ABSTRACT
BACKGROUND: The purpose of this study was to evaluate the prevalence of chronic kidney disease (CKD) and the incidence of perioperative acute kidney injury (AKI) in primary arthroplasty patients over 65 years of age. Risk factors, perioperative events and the outcome of surgery were evaluated. METHODS: This retrospective, hospital register-based study consists of patients operated in 2014 in the area of Oulu, Finland. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration formula. The incidence of AKI was evaluated based on the serum creatinine criteria of the KDIGO (Kidney Disease, Improving Global Outcomes) classification. RESULTS: Of the 807 patients, 60.8% had mildly decreased (60-89 ml/min/1.73 m2 ) and 13.5% moderately to severely decreased eGFR (<60 ml/min/1.73 m2 ) preoperatively. Only 33.9% of patients with an eGFR < 60 ml/min/1.73 m2 had a diagnosis of a kidney disease. In emergencies, 46.9% of patients with an eGFR < 60 ml/min/1.73 m2 were deceased at the 12-month follow-up point. The measurement of postoperative sCr was not complete (477/807) and was allocated to emergencies and older patient with more comorbidities. Of those whose postoperative sCr was available, 14 (2.9%) fulfilled AKI criteria. Most of the AKI cases had a decrease in eGFR preoperatively, a diagnosed kidney disease or diabetes mellitus. CONCLUSIONS: Impairment of kidney function was common and was related to mortality in emergency arthroplasties. Measurements of postoperative sCr were allocated to high risk patients. Preoperative kidney function, kidney disease and diabetes mellitus were important determinants for perioperative AKI.
Subject(s)
Acute Kidney Injury/etiology , Arthroplasty/adverse effects , Postoperative Complications/epidemiology , Renal Insufficiency, Chronic/etiology , Acute Kidney Injury/epidemiology , Aged , Aged, 80 and over , Creatinine/blood , Diabetes Complications/epidemiology , Emergency Medical Services , Female , Finland/epidemiology , Follow-Up Studies , Glomerular Filtration Rate , Humans , Kidney Function Tests , Male , Postoperative Complications/therapy , Renal Insufficiency, Chronic/epidemiology , Retrospective Studies , Risk Factors , Treatment OutcomeABSTRACT
We present a microwave correlation measurement system based on two low-cost USB-connected software defined radio dongles modified to operate as coherent receivers by using a common local oscillator. Existing software is used to obtain I/Q samples from both dongles simultaneously at a software tunable frequency. To achieve low noise, we introduce an easy low-noise solution for cryogenic amplification at 600-900 MHz based on single discrete HEMT with 21 dB gain and 7 K noise temperature. In addition, we discuss the quantization effects in a digital correlation measurement and determination of optimal integration time by applying Allan deviation analysis.
