Predictive value of cystatin C for the identification of illness severity in adult patients in a mixed intensive care unit

Divergence between serum creatine and cystatin C in estimating glomerular filtration rate of critically ill COVID-19 patients

Background

The clinical use of serum creatine (sCr) and cystatin C (CysC) in kidney function evaluation of critically ill patients has been in continuous discussion. The difference between estimated glomerular filtration rate calculated by sCr (eGFRcr) and CysC (eGFRcysc) of critically ill COVID-19 patients were investigated in this study.

Methods

This is a retrospective, single-center study of critically ill patients with COVID-19 admitted in intensive care unit (ICU) at Wuhan, China. Control cases were moderate COVID-19 patients matched in age and sex at a ratio of 1:1. The eGFRcr and eGFRcysc were compared. The association between eGFR and death were analyzed in critically ill cases. The potential factors influencing the divergence between eGFRcr and eGFRcysc were explored.

Results

A total of 76 critically ill COVID-19 patients were concluded. The mean age was 64.5 ± 9.3 years. The eGFRcr (85.45 (IQR 60.58–99.23) ml/min/1.73m²) were much higher than eGFRcysc (60.6 (IQR 34.75–79.06) ml/min/1.73m²) at ICU admission. About 50 % of them showed eGFRcysc < 60 ml/min/1.73 m² while 25% showed eGFRcr < 60 ml/min/1.73 m² (χ² = 10.133, p = 0.001). This divergence was not observed in moderate group. The potential factors influencing the divergence included serum interleukin-6 (IL-6), tumor necrosis factor (TNF-α) level as well as APACHEII, SOFA scores. Reduced eGFRcr (<60 mL/min/1.73 m²) was associated with death (HR = 1.939, 95%CI 1.078–3.489, p = 0.027).

Conclusions

The eGFRcr was generally higher than eGFRcysc in critically ill COVID-19 cases with severe inflammatory state. The divergence might be affected by inflammatory condition and illness severity. Reduced eGFRcr predicted in-hospital death. In these patients, we advocate for caution when using eGFRcysc.

The role of the BUN/albumin ratio in predicting mortality in COVID-19 patients in the emergency department

Introduction

Due to the high mortality and spread rates of coronavirus disease 2019 (COVID-19), there are currently serious challenges in emergency department management. As such, we investigated whether the blood urea nitrogen (BUN)/albumin ratio (BAR) predicts mortality in the COVID-19 patients in the emergency department.

Methods

A total of 602 COVID-19 patients who were brought to the emergency department within the period from March to September 2020 were included in the study. The BUN level, albumin level, BAR, age, gender, and in-hospital mortality status of the patients were recorded. The patients were grouped by in-hospital mortality. Statistical comparison was conducted between the groups.

Results

Of the patients who were included in the study, 312(51.8%) were male, and their median age was 63 years (49–73). There was in-hospital mortality in 96(15.9%) patients. The median BUN and BAR values of the patients in the non-survivor group were significantly higher than those in the survivor group (BUN: 24.76 [17.38–38.31] and 14.43 [10.84–20.42], respectively [p < 0.001]; BAR: 6.7 [4.7–10.1] and 3.4 [2.5–5.2], respectively [p < 0.001]). The mean albumin value in the non-survivor group was significantly lower than that in the survivor group (3.60 ± 0.58 and 4.13 ± 0.51, respectively; p < 0.001). The area-under-the-curve (AUC) and odds ratio values obtained by BAR to predict in-hospital COVID-19 mortality were higher than the values obtained by BUN and albumin (AUC of BAR, BUN, and albumin: 0.809, 0.771, and 0.765, respectively; odds ratio of BAR>3.9, BUN>16.05, and albumin<4.01: 10.448, 7.048, and 6.482, respectively).

Conclusion

The BUN, albumin, and BAR levels were found to be reliable predictors of in-hospital mortality in COVID-19 patients, but BAR was found to be a more reliable predictor than the BUN and albumin levels.

