Contrast-induced nephropathy in critical care

Side effects of radiographic contrast media: pathogenesis, risk factors, and prevention

Radiocontrast media (RCM) are medical drugs used to improve the visibility of internal organs and structures in X-ray based imaging techniques. They may have side effects ranging from itching to a life-threatening emergency, known as contrast-induced nephropathy (CIN). We define CIN as acute renal failure occurring within 24-72 hrs of exposure to RCM that cannot be attributed to other causes. It usually occurs in patients with preexisting renal impairment and diabetes. The mechanisms underlying CIN include reduction in medullary blood flow leading to hypoxia and direct tubule cell damage and the formation of reactive oxygen species. Identification of patients at high risk for CIN is important. We have reviewed the risk factors and procedures for prevention, providing a long list of references enabling readers a deep evaluation of them both. The first rule to follow in patients at risk of CIN undergoing radiographic procedure is monitoring renal function by measuring serum creatinine and calculating the eGFR before and once daily for 5 days after the procedure. It is advised to discontinue potentially nephrotoxic medications, to choose radiocontrast media at lowest dosage, and to encourage oral or intravenous hydration. In high-risk patients N-acetylcysteine may also be given.

Nephrotoxicity Of Polymyxin B: Experimental Study In Cells And Implications For Nursing Practice

The aim of the study was to characterize the cell damage mechanisms involved in the pathophysiology of cytotoxicity of polymyxin B in proximal tubular cells (LLC - PK1) and discuss about the nurses interventions to identify at risk patients and consider prevention or treatment of nephrotoxicity acute kidney injury. This is a quantitative experimental in vitro study, in which the cells were exposed to 375μM polymyxin B sulfate concentration. Cell viability was determined by exclusion of fluorescent dyes and morphological method with visualization of apoptotic bodies for fluorescence microscopy. Cells exposed to polymyxin B showed reduced viability, increased number of apoptotic cells and a higher concentration of the enzyme lactate dehydrogenase. The administration of polymyxin B in vitro showed the need for actions to minimize adverse effects such as nephrotoxicity.


Renoprotective effect of the Echinodorus macrophyllus in induced renal injury

OBJECTIVE: Evaluating the renoprotective effect of Echinodorus macrophyllusin acute kidney injury induced by cyclophosphamide in rats.METHODS: Experimental research with Wistar rats, male adults, distributed into groups, namely: Control - administration of 1.5 ml sodium chloride 0.9% intraperitoneally; Echinodorous - administration of 2g/kg of Echinodorus macrophyllus by gavage for five days; Cyclophosphamide - administration of cyclophosphamide 150mg/kg intraperitoneally; and Cyclosphosphamide + Echinodorus - administration of Echinodorus macrophyllus and cyclophosphamide. Renal function (creatinine clearance) and the oxidative metabolites (peroxides and urinary substances reactive to thiobarbituric acid, thiols in kidney tissue) were evaluated.RESULTS: Preconditioning with Echinodorus macrophyllus elevated the creatinine clearance and reduced the levels of oxidative metabolites.CONCLUSION: The antioxidant action of Echinodorus macrophyllus has demonstrated renoprotective effects evidenced by the reduction of oxidative stress in acute renal injury induced by cyclophosphamide in rats.

Contrast media induced nephropathy: a literature review of the available evidence and recommendations for practice

BACKGROUND

Contrast media induced nephropathy (CIN) is a sudden compromise of renal function 24-48 h after administering contrast medium during a CT scan or angiography. CIN accounts for 10% of hospital acquired renal failure and is ranked the third cause of acquiring this condition. Identifying patients at risk through proper screening can reduce the occurrence of this condition.

PURPOSE

This review paper aims to critique current evidence, provide a better understanding of CIN, inform nursing practice and make recommendations for bedside nurses and future research.

METHOD

An integrative review of the literature was made using the key terms: "contrast media", "nephritis", "nephropathy", "contrast media induced nephropathy scores", "acute kidney failure", "acute renal failure" and "acute kidney injury". MeSH key terms used in some databases were: "prevention and control", "acute kidney failure" and "treatment". Databases searched included Medline, CINAHL and Academic Search Complete, and references of relevant articles were also assessed. The search included all articles between the years 2000 and 2013.

RESULTS

Sixty-seven articles were obtained as a result of the search, including RCTs, systematic reviews, and retrospective studies.

CONCLUSION

Contrast media induced nephropathy is an iatrogenic complication occurring secondary to diagnostic or therapeutic procedures. At times it is unavoidable but a systematic method of risk assessment should be adopted to identify high risk patients for tailored and targeted approaches to management interventions.

CLINICAL IMPLICATIONS

As the use of contrast media is increasing for diagnostic purposes, it is important that nurses be aware of the risk factors for CIN, identify and monitor high risk patients to prevent deterioration in renal function when possible.