Abstract: Objective To examine the association of B-type natriuretic peptide with net ultrafiltration rate and net ultrafiltration in AKI patients with CRRT. Methods A total of 37 AKI patients with CRRT from August 2010 to April 2012 in Qingdao Municipal Hospital was enrolled in the retrospective study. Systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, heart rate, weight, Cr, BUN, albumin, hemoglobin, BNP, blood flow rate, replacement rate, duration of CRRT, net ultrafiltration rate and net ultrafiltration were recorded. Influencing factors of net ultrafiltration rate and net ultrafiltration were analyzed by Pearson/Spearman correlation. Predicting value of BNP in net ultrafiltration rate and net ultrafiltration was investigated by ROC curve. Results The top 3 reasons of our study patients for CRRT were oliguria/anuria (n=15, 40.5%), fluid retention (n=8,21.6%) and high urea/creatinine (n=8,21.6%). Hypotension related to CRRT occurred in 4 patients (10.8%). Serum creatinine was negatively correlated with net ultrafiltration rate (r=-0.331，P=0.045), and BNP positively correlated with net ultrafiltration rate (r=0.503，P=0.002). BNP (r=0.503，P=0.002) and duration of CRRT (r=0.759，P＜0.001) were positively correlated with net ultrafiltration respectively. In predicting net ultrafiltration rate ＞100ml/h, area under ROC curve of serum creatinine and BNP was 0.327 and 0.750 respectively. In predicting net ultrafiltration ＞1000ml, AUC of BNP and duration of CRRT was 0.824 and 0.867 respectively. In predicting hypotension related to CRRT, AUC of BNP, net ultrafiltration rate and net ultrafiltration was 0.977, 0.845 and 0.947 respectively. Conclusion The levels of BNP in AKI patients with CRRT were positively correlated with net ultrafiltration rate and net ultrafiltration. Net ultrafiltration rate and net ultrafiltration could be set according to the levels of BNP when CRRT initiates. It would maybe avoid or lessen hypotension related to CRRT in AKI patients.

Key words: Continuous renal replacement therapy, Acute kidney injury, B-type natriuretic peptide