Are there instances when you would recommend obtaining a 24 hour urine protein measurement in place of spot urine protein studies in patients with acute kidney injury and proteinuria?   

I would look at the urinalysis and if there was dipstick proteinuria, I would get a spot protein creatinine ratio (PCR) and a simultaneous albumin creatinine ratio (ACR), just to get some idea if I am dealing with a glomerular or tubular cause of AKI. These tests are not reliable from a quantity sta...

I've been noting the ratio of urinary albumin to urinary protein for some time and found that 40% is a very useful threshold. Above that value, the proteinuria is likely to be glomerular. That 40% figure originally came from something I read some years ago, but can no longer put my finger on.