Utility of the blood urea nitrogen to serum albumin ratio as a prognostic factor of mortality in aspiration pneumonia patients

Blood urea nitrogen to serum albumin ratio as a new indicator of disease severity and prognosis in idiopathic pulmonary artery hypertension

BACKGROUND

Emerging evidence has shown that the blood urea nitrogen to serum albumin ratio (BAR) is associated with the severity and prognosis of heart failure. However, its role in idiopathic pulmonary arterial hypertension (IPAH) remains unclear. This study investigated the associations between BAR and functional status, echocardiographic findings, hemodynamics, and long-term outcomes among patients with IPAH.

METHODS

This study included consecutive patients who underwent right heart catheterization (RHC) and were diagnosed with IPAH between January 2013 and January 2018 at Fuwai Hospital. The primary outcome was the worsening of clinical symptoms. Spearman correlation coefficients were used to evaluate the association between the BAR and established markers of IPAH severity. Receiver operating characteristic (ROC) curve analysis was used to determine BAR's optimal cut-off and predictive performance. Kaplan-Meier analysis and Cox proportional hazard models assessed the relationship between BAR and clinical worsening.

RESULTS

A total of 340 patients with IPAH were included in this study. BAR correlated with well-validated variables that reflected the severity of IPAH, such as World Health Organization functional class, 6-min walk distance, N-terminal pro-brain natriuretic peptide (NT-proBNP) level, mixed venous oxygen saturation, and cardiac index. Kaplan-Meier curves indicated that patients with BAR＞3.80 had a significantly higher clinical worsening rate (log-rank test, P < 0.001) than those with BAR≤3.80. Multivariate Cox analysis showed that BAR could independently predict clinical worsening [hazard ratio(HR):2.642, 95 % confidence interval (CI):1.659-4.208, P < 0.001]. In addition, BAR provided additional predictive value for the European Society of Cardiology (ESC)/European Respiratory Society (ERS) risk assessment score.

CONCLUSIONS

BAR reflects disease severity and is independently associated with the prognosis of patients with IPAH.

Preoperative blood urea nitrogen-to-serum albumin ratio for prediction of in-hospital mortality in patients who underwent emergency surgery for acute type A aortic dissection

The study aimed to assess the predictive value of blood urea nitrogen (BUN)-to-albumin ratio (BA-R) for in-hospital mortality in patients undergoing emergency surgery for acute type A aortic dissection (ATAAD). Patients who were diagnosed with ATAAD and underwent emergency surgery within 48 hours of onset at our hospital between January 2015 and December 2021 were included in this study. The primary endpoint of this study was postoperative in-hospital mortality (POIM). The data of the survivors and non-survivors were retrospectively compared analyses. A total of 557 ATAAD patients were included, with 505 survivors and 52 non-survivors. The preoperative BA-R of the non-survivor group was significantly higher than that of the survivor group (P < 0.001). Univariate regression analysis showed that preoperative BA-R, serum creatinine level, SA level, D-dimer level, age, myocardial ischemia, cerebral ischemia, and aortic clamp time were risk factors for POIM. In addition, multivariable regression analysis showed that preoperative BA-R ≥ 0.155 mmol/g was a risk factor for POIM (odds ratio, 6.815 [3.582-12.964]; P < 0.001). Receiver operating characteristic curve indicated that the cut-off point for preoperative BA-R was ≥0.155 mmol/g (area under the curve =0.874). The sensitivity and specificity of preoperative BA-R in predicting the POIM of patients who underwent emergency surgery for ATAAD were 84.6% and 71.3%, respectively (95% confidence interval, 0.829-0.919; P < 0.001). In conclusion, Preoperative BA-R is a simple, rapid, and potentially useful prognostic indicator of POIM in patients with ATAAD. BAR: Blood urea nitrogen-to-albumin ratio, BUN: Blood urea nitrogen, SA: Serum albumin, REF: Reference. The aim of this study was to evaluate the prognostic value of BA-R for the prediction of postoperative in-hospital mortality in patients who underwent emergency surgery for ATAAD. A total of 557 patients with ATAAD were enrolled, and 505 survived while 52 did not. The preoperative BA-R of the non-survivor group was significantly higher than that of the survivor group (0.27 [0.18, 0.46] vs. 0.12 [0.10, 0.16]mmol/g; P < 0.001). The study showed that preoperative BA-R ≥ 0.155 mmol/g was a risk factor for POIM (odds ratio, 6.815 [3.582-12.964]; P < 0.001). ROC curve indicated that the cut-off point for preoperative BA-R was ≥0.155 mmol/g (AUC = 0.874) and the sensitivity and specificity were 84.6% and 71.3%, respectively (95% CI, 0.829-0.919; P < 0.001). We believe that our study makes a significant contribution to the literature because we found preoperative BA-R to be a simple, rapid, and potentially useful prognostic indicator of postoperative in-hospital mortality in patients with ATAAD.

The relationship between lactate dehydrogenase to albumin ratio and all-cause mortality during ICU stays in patients with sepsis: A retrospective cohort study with propensity score matching

Background

Sepsis is a prevalent and severe medical condition which is frequently observed in the intensive care unit (ICU). Although numerous biomarkers have been identified to predict the prognosis of sepsis, the lactate dehydrogenase to albumin ratio (LDH/ALB ratio) has not been extensively investigated. The principal objective of this study is to assess the relationship between LDH/ALB ratio and all-cause mortality in patients with sepsis.

Methods

This study included all adult critically ill patients with sepsis from the Medical Information Mart for Intensive Care IV (MIMIC-IV, version 2.0) database. Propensity score matching (PSM) analysis was conducted to mitigate bias, and Kaplan-Meier curves were performed to evaluate the cumulative survival across different groups. The association between the LDH/ALB ratio and mortality was examined through restricted cubic spline (RCS) analysis and Cox regression analysis. The robustness of the findings was confirmed through subgroup analyses. Additionally, the prognostic capability of the LDH/ALB ratio was further evaluated using receiver operating characteristic (ROC) curve analysis.

Results

There were 6059 adult patients with sepsis enrolled in the final analysis. RCS revealed a non-linear relationship between the LDH/ALB ratio and an increased risk of ICU all-cause mortality (χ2 = 46.900, P < 0.001). Following PSM analysis, 1553 matched pairs were obtained. As comparison to the low LDH/ALB ratio group, the mortality rate in the high LDH/ALB ratio group was significantly higher (P < 0.001). Kaplan-Meier curves, both before and after PSM, revealed that the ICU cumulative survival rate for patients with sepsis was significantly lower in the high LDH/ALB ratio group compared to the low LDH/ALB ratio group (χ2 = 93.360, P < 0.001; χ2 = 14.400, P < 0.001). Even after adjusting for a range of potential confounders, multivariate Cox regression analysis indicated that an elevated LDH/ALB ratio was a significant predictor of all-cause mortality in these patients. ROC curve analysis demonstrated that the LDH/ALB ratio had an area under the ROC curve (AUC) of 0.688 for predicting ICU mortality, with a sensitivity of 69.2% and a specificity of 58.6%.

