However, neither low clearance nor absorption resulted in net removal of NGAL during CVVH, so that we cannot formally meantime exclude concomitant production, for instance via release by activated neutrophils. Moreover, any production in the filter could be offset by adsorption. We cannot judge on the inhibitory effect of citrate on neutrophil activation in this respect, since in fact we did not observe net production of NGAL in the filter in any of the anticoagulation groups. Concentrations of NGAL in the ultrafiltrate were lowest in the citrate group, but this could partly be explained by dilution due to higher ultrafiltration rates. Dissimilar degranulation patterns of primary and secondary granules of neutrophils might account for the absence of NGAL release in the filter, since primary granular markers elastase and myeloperoxidase are released during heparin CVVH whereas secondary granular NGAL apparently is not.

Indeed, others observed that there was lower release of lactoferrin, a secondary granular product similar to NGAL, than of MPO during citrate based dialysis. The limitations of the present study include the relatively small size of groups and the absence in part of randomisation, explaining some baseline differences Inhibitors,Modulators,Libraries among the groups. Patients in the no anticoagulation group did not receive anticoagulation Inhibitors,Modulators,Libraries because of a bleeding tendency and, indeed, were more severely ill demonstrated by higher Inhibitors,Modulators,Libraries SAPS II and SOFA scores at baseline and lower platelet counts. We cannot exclude earlier start of CVVH in the no anticoagulation group than in the other groups, since initial creatinine was lower, but this does not invalidate our conclusions of this pathophysiologic study.

We have evaluated the course of study variables for up to 12 hours during Inhibitors,Modulators,Libraries a single filter run only and do not exclude changes beyond that time interval or subsequent CVVH runs. Conclusions Inhibitors,Modulators,Libraries In conclusion, the biomarker value of NGAL in critically ill patients with AKI are not affected by CVVH, since clearance by the filter was low. Therefore, plasma levels of NGAL may be utilized for prognostication in patients receiving CVVH. Furthermore, there is probably no intrafilter release of NGAL by neutrophils, irrespectively of the anticoagulation method applied.

Key messages Plasma levels of NGAL in critically ill patients with acute kidney injury correlate with disease severity at initiation of CVVH promotion information and at the end of the a CVVH run There is no net removal of NGAL during CVVH and therefore plasma levels of NGAL may be utilized for prognostication There is no evidence for production of NGAL in the filter by neutrophils irrespective of the type of anticoagulation applied Introduction Clinical Practice Guidelines on nutrition therapy in the Intensive Care Unit have been published to help clinicians make decisions regarding feeding their critically ill patients.