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

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.

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.

Post-Contrast Acute Kidney Injury and Intravenous Prophylactic Hydration: An Update

BACKGROUND

 Despite tremendous improvement in molecular properties over the last century, intravascular injection of iodinated contrast material may still have systemic and hemodynamic consequences. Patients with pre-existing renal insufficiency may be at risk for acute kidney injury, which may be associated with an increased risk of the need for dialysis and mortality in the long term. Many questions as to the physiological pathways, optimal definition, and incidence of contrast-induced acute kidney injury remain open. These uncertainties are reflected in the changing landscape of this field in terms of nomenclature, research, and clinical practice.

METHODS

 Clinical practice guidelines for the prevention of post-contrast acute kidney injury all recommend giving prophylaxis in the form of intravenous hydration to high-risk patients. Solid evidence for this strategy is lacking. This article gives an overview of the changing landscape of post-contrast acute kidney injury and prophylactic intravenous hydration, with the aim of supporting informed decision-making in clinical practice.

RESULTS

 Recent data have caused a shift in guideline recommendations: 90 % of patients formerly considered high-risk for contrast-induced acute kidney injury no longer qualify for prophylaxis. The remaining high-risk patients, with severe chronic kidney disease, represent a vulnerable population for whom intravenous hydration may provide some benefits but also carries risk.

CONCLUSION

 Intravenous hydration may benefit 'new' high-risk patients. However, it also confers risk. A dual approach to screening patients will help avoid this risk in clinical practice.

KEY POINTS

  · Intravenous hydration is the cornerstone for preventing contrast-induced acute kidney injury. · Solid evidence is lacking; recent data caused a shift in guideline recommendations. · Intravenous hydration may benefit 'new' high-risk patients with severe chronic kidney disease; however, it also confers risk. · A dual approach to screening patients will help avoid this risk in clinical practice.

CITATION FORMAT

· Nijssen E, Rennenberg R, Nelemans P et al. Post-Contrast Acute Kidney Injury and Intravenous Prophylactic Hydration: An Update. Fortschr Röntgenstr 2021; 193: 151 - 159.

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.

Contrast Nephropathy Associated with Percutaneous Coronary Angiography and Intervention

Contrast nephropathy (CN) is acute kidney injury (AKI) that occurs within 24 to 72 hours of iodinated contrast medium (ICM) administration. Mechanisms of CN include hyperviscosity, free radical formation, and renal medullary oxygen supply/demand mismatch. Although risk factors for CN have been identified, it remains uncertain whether ICM causes or is simply associated with AKI. The cornerstones of CN prevention are using low-osmolal ICM, intravenous hydration, and statins, especially in patients with chronic kidney disease. With appropriate CN risk mitigation, coronary angiography and intervention should not be routinely withheld from patients with acute coronary syndromes.

Prophylactic Intravenous Hydration to Protect Renal Function From Intravascular Iodinated Contrast Material (AMACING): Long-term Results of a Prospective, Randomised, Controlled Trial

BACKGROUND

The aim of A MAastricht Contrast-Induced Nephropathy Guideline (AMACING) trial was to evaluate non-inferiority of no prophylaxis compared to guideline-recommended prophylaxis in preventing contrast induced nephropathy (CIN), and to explore the effect on long-term post-contrast adverse outcomes. The current paper presents the long-term results.

METHODS

AMACING is a single-centre, randomised, parallel-group, open-label, phase 3, non-inferiority trial in patients with estimated glomerular filtration rate [eGFR] 30-59 mL/min/1.73 m2 combined with risk factors, undergoing elective procedures requiring intravenous or intra-arterial iodinated contrast material. Exclusion criteria were eGFR < 30 mL/min/1.73 m2, dialysis, no referral for prophylaxis. The outcomes dialysis, mortality, and change in renal function at 1 year post-contrast were secondary outcomes of the trial. Subgroup analyses were performed based on pre-defined stratification risk factors. AMACING is registered with ClinicalTrials.gov: NCT02106234.

FINDINGS

From 28,803 referrals, 1120 at-risk patients were identified. 660 consecutive patients agreed to participate and were randomly assigned (1:1) to no prophylaxis (n = 332) or standard prophylactic intravenous hydration (n = 328). Dialysis and mortality data were available for all patients. At 365 days post-contrast dialysis was recorded in two no prophylaxis (2/332, 0.60%), and two prophylaxis patients (2/328, 0.61%; p = 0.9909); mortality was recorded for 36/332 (10.84%) no prophylaxis, and 32/328 (9.76%) prophylaxis patients (p = 0.6490). The hazard ratio was 1.118 (no prophylaxis vs prophylaxis) for one-year risk of death (95% CI: 0.695 to 1.801, p = 0.6449). The differences in long-term changes in serum creatinine were small between groups, and gave no indication of a disadvantage for the no-prophylaxis group.

INTERPRETATION

Assuming optimal contrast administration, not giving prophylaxis to elective patients with eGFR 30-59 mL/min/1.73 m2 is safe, even in the long-term.

FUNDING

Stichting de Weijerhorst.

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.

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

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

Oral rehydration solution (OS-1) as a substitute of intravenous hydration after cisplatin administration in patients with lung cancer: a prospective multicenter trial

Background

The aim of this trial was to evaluate the safety and efficacy of oral hydration as a substitute for intravenous hydration after cisplatin (CDDP) administration.

Methods

The major eligibility criteria included patients with lung cancer, indications for a CDDP-based regimen at a dose of 60 mg/m² or higher, an age of between 20 and 74 years and adequate renal function. Antiemetic prophylaxis consisted of an appropriate dose of palonosetron, aprepitant, dexamethasone and magnesium sulfate (8 mEq). Five hundred millilitres of commercially available oral hydration solution (OS-1: Otsuka Pharmaceutical Factory, Tokushima, Japan) was used as a substitute for intravenous posthydration. The planned sample size was 46 to reject a proportion of 70% under an expectation of 88% with a power of 90% and an alpha error of 5%.

Results

Between May and November 2013, 31 men and 15 women with a median (range) age of 65 (33–74) years were enrolled from three institutions. Of these, five received adjuvant chemotherapy, 17 received definitive chemoradiotherapy and 24 received chemotherapy for advanced diseases. The median (range) number of chemotherapy cycles was 4 (1–5). After the first cycle of CDDP administration, none of the patients experienced a creatinine elevation of grade 2 or higher, thereby meeting the primary endpoint. Of the 46 patients, 45 (97.8%, 95% CI 88.2 to 99.9) completed the CDDP-based chemotherapy without grade 2 or higher renal dysfunction.

Conclusion

Oral hydration can be used as a safe and convenient substitute for intravenous posthydration for CDDP administration at the standard dose.

Trial registration number

UMIN000010201.