Conclusions

An elevated LDH/ALB ratio (≥10.57) was associated with all-cause mortality in critically ill patients with sepsis, and it might serve as a prognostic marker. Clinicians should pay closer attention to sepsis patients presenting with an LDH/ALB ratio of 10.57 or higher.

Blood urea nitrogen to serum albumin ratio is associated with all-cause mortality in patients with AKI: a cohort study

Background

This study aims to investigate the relationship between blood urea nitrogen to serum albumin ratio (BAR) and all-cause mortality in patients with acute kidney injury (AKI) and evaluate the effect of BAR on the prognosis of AKI.

Methods

Adult patients with AKI admitted to the ICU in the Medical Information Mart for Intensive Care IV (MIMIC-IV) were selected in a retrospective cohort study. BAR (mg/g) was calculated using initial blood urea nitrogen (mg/dl)/serum albumin (g/dl). According to the BAR, these patients were divided into quartiles (Q1-Q4). Kaplan-Meier analysis was used to compare the mortality of the above four groups. Multivariate Cox regression analysis was used to evaluate the association between BAR and 28-day mortality and 365-day mortality. The receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated, and the subgroup analysis was finally stratified by relevant covariates.

Results

A total of 12,125 patients with AKI were included in this study. The 28-day and 365-day mortality rates were 23.89 and 39.07%, respectively. Kaplan-Meier analysis showed a significant increase in all-cause mortality in patients with high BAR (Log-rank p < 0.001). Multivariate Cox regression analysis showed that BAR was an independent risk factor for 28-day mortality (4.32 < BAR≤7.14: HR 1.12, 95% CI 0.97-1.30, p = 0.114; 7.14 < BAR≤13.03: HR 1.51, 95% CI 1.31-1.75, p < 0.001; BAR>13.03: HR 2.07, 95% CI 1.74-2.47, p < 0.001; Reference BAR≤4.32) and 365-day mortality (4.32 < BAR≤7.14: HR 1.22, 95% CI 1.09-1.36, p < 0.001; 7.14 < BAR≤13.03: HR 1.63, 95% CI 1.46-1.82, p < 0.001; BAR>13.03: HR 2.22, 95% CI 1.93-2.54, p < 0.001; Reference BAR ≤ 4.32) in patients with AKI. The AUC of BAR for predicting 28-day mortality and 365-day mortality was 0.649 and 0.662, respectively, which is better than that of blood urea nitrogen and sequential organ failure assessment. In addition, subgroup analysis showed a stable relationship between BAR and adverse outcomes in patients with AKI.

Conclusion

BAR is significantly associated with increased all-cause mortality in patients with AKI. This finding suggests that BAR may help identify people with AKI at high risk of mortality.

Relationship between blood urea nitrogen to serum albumin ratio and short-term mortality among patients from the surgical intensive care unit: a population-based real-world study

BACKGROUND

Patients admitted to the surgical intensive care unit (SICU) often suffer from multi-organ dysfunction and have a high mortality rate. Therefore, finding a simple but effective clinical indicator to predict the prognosis of patients is essential to improve their survival. The aim of this study was to investigate the relationship between blood urea nitrogen to serum albumin ratio (B/A) and short-term mortality among patients from the SICU.

METHODS

All eligible adult patients admitted to the SICU from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database were recruited for this study. Participants were divided into a death group (n = 638) and a survival group (n = 2,048) based on the 90-day prognosis, and then grouped by B/A quartiles. We used restricted cubic splines (RCS) to visually analyze the correlation of B/A with 30- and 90-day risk of death. Cumulative survival rates were estimated using Kaplan-Meier survival curves according to B/A quartiles and evaluated using the log-rank test. Cox proportional risk models were developed and sensitivity analyses were performed to explore whether B/A was independently associated with short-term outcomes in SICU patients. Receiver operating characteristic (ROC) curves were analyzed to ascertain the value of B/A for prognosticating 90-day outcome.

RESULTS

A total of 2686 participants were included in the final study, and their 30-day and 90-day all-cause mortality rates were 17.61% and 23.75%, respectively. The differences in 30-day and 90-day mortality rates were statistically significant among the four groups of patients (all p < 0.001). RCS curves showed that B/A was linearly associated with the risk of 30-day and 90-day all-cause mortality in SICU patients (χ2 = 0.960, p = 0.811; χ2 = 1.940, p = 0.584). Kaplan-Meier analysis showed that the 90-day cumulative survival rate gradually decreased as B/A increased, with patients in the highest quartile of B/A having the lowest survival rate (p < 0.001). Cox regression indicated that elevated B/A (> 9.69) was an independent risk factor for 30-day and 90-day all-cause mortality in SICU patients. The analysis of ROC curves demonstrated that B/A exhibited a significant predictive ability for 90-day mortality, with an optimal threshold of 6.587, a sensitivity of 56.9%, and a specificity of 64.8%.

CONCLUSIONS

Elevated B/A (> 9.69) on admission was an independent risk factor for short-term mortality in SICU patients, and clinicians should pay more attention to this group of patients and intervene clinically at an early stage to reduce mortality.

A High Preoperative Blood Urea Nitrogen to Serum Albumin Ratio Does Not Predict Worse Outcomes Following the Robotic-Assisted Pulmonary Lobectomy for Lung Cancer

BACKGROUND

 The blood urea nitrogen to serum albumin ratio (BAR) is an emerging prognostic parameter of interest. The utility of BAR as a prognostic factor has not been analyzed in lung cancer patients undergoing pulmonary lobectomy. We evaluated the ability of High BAR to predict worse outcomes after robotic-assisted pulmonary lobectomy (RAPL) for lung cancer.

METHODS

 We retrospectively analyzed 400 patients who underwent RAPL from September 2010 to March 2022 by one surgeon. Patients were stratified by Low BAR (<6.25 mg/g) and High BAR (≥6.25 mg/g). Patients' demographics, tumor characteristics, comorbidities, surgical complications, outcomes, and survival were collected and compared by High and Low BAR groups. The primary outcome of interest was 30-day mortality.

RESULTS

 Receiver operator curves (ROC) confirmed that 6.25 was an optimal threshold for estimating mortality based on Low and High BAR. There were no differences in surgical complications or outcomes between the Low and High BAR groups. The ability of BAR to predict 30-day mortality was evaluated with the area under the curve (AUC) analysis, which showed that higher BAR could not predict mortality (AUC=0.655; 95% CI, 0.435-0.875; p=0.166). Similarly, survival analysis revealed no difference in five-year overall survival between the Low and High BAR groups (p=0.079).

CONCLUSION

 High BAR did not predict worse outcomes after RAPL for lung cancer in our study. Further studies are needed to better determine the prognostic ability of BAR in lower-risk populations.

Role of serum biomarkers in predicting management strategies for acute pulmonary embolism

Background

Acute pulmonary embolism (APE) is a condition that can be fatal. The severity of the disease influences therapeutic decisions, and mortality varies significantly depending on the condition's severity. Identification of patients with a high mortality risk is crucial. Since inflammation, hemostatic, and coagulation abnormalities are linked to APE, serum biomarkers may be helpful for prognostication.

