Urea-Creatinine Ratio (UCR) After Aneurysmal Subarachnoid Hemorrhage: Association of Protein Catabolism with Complication Rate and Outcome.

OBJECTIVE: The urea-creatinine ratio (UCR) has been proposed as potential biomarker for critical illness-associated catabolism. Its role in the context of aneurysmal subarachnoid hemorrhage (aSAH) remains to be elucidated, which was the aim of the present study. METHODS: We enrolled 66 patients with aSAH with normal renal function and 36 patients undergoing elective cardiac surgery as a control group for the effects of surgery. In patients with aSAH, the predictive or diagnostic value of early (day 0-2) and critical (day 5-7) UCRs was assessed with regard to delayed cerebral ischemia (DCI), DCI-related infarction, and clinical outcome after 12 months. RESULTS: Preoperatively, UCR was similar both groups. Within 2 days postoperatively, UCRs increased significantly in patients in the elective cardiac surgery group (P < 0.001) but decreased back to baseline on day 5-7 (P = 0.245), whereas UCRs in patients with aSAH increased to significantly greater levels on day 5-7 (P = 0.028). Greater early or critical UCRs were associated with poor clinical outcomes (P = 0.015) or DCI (P = 0.011), DCI-related infarction (P = 0.006), and poor clinical outcomes (P < 0.001) respectively. In multivariate analysis, there was an independent association between greater early UCRs and poor clinical outcomes (P = 0.026). CONCLUSIONS: In this exploratory study of UCR in the context of aSAH, greater early values were predictive for a poor clinical outcome after 12 months, whereas greater critical values were associated with DCI, DCI-related infarctions, and poor clinical outcomes. The clinical implications as well as the pathophysiologic relevance of protein catabolism should be explored further in the context of aSAH.

Time courses of urinary creatinine excretion, measured creatinine clearance and estimated glomerular filtration rate over 30 days of ICU admission.

PURPOSE: Baseline urinary creatinine excretion (UCE) is associated with ICU outcome, but its time course is not known. MATERIALS AND METHODS: We determined changes in UCE, plasma creatinine, measured creatinine clearance (mCC) and estimated glomerular filtration (eGFR) in patients with an ICU-stay ≥30d without acute kidney injury stage 3. The Cockcroft-Gault, MDRD (modification of diet in renal disease) and CKD-EPI (chronic kidney disease epidemiology collaboration) equations were used. RESULTS: In 248 patients with 5143 UCEs hospital mortality was 24%. Over 30d, UCE absolutely decreased in male survivors and non-survivors and female survivors and nonsurvivors by 0.19, 0.16, 0.10 and 0.05 mmol/d/d (all P < 0.001). Relative decreases in UCE were similar in all four groups: 1.3, 1.4, 1.2 and 0.9%/d respectively. Over 30d, mCC remained unchanged, but eGFR rose by 31% (CKD-EPI) and 73% (MDRD) and creatinine clearance estimated by Cockcroft-Gault by 59% (all P < 0.001). CONCLUSIONS: Over 1 month of ICU stay, UCE declined by ≥1%/d which may correspond to an equivalent decline in muscle mass. These rates of UCE decrease were similar in survivors, non-survivors, males and females underscoring the intransigent nature of this process. In contrast to measured creatinine clearance, estimates of eGFR progressively rose during ICU stay.

Elevated urea-to-creatinine ratio provides a biochemical signature of muscle catabolism and persistent critical illness after major trauma.

PURPOSE: Muscle wasting is common amongst patients with persistent critical illness and associated with increased urea production, but reduced creatinine production. We hypothesised that elevated urea:creatinine ratio would provide a biochemical signature of muscle catabolism and characterise prolonged intensive care (ICU) admissions after major trauma. METHODS: Using pre-specified hypotheses, we analysed two existing data sets of adults surviving ≥ 10 days following admission to ICU after major trauma. We analysed trauma-ICU admissions to the major trauma centre serving the North East London and Essex Trauma Network, with a verification cohort of trauma-ICU cases from the MIMIC-III database. We compared serum urea, creatinine, and urea:creatinine ratio (ratio of concentrations in mmol/L) between patients with persistent critical illness (defined as ICU stay of ≥ 10 days) and those discharged from ICU before day 10. In a sub-group undergoing sequential abdominal computerised tomography (CT), we measured change in cross-sectional muscle area (psoas muscle at L4 vertebral level and total muscle at L3 level) and assessed for relationships with urea:creatinine ratio and ICU stay. Results are provided as median [interquartile range]. RESULTS: We included 1173 patients between February 1st, 2012 and May 1st, 2016. In patients with ICU stay ≥ 10 days, day 10 urea:creatinine ratio had increased by 133% [72-215], from 62 [46-78] to 141 [114-178], p < 0.001; this rise was larger (p < 0.001) than in patients discharged from ICU before day 10, 59% [11-122%], 61 [45-75] to 97 [67-128], p < 0.001. A similar separation in trajectory of urea:creatinine ratio was observed in 2876 trauma-ICU admissions from MIMIC-III. In 107 patients undergoing serial CTs, decrease in L4 psoas and L3 muscle cross-sectional areas between CTs significantly correlated with time elapsed (R2 = 0.64 and R2 = 0.59, respectively). Rate of muscle decrease was significantly greater (p < 0.001 for interaction terms) in 53/107 patients with the second CT during evolving, current or recent persistent critical illness. In this group, at the second CT urea:creatinine ratio negatively correlated with L4 psoas and L3 muscle cross-sectional areas (R2 0.39, p < 0.001 and 0.44, p < 0.001). CONCLUSION: Elevated urea:creatinine ratio accompanies skeletal muscle wasting representing a biochemical signature of persistent critical illness after major trauma. If prospectively confirmed, urea:creatinine ratio is a potential surrogate of catabolism to examine in epidemiological and interventional studies.

