ED patients do NOT require<unk>  measurement<unk>  to IV<unk> :
If the study is immediately necessary to prevent life-threatening decompensation or delay in emergent treatment (e.g. trauma patients)
If they do not meet any of the following criteria:
Age >60
History of kidney disease
Kidney transplant
Dialysis
Single kidney
Renal cancer
Kidney surgery
Family history of kidney failure
Diabetes
Hypertension
Collagen vascular disease (e.g. SLE, scleroderma, rheumatoid arthritis)
Paraproteinemia (e.g. multiple myeloma)
Recent use of nephrotoxic medication (eg, metformin, aminoglycosides)
Age >60
History of kidney disease
Kidney transplant
Dialysis
Single kidney
Renal cancer
Kidney surgery
Family history of kidney failure
Diabetes
Hypertension
Collagen vascular disease (e.g. SLE, scleroderma, rheumatoid arthritis)
Paraproteinemia (e.g. multiple myeloma)
Recent use of nephrotoxic medication (eg, metformin, aminoglycosides)
Kidney transplant
Dialysis
Single kidney
Renal cancer
Kidney surgery
Creatinine screening prior to IV contrast
Thrombolytics for pulmonary embolism
Formal echocardiography
Balloon tamponade for massive GI bleeding
Renal ultrasound
Thrombolytics for STEMI
Thromboelastography 
Oral contrast for abdominal and pelvic CT