Aim

To evaluate the significance of serum biomarkers in APE risk assessment and the suitability of these biomarkers for management and decision-making.

Methods

This study involved 60 adult patients with APE who were divided according to risk categorization. It was conducted in Chest, Cardiology and Internal Medicine department, Zagazig University Hospitals from December 2022 to May 2023. Several hematological biomarkers and their significance in APE risk assessment were measured with a comparison with the latest risk stratification methods which include haemodynamic measures and right ventricular (RV) dysfunction echocardiographic markers.

Results

Each risk group involved 20 patients (high, intermediate (10 were intermediate-high and 10 were intermediate-low) and low risk group). They were 34 females and 26 males with the mean ± SD of their age was 59.25 ± 13.06 years. Regarding hematological biomarkers, there were statistically significant differences as regards; lymphocytes, platelet to lymphocyte ratio (PLR), albumin, blood urea nitrogen (BUN), C-reactive protein (CRP) and D-dimer with highly statistically significant differences as regards; neutrophil to lymphocyte ratio (NLR), BUN to albumin (B/A) ratio, troponin I (TnI), and brain natriuretic peptide (BNP). TnI had the highest specificity and predictive value positive (PVP) and BNP had the highest sensitivity and predictive value negative (PVN) in predicting high risk groups. The Lymphocyte and NLR showed the lowest sensitivity and the albumin and B/A ratio had the lowest specificity. Regarding transthoracic echocardiography (TEE); there was a statistically significant increase regarding pulmonary artery systolic pressure (PASP) and a highly statistically significant increase regarding the right ventricle/left ventricle (RV/LV) ratio. There were statistically significant decreases regarding tricuspid annular plane systolic excursion (TAPSE) and peak systolic velocity of tricuspid annulus (S') among risk groups.

Conclusion

APE prognosis can be judged accurately by simultaneously measuring a few biomarkers along with haemodynamic variables and echocardiographic parameters of RV dysfunction.

Prognostic value of blood urea nitrogen to serum albumin ratio for acute kidney injury and in-hospital mortality in intensive care unit patients with intracerebral haemorrhage: a retrospective cohort study using the MIMIC-IV database

OBJECTIVE

We sought to evaluate the prognostic ability of blood urea nitrogen to serum albumin ratio (BAR) for acute kidney injury (AKI) and in-hospital mortality in patients with intracerebral haemorrhage (ICH) in intensive care unit (ICU).

DESIGN

A retrospective cohort study using propensity score matching.

SETTING

ICU of Beth Israel Deaconess Medical Center.

PARTICIPANTS

The data of patients with ICH were obtained from the Medical Information Mart for Intensive Care IV (V.1.0) database. A total of 1510 patients with ICH were enrolled in our study.

MAIN OUTCOME AND MEASURE

The optimal threshold value of BAR is determined by the means of X-tile software (V.3.6.1) and the crude cohort was categorised into two groups on the foundation of the optimal cut-off BAR (6.0 mg/g). Propensity score matching and inverse probability of treatment weighting were performed to control for confounders. The predictive performance of BAR for AKI was tested using univariate and multivariate logistic regression analyses. Multivariate Cox regression analysis was used to investigate the association between BAR and in-hospital mortality.

RESULTS

The optimal cut-off value for BAR was 6.0 mg/g. After matching, multivariate logistic analysis showed that the high-BAR group had a significantly higher risk of AKI (OR, 2.60; 95% confidence index, 95% CI, 1.86 to 3.65, p<0.001). What's more, a higher BAR was also an independent risk factor for in-hospital mortality (HR, 2.84; 95% confidence index, 95% CI, 1.96 to 4.14, p<0.001) in terms of multivariate Cox regression analysis. These findings were further demonstrated in the validation cohort.

CONCLUSIONS

BAR is a promising and easily available biomarker that could serve as a prognostic predictor of AKI and in-hospital mortality in patients with ICH in the ICU.

BUN/albumin ratio predicts short-term mortality better than SYNTAX score in ST-elevation myocardial infarction patients

OBJECTIVE

The aim of the study is to compare the prognostic power of the BUN/albumin ratio (BAR) calculated on admission to the emergency department and the SYNergy between Percutaneous Coronary Intervention with TAXus (SYNTAX) score calculated after coronary angiography (CAG) in predicting 30-day mortality in patients with ST-segment elevation myocardial infarction (STEMI).

METHOD AND MATERIAL

The study was conducted prospectively between March 2021 and March 2022 in the emergency department of a tertiary hospital. Patients over the age of 18 who underwent CAG with a diagnosis of STEMI were included in the study. Demographic charecteristics, comorbidities, laboratory parameters of the patients at the time of admission and SYNTAX (SX) score were recorded in the data form.

RESULTS

A total of 1147 patients (77% male) diagnosed with STEMI were included in the study. When the receiver-operating characteristic analysis for SX score and laboratory parameters' power to predict mortality was examined, it was found that the AUC value of the BAR level (AUC: 0.736; 95% confidence interval: 0.670-0.802, P  < 0.001) was the highest. If the threshold value of the serum BAR level, which was determined to predict mortality, was taken as 4, the sensitivity was found to be 76.7% and the specificity was 56.9%. With multivariate logistic analysis, it was determined that the risk of mortality increased by 1.25 for each unit increase in the BAR value in STEMI patients ( P  < 0.001).

CONCLUSION

According to the study data, the BAR may guide the clinician in the early period as a practical and valuable predictor of 30-day mortality in patients diagnosed with STEMI.

Efficacy of blood urea nitrogen-to-albumin ratio for predicting prognostic outcomes of inpatients with COVID-19: A meta-analysis

BACKGROUND

The associations between blood urea nitrogen (BUN)/albumin ratio and poor prognosis in patients with diagnosis of coronavirus disease 2019 (COVID-19) remain to be clarified.

METHODS

A search based on 4 electronic databases (i.e., EMBASE, Google scholar, MEDLINE, and Cochrane Library) was performed on June 23, 2022. The association of BUN/Albumin ratio with poor prognostic outcomes, defined as patients with mortality/severe illnesses, were analyzed.

RESULTS

Results from analysis of 7 cohort studies (3600 individuals with COVID-19) published between 2020 and 2022 showed a higher BUN/Albumin ratio in the poor-prognosis group (Mean difference:  = 2.838, 95% confidence interval: 2.015-3.66, P < .001, I2 = 92.5%) than the good-prognosis group. Additional investigation into the connection between BUN/Albumin ratio as a binary variable (i.e., high or low) and the risk of poor outcome also supported an association between a higher BUN/Albumin ratio and a poor prognostic risk (odd ratio = 3.009, 95% confidence interval: 1.565-5.783, P = .001, I2 = 93.7%, 5 studies). Merged analysis of poor prognosis produced a sensitivity of 0.76, specificity of 0.72, and area under curve of 0.81.

