Determinants of outcome in non-septic critically ill patients with acute kidney injury on continuous venovenous hemofiltration.

Background/aims: In view of ongoing controversy, we wished to study whether patient characteristics and/or continuous venovenous hemofiltration (CVVH) characteristics contribute to the outcome of non-septic critically ill patients with acute kidney injury (AKI).

Methods: We retrospectively studied 102 consecutive patients in the intensive care unit (ICU) with non-septic AKI needing CVVH. Patient and CVVH characteristics were evaluated. Primary outcome was mortality up to day 28 after CVVH initiation.

Results: Forty-four patients (43%) died during the 28-day period after the start of CVVH. In univariate analyses, non-survivors had more often a cardiovascular reason for ICU admission, greater disease acuity/severity and organ failure, lower initial creatinine levels, less use of heparin and more use of bicarbonate-based substitution fluid. The latter two can be attributed to high lactate levels and bleeding tendency in non-survivors necessitating withholding lactate-buffered fluid and heparin, respectively, according to our clinical protocol. In multivariate analyses, mortality was predicted by disease severity, use of bicarbonate-based fluids and lack of heparin, while initial creatinine and CVVH dose did not contribute.

Conclusion: The outcome of non-septic AKI in need of CVVH is more likely to be determined by underlying or concurrent, acute and severe disease rather than by CVVH characteristics, including timing and dose.