Pilot Study Of Bedside Ultrasound For The Assessment Value Of Acute Kidney Injury In Major Trauma Patients

Objective:The objective of this study was to test bedside ultrasound for the assessment of acute kidney injury in major trauma patients.Methods:This was a prospective observational study in emergency intensive care unit(EICU) in a teaching university hospital. From December 2013 to February 2014, a total of 44 major trauma patients were enrolled.Measurements of hemodynamic parameters, Doppler-based RRI and Power Doppler ultrasound (PDU) score were obtained at the first 7 days from admission to the EICU. Injury severity score(ISS), Acute Physiology and Chronic Health Evaluation system II, Glasgow coma score(GCS), ICU length of stay(LOS), the duration of ventilator support were recorded. CystatinC (Cys C) andβ2-microglobulin(β2-MG) were tested at 1st,3rd,5th,7th day after admission to the EICU. All patients divided into AKI group and no-AKI group. Comparing the difference between the two groups about the above indicators. We drew the receiver operating characteristic (ROC) curves of RRI, Cys C, β2-MG to judge AKI and determined the best critical points to judge AKI at the first 7 days from admission to the EICU, then compared their areas under the curves by z test. The indices correlated significantly with RRI were filtrated by stepwise linear regression analysis.Results:Among 44 patients, there were 8 patients in AKI group and 36 patients in no-AKI group.Patients in AKI group had higher RRI than those in no-AKI group.The areas under the ROC curves of RRI to judge AKI were 0.731±0.134、0.773±0.121、 0.843±0.075,0.808±0.118,0.769±0.114.0.840±0.121.0.811±0.118 separately at the first 7 days from admission to the EICU, and they were all more than 0.5 significantly. There were no significant differences among them. There were also no significant differences among the areas under the ROC curves of RRI, Cys C, β2-MG to judge AKI. Age and AKI stage correlated significantly with RRI at the first 7 days from admission to the EICU. Mean arterial pressure, hear rate, arterial partial pressure of oxygen and pulse pressure correlated significantly with RRI at some days.Conclusion:Doppler-based RRI correlated significantly with AKI in major trauma patients, and reflected AKI severity to some extend. Doppler-based RRI can be used as a beneficial supplement of routine kidney function evaluation method.