CONCLUSION

This meta-analysis demonstrated a positive correlation between BUN/albumin ratio and poor outcome in patients with COVID-19. Additional large-scale prospective studies are needed to verify our findings.

Establishment and validation of a predictive nomogram for gestational diabetes mellitus during early pregnancy term: A retrospective study

OBJECTIVE

This study aims to develop and evaluate a predictive nomogram for early assessment risk factors of gestational diabetes mellitus (GDM) during early pregnancy term, so as to help early clinical management and intervention.

METHODS

A total of 824 pregnant women at Zhongnan Hospital of Wuhan University and Maternal and Child Health Hospital of Hubei Province from 1 February 2020 to 30 April 2020 were enrolled in a retrospective observational study and comprised the training dataset. Routine clinical and laboratory information was collected; we applied least absolute shrinkage and selection operator (LASSO) logistic regression and multivariate ROC risk analysis to determine significant predictors and establish the nomogram, and the early pregnancy files (gestational weeks 12-16, n = 392) at the same hospital were collected as a validation dataset. We evaluated the nomogram via the receiver operating characteristic (ROC) curve, C-index, calibration curve, and decision curve analysis (DCA).

RESULTS

We conducted LASSO analysis and multivariate regression to establish a GDM nomogram during the early pregnancy term; the five selected risk predictors are as follows: age, blood urea nitrogen (BUN), fibrinogen-to-albumin ratio (FAR), blood urea nitrogen-to-creatinine ratio (BUN/Cr), and blood urea nitrogen-to-albumin ratio (BUN/ALB). The calibration curve and DCA present optimal predictive power. DCA demonstrates that the nomogram could be applied clinically.

CONCLUSION

An effective nomogram that predicts GDM should be established in order to help clinical management and intervention at the early gestational stage.

The correlation study between blood urea nitrogen to serum albumin ratio and prognosis of patients with sepsis during hospitalization

BACKGROUND

Sepsis is a common critical illness in intensive care unit (ICU) and seriously threatens the life of patients. Therefore, to identify a simple and effective clinical indicator to determine prognosis is essential for the management of sepsis patients. This study was mainly based on blood urea nitrogen to albumin ratio (B/A), a comprehensive index, to explore its correlation with the prognosis of sepsis patients during hospitalization.

METHODS

Totally, adult patients in ICU who were diagnosed with sepsis in Medical Information Mart for Intensive Care IV(MIMIC-IV) database from 2008 to 2019 were involved in this study. The study population were divided into survivors group and non-survivors group based on the prognosis during hospitalization. Restricted cubic spline (RCS) was utilized to analyze the association between B/A level and the risk of ICU all-cause mortality in patients with sepsis and determine the optimal cut-off value of B/A. The study population was divided into low B/A group and high B/A group based on the optimal cut-off value. The survival curve of ICU cumulative survival rate was draw through Kaplan-Meier method. The correlation between B/A and the prognosis of patients was conducted by multivariate Cox regression analysis. Furthermore, we performed sensitivity analyses to assess the robustness of the results.

RESULTS

A total of 10,578 patients with sepsis were enrolled, and the ICU all-cause mortality was 15.89%. The patients in the non-survivors group had higher B/A values and more comorbidities than those in the survivors group. RCS showed that the risk of ICU all-cause mortality increased with the B/A level, showing a non-linear trend (χ2 = 66.82, p < 0.001). The mortality rate in the high B/A group was significantly higher than that in the low B/A group (p < 0.001). Kaplan-Meier curves revealed that compared with the low B/A group, the ICU cumulative survival rate of patients with sepsis was significantly lower in the high B/A group (log-rank test, χ2 = 148.620, p < 0.001). Further analysis of multivariate Cox proportional hazards regression showed that an elevated B/A (≥ 7.93) was an independent factor associated with ICU mortality among patients with sepsis.

CONCLUSIONS

An elevated B/A might be a useful prognostic indicator in patients with sepsis. This study could offer a deeper insight into treating sepsis.

Blood urea nitrogen to serum albumin ratio: a good predictor of in-hospital and 90-day all-cause mortality in patients with acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Previous studies on acute exacerbation of chronic obstructive pulmonary disease (AECOPD) have found that those who died in hospital had higher blood urea nitrogen levels and a worse nutritional status compared to survivors. However, the association between the blood urea nitrogen to serum albumin ratio (BUN/ALB ratio) and in-hospital and short-term prognosis in patients with AECOPD remains unclear. The aim of this study was to explore the usefulness of BUN/ALB ratio in AECOPD as an objective predictor for in-hospital and 90-day all-cause mortality.

METHODS

We recorded the laboratory and clinical data in patients with AECOPD on admission. By drawing the ROC curve for the patients, we obtained the cut-off point for the BUN/ALB ratio for in-hospital death. Multivariate logistic regression was used for analyses of the factors of in-hospital mortality and multivariate Cox regression was used to analyze the factors of 90-day all-cause mortality.

RESULTS

A total of 362 patients were recruited and 319 patients were finally analyzed. Twenty-three patients died during hospitalization and the fatality rate was 7.2%. Furthermore, 14 patients died by the 90-day follow-up. Compared with in-hospital survivors, patients who died in hospital were older (80.78 ± 6.58 vs. 75.09 ± 9.73 years old, P = 0.001), had a higher prevalence of congestive heart failure(69.6% vs. 27.4%, P < 0.001), had a higher BUN/ALB ratio [0.329 (0.250-0.399) vs. 0.145 (0.111-0.210), P < 0.001], had higher neutrophil counts [10.27 (7.21-14.04) vs. 6.58 (4.58-9.04), P < 0.001], higher blood urea nitrogen levels [10.86 (7.10-12.25) vs. 5.35 (4.14-7.40), P < 0.001], a lower albumin level (32.58 ± 3.72 vs. 36.26 ± 4.53, P < 0.001) and a lower lymphocyte count [0.85 (0.58-1.21) vs. 1.22 (0.86-1.72), P = 0.001]. The ROC curve showed that the area under the curve (AUC) of BUN/ALB ratio for in-hospital death was 0.87, (95%CI 0.81-0.93, P < 0.001), the best cut-off point value to discriminate survivors from non-survivors in hospital was 0.249, the sensitivity was 78.3%, the specificity was 86.5%, and Youden's index was 0.648. Having a BUN/ALB ratio ≥ 0.249 was an independent risk factor for both in-hospital and 90-day all-cause mortality after adjustment for relative risk (RR; RR = 15.08, 95% CI 3.80-59.78, P < 0.001 for a multivariate logistic regression analysis) and hazard ratio (HR; HR = 5.34, 95% CI 1.62-17.57, P = 0.006 for a multivariate Cox regression analysis).

CONCLUSION

An elevated BUN/ALB ratio was a strong and independent predictor of in-hospital and 90-day all-cause mortality in patients with AECOPD.

Association between blood urea nitrogen to serum albumin ratio and in-hospital mortality of patients with sepsis in intensive care: A retrospective analysis of the fourth-generation Medical Information Mart for Intensive Care database

BACKGROUND

This study aimed to investigate the relationship between the blood urea nitrogen to serum albumin ratio (BAR) and in-hospital mortality in patients with sepsis.

