The Incidence of Contrast Induced Nephropathy in Trauma Patients.

Abstract

PURPOSE: Contrast-induced nephropathy (CIN) has been recognized as a potential adverse outcome in patients receiving contrast dye for CT evaluation for over 50 years. Despite the time and resources dedicated to better identifying at-risk patients and implementing preventative measures, contrast induced nephropathy continues to be a significant cause of hospital acquired renal insufficiency. This study was aimed to evaluate the incidence and factors associated with contrast-induced nephropathy in the trauma patient population. MATERIALS AND METHODS: A retrospective institutional review of 563 patients admitted to the trauma service at St. Joseph’s Hospital and Medical Center were evaluated. Data were recorded for each patient including demographics, injury severity score (ISS), clinical prediction score (CPS), laboratory values on admission, 24, 48 and 72 hours including hematocrit, blood urea nitrogen, creatinine and eGFR, IV fluid volume given, contrast volume given, systolic blood pressure (SBP), urine output (UOP), intensive care unit length of stay (ICU LoS) and total hospital length of stay (tot LoS). Contrast induced nephropathy was considered to be present if the patient received contrast material for CT scan and 24-48 hour creatinine increased by an absolute value of 0.5mg/dl or if there was a 25% increase in 24-48 hour creatinine when compared to admission creatinine. Contrast volumes given to each patient before CT scan were determined by the Department of Radiology. RESULTS: As seen in table 1 results of univariate analysis demonstrate the following significant data: CIN vs age (p 0.004), CIN vs ISS (p <0.000), CIN vs CPS (p <0.000), CIN vs ICU length of stay (p 0.006), CIN vs total length of stay (p 0.002), CIN vs SBP (p <0.000), CIN vs IVF volume given in the 2nd 24 hours (p <0.000) and CIN vs IVF volume given in the first 48hrs (p <0.000). Data from multivariate analysis demonstrate the following significant data: CIN vs CPS (p <0.000, CI 1.92E-2 – 3.93E-2), CIN vs SBP (p 0.003 CI 8.61E-4 – 4.41E-3) and CIN vs IVF vol 2nd 24 hours (p 0.001, CI 1.47E-5 – 5.91E-5). The mean data for patients who did and did not develop CIN respectively were CPS: 9.09 and 3.12, SBP 84mmHg and 99mmHg, and IVF vol 2nd 24 hrs 2504ml and 5931ml CONCLUSION: Contrast induced nephropathy continues to be a significant problem in many hospital populations including trauma patients. Certain patient groups including those with higher CPS, hypotension or receiving decreased IV fluids may benefit from aggressive mindfulness of the risk of contrast induced kidney injury and continued investigation is needed to better identify trauma patients at increased risk.