A Cochrane review included 19 studies (11 prevention, 8 treatment) with a total of 1861 subjects. Prevention: There was no difference in mortality between atrial natriuretic peptide (ANP) and control in either the low (RR 0.69, 95% CI 0.21 to 2.23; 10 studies, n=794) or high dose prevention studies. Low (but not high) dose ANP was associated with a reduced need for renal replacement therapy (RRT) in the prevention studies (RR 0.32, 95% CI 0.14 to 0.71; 10 studies, n=794). Length of hospital (MD -9.50 days, 95%CI -14.99 to -4.02; 3 studies, n=201) and ICU stay were significantly shorter in the low dose ANP group. Treatment: For established AKI, there was no difference in mortality with either low (RR 0.78, 95% CI 0.41 to 1.49; 6 studies, n=290) or high dose ANP (RR 1.09, 95% CI 0.91 to 1.29; 3 studies, n=813 participants). Low (but not high) dose ANP was associated with a reduction in the need for RRT (RR 0.54, 95% CI 0.30 to 0.98; 6 studies, n= 290). High dose ANP was associated with more adverse events (hypotension, arrhythmias).
After major surgery there was a significant reduction in RRT requirement with ANP in the prevention studies (RR 0.56, 95% CI 0.32 to 0.99; 9 studies, n= 551), but not in the treatment studies (RR 0.55, 95% CI 0.22 to 1.41; 5 studies, n=266). There was no difference in mortality between ANP and control in either the prevention or treatment studies. There was a reduced need for RRT with low dose ANP in patients undergoing cardiovascular surgery (RR 0.35, 95% CI 0.18 to 0.70; 8 studies, n= 493). ANP was not associated with outcome improvement in either radiocontrast nephropathy or oliguric AKI.
Comment: The quality of evidence is downgraded by study quality (inadequate or unclear allocation concealment) and by potential reporting bias.