MATERIALS AND METHODS

This is a retrospective cohort study. All septic patient data for the study were obtained from the intensive care unit of Beth Israel Deaconess Medical Center. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using multivariable Cox regression analyses. Survival curves were plotted and subgroup analyses were stratified by relevant covariates.

RESULTS

Among 23,901 patients, 13,464 with sepsis were included. The overall in-hospital mortality rate was 18.9% (2550/13464). After adjustment for confounding factors, patients in the highest BAR quartile had an increased risk of sepsis death than those in the lowest BAR quartile (HR: 1.42, 95% CI: 1.3-1.55), using BAR as a categorical variable. When BAR was presented as a continuous variable, the prevalence of in-hospital sepsis-related death increased by 8% (adjusted HR: 1.08, 95% CI: 1.07-1.1, P < 0.001) for each 5-unit increase in BAR, irrespective of confounders. Stratified analyses indicated age interactions (P < 0.001), and the correlation between BAR and the probability of dying due to sepsis was stable.

CONCLUSION

BAR was significantly associated with in-hospital mortality in intensive care patients with sepsis. A higher BAR in patients with sepsis is associated with a worse prognosis in the ICU in the USA. However, further research is required to confirm this finding.

Association Between Blood Urea Nitrogen Levels and Length of Stay in Patients with Pneumonic Chronic Obstructive Pulmonary Disease Exacerbation: A Secondary Analysis Based on a Multicentre, Retrospective Cohort Study

Purpose

High blood urea nitrogen (BUN) is associated with an elevated risk of mortality in various diseases, such as heart failure and pneumonia. Heart failure and pneumonia are common comorbidities of chronic obstructive pulmonary disease (COPD) exacerbation. However, data on the relationship of BUN levels with length of stay (LOS) in patients with pneumonic COPD exacerbation are sparse. The purpose of this study was to evaluate the correlation between BUN levels and LOS in a cohort of patients with pneumonic COPD exacerbation.

Patients and Methods

The present study was a multicentre, retrospective cohort study. A total of 1226 patients with pneumonic COPD exacerbation were included through a validated algorithm derived from the 10th revision of the International Classification of Diseases and Related Health Problems (ICD-10). It should be noted that the entire study was completed by Shiroshita et al, who uploaded the data to the DATADRYAD website. The author only used these data for secondary analysis.

Results

After adjusting for potential confounders (age, gender), a nonlinear relationship was detected between BUN levels less than 40 mg/dl and LOS. The effect sizes and the confidence intervals on the left and right sides of the inflection point were 0.27 (0.16, 0.39) and −0.17 (−0.34, 0.01), respectively.

Conclusion

High levels of BUN in the hospital may be associated with increased LOS. BUN was positively related to LOS when BUN was less than 40 mg/dl.

Lactate dehydrogenase/albumin ratio as a prognostic factor in severe acute respiratory distress syndrome cases associated with COVID-19

BACKGROUND

Patients with severe acute respiratory distress syndrome (ARDS) have high mortality rates; therefore, new biomarkers are necessary to predict the prognosis in the early stages. Serum lactate dehydrogenase (LDH) level is a specific marker of lung damage, but it is not sensitive because it is affected by several factors. This study aimed to determine whether the LDH/albumin ratio could be used as a prognostic biomarker in patients with severe ARDS due to COVID 19.

METHODS

Tertiary intensive care unit (ICU) patients with severe ARDS and confirmed COVID-19 diagnosis between August 1, 2020, and October 31, 2021, were included. The demographic and clinical characteristics of the patients were recorded from the hospital databases, together with laboratory results on the day of admission to the ICU and the length of stay in the ICU and hospital. LDH/albumin, lactate/albumin, C-reactive protein (CRP)/albumin, and BUN/albumin ratios were calculated. Logistic regression analysis was performed to determine independent risk factors affecting mortality.

RESULTS

Nine hundred and five patients hospitalized in a tertiary ICU were evaluated. Three hundred fifty-one patients with severe ARDS were included in this study. The mortality rate of the included patients was 61.8% (of 217/351). LDH/albumin, lactate/albumin, and BUN/albumin ratios were higher in the nonsurvivor group (P < .001). The area under the curve (AUC) from the receiver operating characteristic analysis that predicted in-hospital mortality was 0.627 (95% confidence intervals (CI): 0.574-0.678, P < .001) for the LDH/albumin ratio, 0.605 (95% CI: 0.551-0.656, P < .001) for lactate/albumin, and 0.638 (95% CI: 0.585-0.688, P < .001) for BUN/albumin. However, LDH/albumin ratio was independently associated with mortality in multivariate logistic regression analysis.

CONCLUSION

LDH/albumin ratio can be used as an independent prognostic factor for mortality in patients with severe ARDS caused by COVID-19.

Blood urea nitrogen/albumin ratio on admission predicts mortality in patients with non ST segment elevation myocardial infarction

The aim of this study is to reveal the predictive power of biomarkers and SYNTAX (SX) score for short-term mortality in patients diagnosed with non-ST-segment elevation myocardial infarction (NSTEMI) in the emergency department. This is prospective observational cohort study. Demographic characteristics of the patients, laboratory parameters on admission, left ventricular ejection fraction (LVEF) percentages, affected vessels in angiography (CAG) and the treatment strategy [medical therapy, percutaneous transluminal coronary angioplasty (PTCA), coronary angio by-pass graft] and SX scores were recorded on the data collection form. ROC curve was used to investigate the predictivity of blood urea nitrogen/albumin ratio (BAR), procalcitonin, C-reactive protein (CRP), high sensitivity cardiac troponin I (Hs-cTnI), CRP to serum albumin ratio (CAR), neutrophil to lymphocyte ratio (NLR) and SX scores in mortality. Multivariate analysis of biomarkers and SX score was performed to estimate the patients' 30-day mortality. Of the 415 patients were included in the study. ROC analysis of BAR, CAR, CRP, Procalcitonin, Hs-cTnI, NLR and SX score to predict mortality was statistically significant. BAR (OR: 1.280, 95% CI: 1.113-1.472, p = .001) and SX score (OR: 1.071, 95% CI: 1.018-1.126, p = .007) were found to be independent predictors of 30 days mortality. LVEF reduction, SX score, the number of affected vessels and the frequency of LMCA lesions increase were found to be statistically significant in patients with BAR ≥4.8. BAR, which can be calculated easily and quickly on admission to the emergency department and in clinical practice, may be used to predict mortality in patients with NSTEMI.

Association Between Pre-operative BUN and Post-operative 30-Day Mortality in Patients Undergoing Craniotomy for Tumors: Data From the ACS NSQIP Database

Objective

There is limited evidence to clarify the specific relationship between pre-operative blood urea nitrogen (BUN) and post-operative 30-day mortality in patients undergoing craniotomy for tumors. Therefore, we aimed to investigate this relationship in detail.

