Kidney biopsy in the critically ill patient, results of a multicentre retrospective case series.

Background: The impact of a contributive result of kidney biopsy on the management of patients in the intensive care unit (ICU) has not been extensively investigated yet.

Methods: This was a retrospective study conducted between 2000 and 2011 in five French ICUs. The study included 56 patients. They had at least one non-renal organ failure, as defined by a Sequential Organ Failure Assessment (SOFA) score ≥3 on ICU admission, and kidney biopsy was performed during ICU stay. Kidney samples were obtained by percutaneous (N.=55) or transjugular biopsy (N.=1).

Results: The mean Simplified Acute Physiology Score II and total SOFA scores on ICU admission were 52±19 years and 10.3±3.6, respectively. ICU mortality was 23%. The median (interquartile range) time between ICU admission and kidney biopsy was 9 days (5-21). Pathologic findings in the 54 analyzable kidney biopsies were acute tubular necrosis (N.=26), glomerulonephritis (N.=14), acute vascular nephritis (N.=11), acute interstitial nephritis (N.=6), and deposit disease (N.=3). Kidney biopsy was contributive to the management of 40 patients. In 23 of these, new treatments were started, in 13 ongoing treatments were stopped, including four life-sustaining therapies, and in 13 it was decided to start chronic renal replacement. Severe bleeding was observed in 7 patients, with fatal outcome in one case.

Conclusion: Kidney biopsy may have a significant impact on the management of critically ill patients. Further studies should be done to identify the groups of ICU patients likely to benefit from the procedure with minimum risk.