Dehydration Status Predicts Short-Term and Long-Term Outcomes in Patients with Cerebral Venous Thrombosis.

BACKGROUND: Dehydration is associated with a higher risk of poor outcome and venous thromboembolism in acute ischemic stroke patients. However, the relationship between dehydration and prognosis in patients with cerebral venous thrombosis (CVT) has not yet been investigated. METHODS: Consecutive CVT patients at the First Affiliated Hospital of Zhengzhou University were retrospectively identified from November 2011 through January 2017. Dehydration was evaluated by blood urea/creatinine (U/Cr) ratio > 80. Poor functional outcome was defined as modified Rankin Scale (mRS) of 3-6. Factors such as age, sex, coma, intracerebral hemorrhage, and straight sinus and/or deep CVT involved were adjusted to assess the relationship between dehydration, and prognosis at discharge and long-term follow-up in CVT patients. RESULTS: A total of 220 CVT patients were included, and 85 patients (38.64%) were dehydrated. Multivariate logistic regression analysis indicated that patients with dehydration had a higher risk of mRS of 3-6 at discharge (adjusted odds ratio [OR] 3.629, 95% confidence intervals [CI] 1.526-8.633, P = 0.004) and long-term outcome (adjusted OR 3.831, 95% CI 1.597-9.190, P = 0.003). Subgroup analysis stratified by potential factors that might be associated with dehydration, such as infection, vomiting, pregnancy, and/or postpartum, showed similar results. Multivariate Cox regression analysis further demonstrated that dehydration was associated with higher mortality (adjusted hazard ratio [HR] = 2.301, 95% CI 1.025-5.166, P = 0.043). CONCLUSIONS: The present findings indicate that dehydration is an independent predictor for short-term and long-term unfavorable functional outcome in patients with CVT.

Diagnostic performance of serum blood urea nitrogen to creatinine ratio for distinguishing prerenal from intrinsic acute kidney injury in the emergency department.

BACKGROUND: The blood urea nitrogen to creatinine ratio (BCR) has been used since the early 1940s to help clinicians differentiate between prerenal acute kidney injury (PR AKI) and intrinsic AKI (I AKI). This ratio is simple to use and often put forward as a reliable diagnostic tool even though little scientific evidence supports this. The aim of this study was to determine whether BCR is a reliable tool for distinguishing PR AKI from I AKI. METHODS: We conducted a retrospective observational study over a 13 months period, in the Emergency Department (ED) of Nantes University Hospital. Eligible for inclusion were all adult patients consecutively admitted to the ED with a creatinine >133 µmol/L (1.5 mg/dL). RESULTS: Sixty thousand one hundred sixty patients were consecutively admitted to the ED. 2756 patients had plasma creatinine levels in excess of 133 µmol/L, 1653 were excluded, leaving 1103 patients for definitive inclusion. Mean age was 75.7 ± 14.8 years old, 498 (45%) patients had PR AKI and 605 (55%) I AKI. BCR was 90.55 ± 39.32 and 91.29 ± 39.79 in PR AKI and I AKI groups respectively. There was no statistical difference between mean BCR of the PR AKI and I AKI groups, p = 0.758. The area under the ROC curve was 0.5 indicating that BCR had no capacity to discriminate between PR AKI and I AKI. CONCLUSIONS: Our study is the largest to investigate the diagnostic performance of BCR. BCR is not a reliable parameter for distinguishing prerenal AKI from intrinsic AKI.

Urea to creatinine ratio: a forgotten marker of poor nutritional state in patients undergoing hemodialysis treatment.

BACKGROUND: Malnutrition is common in subjects undergoing hemodialysis and is associated with increased morbidity and mortality. Studies investigating factors associated with malnutrition and effect of various interventions to treat these patients are needed. We aimed to screen older and young patients undergoing chronic hemodialysis, for malnutrition, and seek its association with clinical factors including anxiety and depression and laboratory variables including urea/creatinine ratio (UCR). METHODS: Duration of hemodialysis treatment, medications taken, anthropometric measurements and routine laboratory results were recorded. Mini nutritional assessment and Beck anxiety and Beck depression inventories were applied. Study variables between subjects with malnutrition, malnutrition risk and normal nutritional states were compared. Older and younger patients were also compared regarding malnutrition and laboratory results. Linear regression analysis was performed to seek independent factors associated with malnutrition score. RESULTS: Clinical and laboratory data except for UCR were found to be similar among young and older patients. UCR increased, while albumin, body mass index and weight circumference decreased along with worse nutritional state. Low albumin level, body mass index and UCR and higher hemoglobin level and depression score were independent factors associated with malnutrition. CONCLUSION: In addition to routinely used markers of malnutrition UCR may provide additional information regarding malnutrition in this population.