Methods

Electronic medical records of 18,642 patients undergoing craniotomy for tumors in the ACS NSQIP from 2012 to 2015 were subjected to secondary retrospective analysis. The principal exposure was pre-operative BUN. Outcome measures were post-operative 30-day mortality. We used binary logistic regression modeling to evaluate the association between them and conducted a generalized additive model and smooth curve fitting (penalized spline method) to explore the potential relationship and its explicit curve shape. We also conducted sensitivity analyses to ensure the robustness of the results and performed subgroup analyses.

Results

A total of 16,876 patients were included in this analysis. Of these, 47.48% of patients were men. The post-operative 30-day mortality of the included cases was 2.49% (420/16,876), and the mean BUN was 16.874 ± 6.648 mg/dl. After adjusting covariates, the results showed that pre-operative BUN was positively associated with post-operative 30-day mortality (OR = 1.020, 95% CI: 1.004, 1.036). There was also a non-linear relationship between BUN and post-operative 30-day mortality, and the inflection point of the BUN was 9.804. For patients with BUN < 9.804 mg/dl, a 1 unit decrease in BUN was related to a 16.8% increase in the risk of post-operative 30-day mortality (OR = 0.832, 95% CI: 0.737, 0.941); for patients with BUN > 9.804 mg/dl, a 1 unit increase in BUN was related to a 2.8% increase in the risk of post-operative 30-day mortality (OR = 1.028, 95% CI: 1.011, 1.045). The sensitivity analysis proved that the results were robust. The subgroup analysis revealed that all listed subgroups did not affect the relationship between pre-operative BUN and post-operative 30-day mortality (P > 0.05).

Conclusion

Our study demonstrated that pre-operative BUN (mg/dl) has specific linear and non-linear relationships with post-operative 30-day mortality in patients over 18 years of age who underwent craniotomy for tumors. Proper pre-operative management of BUN and maintenance of BUN near the inflection point (9.804 mg/dl) could reduce the risk of post-operative 30-day mortality in these cases.

Prognostic value of blood urea nitrogen-to-serum albumin ratio for mortality of pneumonia in patients receiving glucocorticoids: Secondary analysis based on a retrospective cohort study

INTRODUCTION

Previous studies have revealed that blood urea nitrogen-to-serum albumin ratio (BUN/ALB) is one of major risk factors of mortality in pneumonia. However, there are fewer scientific research about the correlation between BUN/ALB ratio and outcome of pneumonia in patients receiving glucocorticoids. This study was undertaken to explore the prognostic value of BUN/ALB ratio for mortality of pneumonia in patients receiving glucocorticoids.

METHODS

The present study was a retrospective cohort study. 1397 subjects receiving glucocorticoids alone or glucocorticoids and other immunosuppressants from six secondary and tertiary academic hospitals in China were analyzed. The endpoint of the study was 30-day mortality. It was noted that the entire study was completed by Li et al. and uploaded the data to the DATADRYAD website. The author only used this data for secondary analysis.

RESULTS

After adjusting potential confounders (age, sex, WBC, persistent lymphocytopenia, PLT, ALT, AST, Cr, high-dose steroid use, and COPD), non-linear relationship was detected between BUN/ALB ratio and 30-day mortality, whose point was 0.753. The effect sizes and the confidence intervals on the left and right sides of inflection point were 23.110 (7.157, 74.623) and 0.410 (0.074, 2.283), respectively. Subgroup analysis revealed the positive association was stronger among subjects with connective tissue disease.

CONCLUSIONS

The relationship between BUN/ALB ratio and 30-day mortality of pneumonia in patients receiving glucocorticoids is non-linear. BUN/ALB ratio is positively related with 30-day mortality when BUN/ALB ratio is less than 0.753.

The role of blood urea nitrogen to serum albumin ratio in the prediction of severity and 30‐day mortality in patients with COVID‐19

Background

Considering the role of higher blood urea nitrogen and lower serum albumin (SA) levels in deceased coronavirus disease 2019 (COVID‐19) patients, an increased blood urea nitrogen to SA (B/A) ratio may help to determine those at higher risk of critical illness. This study aimed to evaluate the correlation of the B/A ratio with severity and 30‐day mortality in COVID‐19 patients.

Methods

A total of 433 adult patients with COVID‐19 were enrolled. The laboratory markers were measured on admission. Disease severity was categorized into mild disease, severe pneumonia, acute respiratory distress syndrome (ARDS), sepsis, and septic shock. The mortality was followed for 30 days after admission. χ² test, Fisher's exact test, and Mann–Whitney U test were performed, as appropriate. Also, logistic regression and the receiver operating characteristic (ROC) curve for the B/A ratio are included.

Results

Thirty‐day mortality rate was 27.25%. The frequency of mild, severe pneumonia, ARDS, sepsis, and septic shock was 30.72%, 36.95%, 24.02%, 6.00%, and 2.31%, respectively. B/A ratio and SA levels were statistically different between alive and deceased patients. The mean B/A ratio was different among classified disease severities, except for mild disease. Logistic regression revealed the B/A ratio as an independent risk factor for sepsis after adjusting for age and sex. ROC analysis showed B/A ratio had an area under the curve (AUC) of 0.733 for mortality at the cutpoint of 4.944. AUC for sepsis was 0.617 which was greater than other disease severities.

Conclusion

The results showed that B/A ratio and SA levels are associated with mortality of COVID‐19 patients. A higher B/A ratio is, additionally, associated with COVID‐19 severity, except in mild cases and it can act as an independent risk factor in sepsis. However, a greater B/A ratio is not a significant predictor of COVID‐19 severity, but it can predict mortality. Therefore, we suggest this marker for clinical assessment of patients with severe COVID‐19.

Blood Urea Nitrogen/Albumin Ratio and Mortality Risk in Patients with COVID-19

Introduction

We researched blood urea nitrogen (BUN), albumin and their ratio (BAR), and compared them with C-reactive protein (CRP), D-dimer, and computed tomography severity scores (CT-SS), to predict in-hospital mortality.

Methods

One-hundred and thirty-one coronavirus disease-2019 (COVID-19) confirmed patients brought to the emergency department (ED) were dispensed to the survivor or non-survivor group, in light of in-hospital mortality. Information on age, gender, complaints, comorbidities, laboratory parameters, and outcome were gathered from the patient's record files.

Results

The median BUN, mean total protein, mean albumin, median BAR, median creatinine, median CRP, and median D-dimer were recorded. CT-SS were utilized in categorizing the patient as mild, moderate, and severe. In-hospital mortality occurred in 42 (32.06%) patients (non-survivor group) and did not occur in 89 (67.94%) patients (survivor group). The median BUN (mg/dL) and BAR (mg/gm) values were significantly raised in the non-survivor group than in the survivor group [BUN: 23.48 (7.51–62.75) and 20.66 (4.07–74.67), respectively (p = 0.009); BAR: 8.33 mg/g (2.07–21.86) and 6.11 mg/g (1.26–23.33); (p = 0.0003)]. The mean albumin levels (gm/dL) in the non-survivor group were significantly lower than in the survivor group [2.96 ± 0.35 and 3.27 ± 0.35, respectively (p <0.0001)]. Albumin with an odd's ratio of 6.14 performed the best in predicting in-hospital mortality, followed by D-dimer (4.98). BAR and CRP had similar outcome of 3.75; BUN showed an OR of 3.13 at the selected cutoff value.

