Place de la ponction biopsie rénale dans l'insuffisance rénale aiguë en réanimation

Acute renal failure (ARF) in intensive care unit patients is mostly due to ischemic acute tubular necrosis. ARF may have numerous other etiologies and the timely institution of the appropriate treatment for some causes may preserve renal function and improve outcome. The role of renal biopsy (RB) in the diagnosis and prognosis of ARF is debated and only few data have been published on this topic in ICU patients. RB is unnecessary when ARF is due to urinary tract obstruction, to vascular obstruction, and to acute tubular necrosis. The use of RB in the early phase of ARF is usually considered in patients with extrarenal manifestations suggesting the possibility of a systemic disease, in patients with a clinical evaluation and biological findings suggesting a glomerulonephritis, an acute interstitial nephritis or a microangiopathy, and in the absence of an obvious cause of ARF. The contraindications to RB included uncontrolled hypertension, cysts and tumors in the kidney, renal artery aneurysm, uncontrolled hemorrhagic diathesis, single or malformative kidney, perinephric abcess, and pyonephrosis. The precautions in performing RB included correcting arterial hypertension, normalizing coagulation and keeping hematocrit over 30%. The technique of RB in ICU patients is quite similar to the standard procedure and use of 18-gauge automated needle with real time ultrasonography guidance is recommended, making the procedure safer. Following the biopsy, blood pressure and pulse rates should be monitored and urines samples should be checked for possible macroscopic hematuria. The patient hematocrit should be checked 6 hours and then 24 hours after biopsy. In patients with contraindications open renal biopsy is a safer procedure. Recently, the transjugular renal biopsy technique was reported to be a relatively safe, reliable and minimally invasive procedure with an excellent diagnostic yield in high risk patients.