[Physiopathology, clinical aspects and prevention of renal insufficiency caused by contrast media].
Contrast-media associated nephropathy (CMAN) consists in a sudden impairment of glomerular filtration rate following exposure to radiographic contrast materials. Damage may be limited to an asymptomatic mild increase of blood creatinine, or reach the highest levels of nitrogen retention compatible with acute renal failure. Some preexisting clinical conditions or pathologies may lead to CMAN: not only renal insufficiency, diabetes mellitus, multiple myeloma, congestive heart failure and severe hypertension, but also simple dehydration and a growing series of immunologic diseases are recognized as predisposing condition. The exact mechanism responsible for renal injury is still doubtful but recently animal models have shown substantial ischemic changes that may be added to the traditional presumed pathogenesis of direct tubular toxicity and intra-tubular obstruction. As renal ischemia stimulates both endogenous vasoconstrictor and vasodilator substances, it is now supposed that CMAN acts similarly to non-steroidal anti-inflammatory agents, selectively inhibiting the vasodilatory prostaglandin phase and therefore causing a derangement of the physiologic vasoconstriction/vasodilatation balance of renal circulation. The role of oxygen free radicals to contribute to renal dysfunction is considered. Low osmolality non ionic contrast media when compared to conventional high osmolality ionic contrast media have reduced but not eliminated CMAN. Simple but effective lines of prevention include the previous selection of patients predisposed to CMAN for concomitant pathology, suspension of FANS or any other recognized nephrotoxic substance, the least amount of contrast media compatible with radiologic visualization of the patient's problem, careful hydration of the patient before contrast injection and sustained diuresis afterwards. The usefulness of pre-treatment with Ca-channel blockers or atrial natriuretic factors remains sub judice.
Savazzi
G
G
Istituto di Clinica Medica e Nefrologia, Università, Parma.
Cusmano
F
F
Allegri
L
L
Garini
G
G
D058186:Acute Kidney Injury / Q000139:chemically induced / Q000175:diagnosis / Q000517:prevention & control; D003287:Contrast Media / Q000009:adverse effects*; D005609:Free Radicals; D006801:Humans; D007668:Kidney / Q000187:drug effects; D007674:Kidney Diseases / Q000139:chemically induced* / Q000175:diagnosis / Q000517:prevention & control; D007684:Kidney Tubules / Q000187:drug effects
D003287:Contrast Media; D005609:Free Radicals