Conclusion

The BUN, albumin, and BAR were found to be dependable predictors of in-hospital mortality in COVID-19 patients, with albumin (hypoalbuminemia) performing even better.

How to cite this article

Singh S, Singh K. Blood Urea Nitrogen/Albumin Ratio and Mortality Risk in Patients with COVID-19. Indian J Crit Care Med 2022;26(5):626–631.

Risk Factors Associated with In-Hospital Mortality in Iranian Patients with COVID-19: Application of Machine Learning

Introduction: Predicting the mortality risk of COVID-19 patients based on patient’s physiological conditions and demographic characteristics can help optimize resource consumption along with the provision of effective medical services for patients. In the current study, we aimed to develop several machine learning models to forecast the mortality risk in COVID-19 patients, evaluate their performance, and select the model with the highest predictive power.

Material and methods: We conducted a retrospective analysis of the records belonging to COVID-19 patients admitted to one of the main hospitals of Qazvin located in the northwest of Iran over 12 months period. We selected 29 variables for developing machine learning models incorporating demographic factors, physical symptoms, comorbidities, and laboratory test results. The outcome variable was mortality as a binary variable. Logistic regression analysis was conducted to identify risk factors of in-hospital death.

Results: In prediction of mortality, Ensemble demonstrated the maximum values of accuracy (0.8071, 95%CI: 0.7787, 0.8356), F1-score (0.8121 95%CI: 0.7900, 0.8341), and AUROC (0.8079, 95%CI: 0.7800, 0.8358). Including fourteen top-scored features identified by maximum relevance minimum redundancy algorithm into the subset of predictors of ensemble classifier such as BUN level, shortness of breath, seizure, disease history, fever, gender, body pain, WBC, diarrhea, sore throat, blood oxygen level, muscular pain, lack of taste and history of drug (medication) use are sufficient for this classifier to reach to its best predictive power for prediction of mortality risk of COVID-19 patients.

Conclusions: Study findings revealed that old age, lower oxygen saturation level, underlying medical conditions, shortness of breath, seizure, fever, sore throat, and body pain, besides serum BUN, WBC, and CRP levels, were significantly associated with increased mortality risk of COVID-19 patients. Machine learning algorithms can help healthcare systems by predicting and reduction of the mortality risk of COVID-19 patients.

Blood urea nitrogen to serum albumin ratio as a new prognostic indicator in critical patients with chronic heart failure

Aims

Chronic heart failure (CHF) is often a common comorbidity in critically ill patients admitted to the intensive care unit (ICU) and carries an extremely poor prognosis. The study aimed to investigate the relationship between the blood urea nitrogen to serum albumin ratio (BAR) and the prognosis of patients with CHF admitted to the ICU.

Methods and results

This retrospective cohort study included 1545 critically ill patients with CHF as a diagnosed comorbidity admitted to the ICU deposited in the MIMIC‐III database, of whom 90 day all‐cause mortality was 27.6% (n = 427) and in‐hospital mortality was 17.3% (n = 267). The results of multiple logistic regression analysis indicated that BAR is an independent risk factor for in‐hospital mortality in critically ill patients with CHF [compared with BAR ≤ 0.83; 0.83 < BAR ≤ 1.24: odds ratio (OR) 2.647, 95% confidence interval (CI) 1.797–3.900, P < 0.001; BAR ≥ 1.24: OR 3.628, 95% CI 2.604–5.057, P < 0.001]. Multiple COX regression analysis found a relationship between BAR and all‐cause mortality at 90 day follow‐up (0.83 < BAR ≤ 1.24: OR 1.948, 95% CI 1.259–3.014, P < 0.003; BAR ≥ 1.24: OR 1.807, 95% CI 1.154–2.830, P < 0.01; BAR ≤ 0.83 as a reference). Kaplan–Meier curves also showed similar results as well (P < 0.001). The areas under the receiver operating characteristic curves for predicting in‐hospital mortality and 90 day all‐cause mortality were 0.622 and 0.647, respectively.

Conclusions

BAR is an independent risk factor for in‐hospital mortality and 90 day mortality in critically ill patients with CHF admitted to the ICU.

Can blood urea Nitrogen-to-Albumin ratio predict mortality in patients with moderate-to-severe COVID-19 pneumonia hospitalized in the intensive care unit?

OBJECTIVE

Many laboratory parameters allow to follow up the course of the disease and reveal its clinical severity, particularly in patients with coronavirus disease 2019 (COVID-19) pneumonia. In this study, we aimed to investigate the role of the blood urea nitrogen-to-albumin ratio in predicting the mortality in COVID-19 patients with moderate-to-severe disease who are hospitalized in the intensive care unit.

METHODS

A total of 358 patients who were hospitalized in intensive care unit at our hospital between November 1, 2020 and May 15, 2021 were included in this study. During their course of intensive care, surviving patients were included in Group 1 and nonsurviving patients in Group 2.

RESULTS

There were no statistically significant differences between the two groups in terms of gender, smoking, and chronic obstructive pulmonary disease rates. In multivariate logistic regression analysis, advanced age (OR 1.038, 95%CI 1.014-1.064, p=0.002), neutrophil-to-lymphocyte ratio (OR 1.226, 95%CI 1.020-1.475, p=0.030), blood urea nitrogen-to-albumin ratio (OR 2.693, 95%CI 2.019-3.593, p<0.001), and chest computed tomography severity score (OR 1.163, 95%CI 1.105-1.225, p<0.001) values were determined as independent predictors for in-hospital mortality.

CONCLUSION

In this study, we showed that the blood urea nitrogen-to-albumin ratio, which was previously shown as a predictor of mortality in patients with various pneumonia, was an independent predictor of mortality in patients with COVID-19 pneumonia.

Do biomarkers have predictive value in the treatment modality of the patients diagnosed with bowel obstruction?

OBJECTIVES

This study aimed to investigate the ability of the biomarkers to predict the surgery treatment and mortality in patients above 18 years of age who were hospitalized with the diagnosis of bowel obstruction from the emergency department.

METHODS

This is a 2-year retrospective study. The patients' demographic data, laboratory parameters on admission to emergency department, treatment modalities, and the length of hospital stay were recorded. Patients were divided into two groups: conservative and surgical treatment. Statistical analysis was performed to investigate the value of biomarkers in predicting mortality and the need for surgery. Data were analyzed using IBM SPSS version 22.

