Contrast-induced acute kidney injury and its contemporary prevention

The complexity and application range of interventional and diagnostic procedures using contrast media (CM) have recently increased. This allows more patients to undergo procedures that involve CM administration. However, the intrinsic CM toxicity leads to the risk of contrast-induced acute kidney injury (CI-AKI). At present, effective therapy of CI-AKI is rather limited. Effective prevention of CI-AKI therefore becomes crucially important. This review presents an in-depth discussion of CI-AKI incidence, pathogenesis, risk prediction, current preventive strategies, and novel treatment possibilities. The review also discusses the difference between CI-AKI incidence following intraarterial and intravenous CM administration. Factors contributing to the development of CI-AKI are considered in conjunction with the mechanism of acute kidney damage. The need for ultimate risk estimation and the prediction of CI-AKI is stressed. Possibilities of CI-AKI prevention is evaluated within the spectrum of existing preventive measures aimed at reducing kidney injury. In particular, the review discusses intravenous hydration regimes and pre-treatment with statins and N-acetylcysteine. The review further focuses on emerging alternative imaging technologies, alternative intravascular diagnostic and interventional procedures, and new methods for intravenous hydration guidance; it discusses the applicability of those techniques in complex procedures and their feasibility in current practise. We put emphasis on contemporary interventional cardiology imaging methods, with a brief discussion of CI-AKI in non-vascular and non-cardiologic imaging and interventional studies.

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

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

Can sodium fluorescein cause contrast-induced nephropathy?

BACKGROUND

Contrast-induced nephropathy (CIN) is a common cause of acute kidney injury (AKI), and can be diagnosed when the etiology of AKI is unclear other than via a contrast agent. Fluorescent angiography (FAG) with fluorescein sodium dye is generally considered to be safe for patients with kidney diseases. However, it remains unresolved whether or not FAG can induce CIN.

METHODS

Patients from two tertiary hospitals who underwent FAG and had serum creatinine results within 4 weeks before FAG and 3 days after FAG between 2001 and 2017 were retrieved. Cases with concurrent iodinated contrast imaging or undergoing dialysis were excluded from the analysis. CIN was defined by two criteria: CIN criteria as >0.5 mg/dL or >25% increase in serum creatinine (sCr) level within 3 days after FAG, and contrast-induced acute kidney injury (CIAKI) criteria as ≥0.3 mg/dL increase within 2 days or ≥50% increase within 7 days after FAG.

RESULTS

A total of 979 patients were screened, and we found 124 patients with AKI after FAG. After excluding 32 patients with clear causes of AKI other than FAG, the incidence rates of CIN were 7.3% by CIN criteria and 6.4% by CIAKI criteria. CIN incidence had a U-shaped distribution according to chronic kidney disease (CKD) stages in CIN criteria, while linear association between CIN incidence and CKD stages were found in CIAKI criteria. Kaplan-Meier curves showed the CIN group was significantly associated with end-stage renal disease (ESRD) progression (log-rank P < 0.001, in both CIN criteria and CIAKI criteria), and adjusted hazard ratios by multivariable Cox regression were 2.23 [95% confidence interval (CI) 1.468-3.378] in CIN criteria and 2.17 (95% CI 1.462-3.232) in CIAKI criteria.

CONCLUSIONS

According to CIN and CIAKI criteria, FAG may cause CIN and appeared to be a possible risk factor for ESRD progression. However, CIN or CIAKI criteria themselves may overestimate AKI and require meticulous attention to the interpretation of results.

Intravenous contrast use and acute kidney injury: a retrospective study of 1,238 inpatients undergoing computed tomography

OBJECTIVE

To determine the incidence of nephropathy induced by intravenous contrast in hospitalized patients undergoing computed tomography (CT).

MATERIALS AND METHODS

This was a retrospective cohort study involving 1,238 patients who underwent CT with or without intravenous administration of a contrast agent (iopromide). The primary outcome measure was acute kidney injury (AKI), as defined by the traditional criteria-an absolute or relative increase in serum creatinine (SCr) ≥ 0.5 mg/dL or ≥ 25% over baseline, respectively, at 2-3 days after contrast administration-and the newer, Kidney Disease: Improving Global Outcomes (KDIGO) criteria-an absolute or relative increase in SCr ≥ 0.3 mg/dL or ≥ 50% over baseline, respectively, at 2-7 days after contrast administration.

RESULTS

The overall incidence of AKI was 11.52% when the KDIGO criteria were applied. Univariate logistic regression demonstrated a significant association between an absolute post-CT increase in SCr ≥ 0.5 mg/dL and AKI, although that association did not retain significance in the multivariate analysis. Multivariate logistic regression initially found an association between an absolute post-CT increase in SCr ≥ 0.3 mg/dL and advanced age, although that association was not maintained after correction. We found no association between AKI and the risk factors evaluated.

CONCLUSION

We identified no criteria for contrast-induced nephropathy after CT; nor did we find AKI to be associated with the classical risk factors.

Incidence and Risk Factors of Postcontrast Acute Kidney Injury in Patients with Acute Ischemic Stroke

Background

Multimodal computed tomography (CT) guides decision-making regarding use of thrombolytic agents in acute ischemic stroke patients. However, postcontrast acute kidney injury (PC-AKI) is a potential adverse effect of the contrast media used, which may require hemodialysis and cause a longer hospital stay. The incidence and risk factors of PC-AKI in acute ischemic stroke patients, particularly in Thailand, remain unclear. Goal. We aimed at determining the incidence and risk factors of PC-AKI in patients with acute ischemic stroke undergoing multimodal CT.

Methods

We conducted a retrospective review of Thai acute ischemic stroke patients admitted to the King Chulalongkorn Memorial Hospital between January 2014 and December 2017 who received multimodal CT and thrombolytic treatment with alteplase.

Result

Overall, 109 patients were included for analysis; eight patients (7.3%) developed PC-AKI. Estimated glomerular filtration rate (eGFR) ≤ 30 mL/min and mechanical thrombectomy were risk factors significantly associated with PC-AKI.

Conclusion

The incidence of PC-AKI in a real practice setting did not differ from previous reports. Two factors were associated with PC-AKI, eGFR ≤ 30 mL/min and mechanical thrombectomy. Patients without these risk factors may not need to wait for the results of renal function testing prior to multimodal CT.