Post-coronarography application of continuous veno-venous hemofiltration in the prevention of contrast nephropathy in patients with complex multisystem deficiency.

BACKGROUND An increased admission of high-risk patients to diagnostic and interventional radiological procedures with contrast medium has resulted in an increase of contrast-induced nephropathy, which now represents the third main cause of hospital-acquired acute renal failure. The pathogenic mechanism of contrast-induced nephropathy (CN) is unclear, but there is much evidence which indicated an interaction between direct tubular cytotoxicity and osmotic/hemodynamic effects. Continuous veno-venous hemofiltration (CVVH) has shown possible benefits in preventing CN. It is not understood when and how prophylactic strategies should be used either in pharmacological therapies or in continous renal replacement therapy (CRRT) approaches. The aim of this study was to evaluate the efficiency of the CVVH technique in preventing CN secondary to emergency radiological procedures in very high-risk patients. PATIENTS AND METHODS Twelve patients with severe chronic renal impairment (serum creatinine concentration >2 mg/dl with an estimated glomerular filtration rate (eGFR) <40 ml/min) in association with at least two severe comorbidities (such as previous acute myocardial infarction in hypertensive or diabetic patients obesity, cardiac failure with ejection fraction <40%, severe hypotension) were treated with CVVH after coronarography using an iso-osmolar contrast medium (Visipaque, Iodixanol), with or without percutaneous transluminal coronary angioplasty. Adverse events and their association with the interventional radiological procedure were investigated after hemofiltration. RESULTS Statistically significant differences were observed for both eGFR and serum creatinine at different time points (pre-, post- and 7 days after the procedure) at p<0.05. Statistical analysis of all the variables related to the radiological procedure and the hemofiltration technique did not cause any modification of renal function between the pre- and post-procedure values. No patient showed signs of cardiovascular instability, nor were any episodes of marked hypotension reported during the dialysis session. No patient showed any adverse effects related to the interventional radiological procedure or to the CVVH technique. Renal function, according to serum creatinine concentration and the e-GFR calculation (Cockcroft), did not worsen but had improved when the patients left hospital, with function rates statistically significantly better compared to that on hospital admission, even 7 days after the radiological procedure. CONCLUSION The present study suggests the efficiency of the CVVH technique in preventing CN in high-risk patients who need to undergo interventional radiological cardiovascular procedures involving the administration of an iodine-based contrast medium.