Silymarin protects against radiocontrast-induced nephropathy in mice

Silymarin, an extract from Silybum marianum (milk thistle) containing a standardized mixture of flavonolignans that ameliorates some types of liver disease and, more recently, kidney damage, could be used for the ROS-scavenging effect of these antioxidants. Furthermore, contrast-induced nephropathy (CIN) is an iatrogenic impairment of renal function in patients subjected to angiographic procedures for which there is not yet a successful preventative treatment. Recent evidence has shown that this event is related to tubular/vascular injury activated mainly by oxidative stress. However, whether this bioavailable and pharmacologically safe extract protects against CIN is not clear. We proposed to evaluate the possible protective role of the antioxidant silymarin in an experimental model of CIN. Adult male Swiss mice were separated into 6 groups and pretreated orally with silymarin (50, 200 and 300 mg/kg), N-acetylcysteine (200 mg/kg) or vehicle for 5 days before the CIN and control groups. Renal function was analyzed by plasma creatinine, urea and cystatin C levels. Additionally, blood reactive oxygen species (ROS) were evaluated using ROS bioavailability, protein oxidation and DNA damage. Renal oxidative damage was evaluated using apoptosis/cell viability assays and histological analysis. We showed that silymarin preserved renal function and decreased systemic and renal oxidative damage (antigenotoxic and antiapoptotic properties, respectively) in a dose-dependent manner and was superior to conventional treatment with N-acetylcysteine. Histologically, silymarin treatment also had beneficial effects on renal glomerular and tubular injuries. Therefore, silymarin prophylaxis may be an interesting strategy for the prevention of CIN.

Low TT4 as a predictor of poor outcomes in severe encephalitis: a multivariate analysis of 94 patients

BACKGROUND

To investigate the prognostic value of acute thyroid function in patients with severe encephalitis.

METHODS

We retrospectively analyzed information from patients with severe encephalitis from June 2012 to June 2017. Using multivariate logistic regression analysis, we examined predictors of poor outcomes in these patients after 6 months.

RESULTS

A total of 94 patients with severe encephalitis were included in the study. Univariate analysis showed that patients with good or poor outcomes had significantly different total thyroxine (TT4) (P = 0.012) and free triiodothyronine (FT3) (P = 0.049) levels, mechanical ventilation requirements (P < 0.001), pulmonary infection complications (P = 0.001), lengths of neurological intensive care unit (P = 0.003) and total hospital (P = 0.012) stay, and Acute Physiology and Chronic Health Evaluation (APACHE II) (P = 0.005) and Glasgow Coma Scale (GCS) (P = 0) scores. The results of multivariate analysis suggested the following factors to be associated with a poor outcome: a low TT4 level (OR 0.303, 95% CI 0.100-0.923) and a low GCS score (OR 0.683, 95% CI 0.506-0.923).

CONCLUSIONS

Low TT4 has a predictive value for the adverse outcomes of severe encephalitis; further study is needed for verification.

Blood Urea Nitrogen (BUN) is independently associated with mortality in critically ill patients admitted to ICU

PURPOSE

Blood urea nitrogen (BUN) was reported to be associated with mortality in heart failure patients. We aimed to evaluate admission BUN concentration in a heterogeneous critically ill patient collective admitted to an intensive care unit (ICU) for prognostic relevance.

METHODS

A total of 4176 medical patients (67±13 years) admitted to a German ICU between 2004 and 2009 were included. Follow-up of patients was performed retrospectively between May 2013 and November 2013. Association of admission BUN and both intra-hospital and long-term mortality were investigated by Cox regression. An optimal cut-off was calculated by means of the Youden-Index.

RESULTS

Patients with higher admission BUN concentration were older, clinically sicker and had more pronounced laboratory signs of multi-organ failure including kidney failure. Admission BUN was associated with adverse long-term mortality (HR 1.013; 95%CI 1.012-1.014; p<0.001). An optimal cut-off was calculated at 28 mg/dL which was associated with adverse outcome even after correction for APACHE2 (HR 1.89; 95%CI 1.59-2.26; p<0.001), SAPS2 (HR 1.85; 95%CI 1.55-2.21; p<0.001) and several parameters including creatinine in an integrative model (HR 3.34; 95%CI 2.89-3.86; p<0.001). We matched 614 patients with admission BUN >28 mg/dL to case-controls ≤ 28mg/dL corrected for APACHE2 scores: BUN above 28 mg/dL remained associated with adverse outcome in a paired analysis with the difference being 5.85% (95%CI 1.23-10.47%; p = 0.02).

CONCLUSIONS

High BUN concentration at admission was robustly associated with adverse outcome in critically ill patients admitted to an ICU, even after correction for co-founders including renal failure. BUN might constitute an independent, easily available and important parameter for risk stratification in the critically ill.