Use of a urine dipstick and brief clinical questionnaire to predict an abnormal serum creatinine in the emergency department.

OBJECTIVES Prior data demonstrated that a urine dipstick used alone was a sensitive predictor of abnormal creatinine, but not sufficiently enough to forego screening of serum creatinine prior to administration of contrast for diagnostic studies. The authors hypothesized that a brief historical questionnaire coupled with a urine dipstick would have high sensitivity for renal dysfunction, potentially eliminating the need for a serum creatinine prior to contrast administration. METHODS This was a prospective study of a convenience sample of patients at two academic tertiary-care emergency departments (EDs) during 2006-2007. Subjects included patients who had both a serum creatinine result reported by the laboratory and a urine dipstick result reported in the medical record. Data included triage vital signs, basic demographic data, 14 medical history items, dipstick urinalysis, and serum creatinine results. The main outcome measure was an abnormal serum creatinine, defined as greater than 1.5 mg/dL. RESULTS Complete data sets were collected on 1,354 patient visits. Of these, there were 161 (12%) with a serum creatinine of >1.5 mg/dL. Logistic regression analysis identified the following independent predictors associated with elevated creatinine: age greater than 60 years, known renal insufficiency, diabetes, hypertension, diuretic use, vomiting, and proteinuria. Nearly all patients with abnormal creatinine (98%) had at least one of these seven predictors. A decision tool combining these predictors would have identified 158 of 161 patients with an abnormal creatinine (sensitivity, 98.1%; 95% confidence interval [CI] = 95.8% to 99.9%) and a specificity of 21.2% (95% CI = 18.8% to 23.2%). CONCLUSIONS The absence of six historical factors and absence of proteinuria can be safely used to identify patients who are unlikely to have an abnormal creatinine.

[1]  Theodore C Chan,et al.  The impact of a pneumatic tube and computerized physician order management on laboratory turnaround time. , 2008, Annals of emergency medicine.

[2]  D. Davis,et al.  Can urine dipstick be used as a surrogate for serum creatinine in emergency department patients who undergo contrast studies? , 2007, The Journal of emergency medicine.

[3]  J. Hollander,et al.  Discordance between serum creatinine and creatinine clearance for identification of ED patients with abdominal pain at risk for contrast-induced nephropathy. , 2007, The American journal of emergency medicine.

[4]  Lawrence M Lewis,et al.  The impact of input and output factors on emergency department throughput. , 2007, Academic emergency medicine : official journal of the Society for Academic Emergency Medicine.

[5]  J. Kline,et al.  Contrast nephropathy following computed tomography angiography of the chest for pulmonary embolism in the emergency department , 2007, Journal of thrombosis and haemostasis : JTH.

[6]  J. Weinreb,et al.  IV contrast administration for CT: a survey of practices for the screening and prevention of contrast nephropathy. , 2006, AJR. American journal of roentgenology.

[7]  P. Aspelin,et al.  Contrast-Induced Nephropathy: A Clinical and Evidence-Based Approach , 2006, Circulation.

[8]  D. Richardson,et al.  Increase in patient mortality at 10 days associated with emergency department overcrowding , 2006, The Medical journal of Australia.

[9]  P. Parfrey The Clinical Epidemiology of Contrast-Induced Nephropathy , 2005, CardioVascular and Interventional Radiology.

[10]  S. Trzeciak,et al.  Clinical review: Emergency department overcrowding and the potential impact on the critically ill , 2004, Critical care.

[11]  J. Glauser,et al.  Urine protein as a rapid screen for renal function in the ED: can it replace serum creatinine in selected patients? , 2003, Emergency Radiology.

[12]  H. Clark,et al.  Serum creatinine is an inadequate screening test for renal failure in elderly patients. , 2003, Archives of internal medicine.

[13]  P. Choyke,et al.  Determination of serum creatinine prior to iodinated contrast media: is it necessary in all patients? , 1998, Techniques in urology.

[14]  J. Olsen,et al.  Utility of the creatinine prior to intravenous contrast studies in the emergency department. , 1996, The Journal of emergency medicine.

[15]  P. Choyke,et al.  Determination of Serum Creatinine Level Before Intravenous Administration of Iodinated Contrast Medium: A Survey , 1995, Investigative radiology.