted data. We used weighted mean difference and a fixed effects model to combine continuous outcome data. We analysed the drop outs due to adverse effects using relative risk ratio.

MAIN RESULTS

Nine trials evaluated the dose-related blood pressure-lowering efficacy of five drugs within the loop diuretics class (furosemide 40 mg to 60 mg, cicletanine 100 mg to 150 mg, piretanide 3 mg to 6 mg, indacrinone enantiomer -2.5 mg to -10.0/+80 mg, and etozolin 200 mg) in 460 people with baseline blood pressure of 162/103 mmHg for a mean duration of 8.8 weeks. The best estimate of systolic/diastolic blood pressure-lowering efficacy of loop diuretics was -7.9 (-10.4 to -5.4) mmHg/ -4.4 (-5.9 to -2.8) mmHg. Withdrawals due to adverse effects and serum biochemical changes did not show a significant difference.We performed additional searches in 2012 and 2014, which found no additional trials meeting the minimum inclusion criteria.

AUTHORS' CONCLUSIONS

Based on the limited number of published RCTs, the systolic/diastolic blood pressure-lowering effect of loop diuretics is -8/-4 mmHg, which is likely an overestimate. We graded the quality of evidence for both systolic and diastolic blood pressure estimates as "low" due to the high risk of bias of included studies and the high likelihood of publication bias. We found no clinically meaningful blood pressure-lowering differences between different drugs within the loop diuretic class. The dose-ranging effects of loop diuretics could not be evaluated. The review did not provide a good estimate of the incidence of harms associated with loop diuretics because of the short duration of the trials and the lack of reporting of adverse effects in many of the trials.

Oral salt and water versus intravenous saline for the prevention of acute kidney injury following contrast-enhanced computed tomography: study protocol for a pilot randomized trial

Background

Although intravenous saline is the accepted prophylactic measure for the prevention of contrast- induced acute kidney injury, the oral route could offer an equivalent, practical, and cost saving approach. A systematic review of randomized trials that compared oral versus intravenous volume expansion for the prevention of radiocontrast-induced nephropathy in patients receiving arterial contrast reported no significant difference in the risk of contrast induced acute kidney injury between the oral and intravenous arms. Most trials for contrast nephropathy prevention have been in the setting of arterial contrast such as with cardiac catheterization, and not with venous contrast, such as computed tomography. The aim of this paper is to describe the protocol of a pilot trial comparing the effect of oral salt and water versus intravenous saline on the prevention of Acute Kidney Injury following contrast-enhanced computed tomography.

Methods

Our study is a pilot, single-centre parallel randomized controlled trial. To be included, participants must be at stage 4 of chronic kidney disease as defined by a glomerular filtration rate <30 mL/min/1.73 m², aged greater than 18 years and to undergo an outpatient contrast-enhanced computer tomography of the chest or abdomen. A total 50 patients will be randomised to receive either oral salt and water or intravenous isotonic saline. The primary outcome is feasibility, including estimates of recruitment rate, adherence to intervention and completeness of follow-up to assist in planning the definitive trial. The secondary outcome is safety and includes adverse events with oral salt and water loading as compared to intravenous isotonic saline.

Discussion

The results of this pilot trial will provide critical information to plan a definitive trial to test the efficacy of the route of volume loading regimens in prevention of acute kidney injury after contrast-enhanced CT scans.

Trial registration

The trial is registered at the US National Institutes of Health (ClinicalTrials.gov) # NCT02084771.

Furosemide with saline hydration for prevention of contrast-induced nephropathy in patients undergoing coronary angiography: a meta-analysis of randomized controlled trials

Background

The clinical efficacy of furosemide administration in preventing contrast-induced nephropathy (CIN) remains uncertain. This meta-analysis was designed to update data on the incidence of CIN with additional furosemide treatment beyond saline hydration in comparison with hydration alone in patients undergoing percutaneous coronary intervention (PCI).

Material/Methods

A computerized literature search of MEDLINE, EMBASE, and Cochrane databases was performed. Trials were eligible if they enrolled patients undergoing coronary angiography and randomly allocated participants to receive furosemide administration in addition to saline hydration or saline hydration alone. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for combinations of studies.

Results

Five trials involving 1294 patients (640 for additional furosemide treatment and 654 for hydration alone) were included in the meta-analysis. In the synthesis of data, additional furosemide administration had little impact on the incidence of CIN post-PCI compared with peri-procedural saline hydration alone (OR=0.96; 95% CI 0.33–2.84, p=0.95). Moreover, as for the subsequent need for dialysis, there was no statistical significant difference between the 2 groups (OR=1.01; 95% CI 0.38–2.67, p=0.99). Sensitivity analyses did not show any relevant influence on the overall results. There was no publication bias in the meta-analysis.

Conclusions

Furosemide administration did not achieve additional benefit beyond saline hydration in reducing the incidence of CIN in patients undergoing PCI.

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.

Efficacy of oral hydration in the prevention of contrast-induced acute kidney injury in patients undergoing coronary angiography or intervention

BACKGROUND

Efficacy of intravenous (IV) volume expansion in preventing contrast-induced acute kidney injury (CI-AKI) is well known. However, the role of oral hydration has not been well established. The aim of this work was to evaluate the efficacy of oral hydration in preventing CI-AKI.

METHODS

We prospectively randomized 225 patients undergoing coronary angiography and/or percutaneous coronary intervention in either oral hydration or IV hydration groups. Patients who have at least one of the high-risk factors for developing CI-AKI (advanced age, type 2 diabetes mellitus, anemia, hyperuricemia, a history of cardiac failure or systolic dysfunction) were included in the study. All patients had normal renal function or stage 1-2 chronic kidney disease. Patients in the oral hydration group were encouraged to drink unrestricted amounts of fluids freely whereas isotonic saline infusion was performed by the standard protocol in the IV hydration group.

RESULTS

CI-AKI occurred in 8/116 patients (6.9%) in the oral hydration group and 8/109 patients (7.3%) in the IV hydration group (p = 0.89). There was also no statistically significant difference between the two groups when different CI-AKI definitions were taken into account.

CONCLUSION

Oral hydration is as effective as IV hydration in preventing CI-AKI in patients with normal kidney function or stage 1-2 chronic kidney disease, and who also have at least one of the other high-risk factors for developing CI-AKI.

Serum creatinine role in predicting outcome after cardiac surgery beyond acute kidney injury

Serum creatinine is still the most important determinant in the assessment of perioperative renal function and in the prediction of adverse outcome in cardiac surgery. Many biomarkers have been studied to date; still, there is no surrogate for serum creatinine measurement in clinical practice because it is feasible and inexpensive. High levels of serum creatinine and its equivalents have been the most important preoperative risk factor for postoperative renal injury. Moreover, creatinine is the mainstay in predicting risk models and risk factor reduction has enhanced its importance in outcome prediction. The future perspective is the development of new definitions and novel tools for the early diagnosis of acute kidney injury largely based on serum creatinine and a panel of novel biomarkers.