Abstract
Objective: Generally, posttraumatic acute kidney injury (AKI) has a poor prognosis in elderly patients, but severe multiple trauma patients necessitates contrast computed tomography (CT) imaging without assessment of renal function. Therefore, injection of contrast media in elderly patients may compromise renal function. We assessed the risk factors of posttraumatic AKI and effect of using contrast media in elderly patients.
Methods: We investigated 130 patients who survived for over 48 hours after admission for trauma and underwent renal function assessment at the Tertiary Emergency Medical Center of Tokyo Metropolitan Bokutoh Hospital during the year 2010. We classified patients into 2 groups by the presence or absence of AKI (AKI and non-AKI groups) and investigated the relationship between the onset of AKI and the following factors: vital signs, blood parameters, injury severity score (ISS), revised trauma score, and probability of survival (Ps).
Results: Nineteen patients developed AKI; 16 of them received contrast enhanced CT or IVR. The age, sex, cause of trauma, and serum creatinine levels showed no significant intergroup difference. The AKI group had significantly lower levels of estimated Glomerular Filtration Rate (eGFR), higher fibrin degradation product, higher ISS, lower Ps, and higher mortality than the non-AKI group, but the groups showed no significant difference in the use of contrast media. Logistic regression analysis revealed that the onset of AKI was solely influenced by the ISS, heart rate and previous history of diabetes. Among the 16 patients with contrast-induced nephropathy, those whose serum creatinine levels showed transient changes had good prognosis, while those with continuously elevated levels had higher ISS and poor prognosis.
Conclusions: Our results show that contrast CT and interventional radiology for multiple trauma in elderly patients were not a significant risk factor of causing acute kidney injury. ISS, heart rate and previous history of diabetes were risk factors of posttraumatic AKI. A changing pattern of serum creatinine was significant predictor for prognosis of posttraumatic AKI patient.