RESULTS

A total of 179 patients were included in this study. Of these, 105 (58.7%) patients were treated conservative and 74 (41.3%) were treated operatively. The elevated procalcitonin (PCT) level, C-reactive protein, blood urea nitrogen-to-albumin ratio, and lactate-to-albumin ratio were significantly correlated with surgical treatment, length of hospital stay, and mortality. procalcitonin threshold value of 0.13 ng/mL was able to predict the need for surgical treatment, with a sensitivity of 79% and a specificity of 70.3%. Procalcitonin threshold value of 0.65 ng/mL was able to predict the mortality rate of the patients, with a sensitivity of 92.9% and a specificity of 78.1%.

CONCLUSIONS

Biomarkers, especially procalcitonin, may be useful in bowel obstruction treatment management and may predict mortality.

The association of blood urea nitrogen levels upon emergency admission with mortality in acute exacerbation of chronic obstructive pulmonary disease

Background and purpose

High blood urea nitrogen (BUN) is associated with an elevated risk of mortality in various diseases, such as heart failure and pneumonia. Heart failure and pneumonia are common comorbidities of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). However, data on the relationship of BUN levels with mortality in patients with AECOPD are sparse. The purpose of this study was to evaluate the correlation between BUN level and in-hospital mortality in a cohort of patients with AECOPD who presented at the emergency department (ED).

Methods

A total of 842 patients with AECOPD were enrolled in the retrospective observational study from January 2018 to September 2020. The outcome was all-cause in-hospital mortality. Receiver operating characteristic (ROC) curve analysis and logistic regression models were performed to evaluate the association of BUN levels with in-hospital mortality in patients with AECOPD. Propensity score matching was used to assemble a cohort of patients with similar baseline characteristics, and logistic regression models were also performed in the propensity score matching cohort.

Results

During hospitalization, 26 patients (3.09%) died from all causes, 142 patients (16.86%) needed invasive ventilation, and 190 patients (22.57%) were admitted to the ICU. The mean level of blood urea nitrogen was 7.5 ± 4.5 mmol/L. Patients in the hospital non-survivor group had higher BUN levels (13.48 ± 9.62 mmol/L vs. 7.35 ± 4.14 mmol/L, p < 0.001) than those in the survivor group. The area under the curve (AUC) was 0.76 (95% CI 0.73–0.79, p < 0.001), and the optimal BUN level cutoff was 7.63 mmol/L for hospital mortality. As a continuous variable, BUN level was associated with hospital mortality after adjusting respiratory rate, level of consciousness, pH, PCO_2, lactic acid, albumin, glucose, CRP, hemoglobin, platelet distribution width, D-dimer, and pro-B-type natriuretic peptide (OR 1.10, 95% CI 1.03–1.17, p=0.005). The OR of hospital mortality was significantly higher in the BUN level ≥7.63 mmol/L group than in the BUN level <7.63 mmol/L group in adjusted model (OR 3.29, 95% CI 1.05–10.29, p=0.041). Similar results were found after multiple imputation and in the propensity score matching cohort.

Conclusions

Increased BUN level at ED admission is associated with hospital mortality in patients with AECOPD who present at the ED. The level of 7.63 mmol/L can be used as a cutoff value for critical stratification.

Prognostic Value of Blood Urea Nitrogen to Serum Albumin Ratio in Intensive Care Unit Patients with Lung Cancer

Background

We aimed to evaluate the prognostic ability of blood urea nitrogen (BUN) to serum albumin ratio (BAR) to predict in-hospital mortality in patients with lung cancer in the intensive care unit (ICU).

Methods

Medical Information Mart for Intensive Care IV (MIMIC-IV v1.0) database was used to identify patients who were diagnosed with lung cancer. The primary outcome was in-hospital mortality. Multivariate COX regression was used to investigate the association between BAR and in-hospital mortality and propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were also used to ensure the robustness of our findings. eICU-CRD database (validation cohort) was also applied to validate our findings.

Results

The optimal cut-off value for BAR was 6.8mg/g. Among 1202 patients who were diagnosed with lung cancer, 287 high-BAR group (≥6.8mg/g) patients and 287 low-BAR group (<6.8mg/g) patients, who had similar propensity scores were included in this study. After matching, the high-BAR group had significantly higher in-hospital mortality (hazard ratio, HR, 2.24, 95% confidence index, 95% CI, 1.57–3.19, P<0.001) even after adjustment for confounding factors. Moreover, the performance of BAR was superior to that of BUN and serum albumin alone and could add net benefit in predicting in-hospital mortality. Those results were further confirmed in the validation cohort.

Conclusion

As an easily accessible and cost-effective parameter, BAR could serve as a good prognostic predictor for lung cancer patients in ICU.

Urea-to-Albumin Ratio and In-Hospital Mortality in Severe Pneumonia Patients

Objective

The urea-to-albumin ratio (UAR), as a new marker of the systemic inflammatory response, is associated with the mortality in pneumonia patients. However, the association between the UAR and in-hospital mortality in severe pneumonia (SP) has received little attention.

Methods

In this single-center retrospective cohort study, 212 SP patients in intensive care unit (ICU) from June 1, 2016, to June 1st, 2020, with baseline UAR were enrolled. The primary outcome was in-hospital mortality. The association of UAR with in-hospital mortality was assessed using a multivariable-adjusted Cox model.

Results

Of 212 patients, the median age was 73.0 (61.0, 82.8) years, 70.8% of patients were male, and the APACHE II score was 20.0 (16.0, 26.0). During the hospital period, 101 (47.6%) patients died. In-hospital mortality rates for the lower and higher UAR were 16 (27.6%) and 85 (55.2%), respectively (P < 0.001). Kaplan–Meier analysis revealed that survival rates were significantly different between the two groups (log rank = 13.71, P < 0.001). After adjusted for confounding factors, the higher UAR group was significantly associated with a hazard ratio (HR) for in-hospital mortality of 2.234 (95% confidence interval: 1.146–4.356, P=0.018). Besides, this pattern persisted in subgroup analyses considering sex (HR = 9.380; 95% CI: 2.248–39.138; P=0.002).

Conclusions

Higher UAR levels at the commencement of admission to ICU may be independently associated with increased in-hospital mortality in SP patients.

Lactate dehydrogenase to albumin ratio as a prognostic factor for patients with severe infection requiring intensive care

This study was performed to verify whether lactate dehydrogenase to albumin (LDH/ALB) ratio could be used as an independent prognostic factor in patients with severe infection requiring intensive care.We reviewed electronic medical records of patients hospitalized to the intensive care unit via the emergency department with a diagnosis of infection between January 2014 and December 2019. From the collected data, ALB-based ratios (LDH/ALB, blood urea nitrogen to albumin, C-reactive protein to albumin, and lactate to albumin ratios) and some severity scores (modified early warning score, mortality in emergency department sepsis score [MEDS], and Acute Physiology And Chronic Health Evaluation II [APACHE II] score) were calculated. LDH/ALB ratio for predicting the in-hospital mortality was compared with other ALB-based ratios and severity scales by univariable and receiver-operating characteristics curve analysis. Modified severity scores by LDH/ALB ratio and multivariable logistic regression were used to verify the independence and usefulness of the LDH/ALB ratio.The median LDH/ALB ratio was higher in non-survivors than survivors (166.9 [interquartile range: 127.2-233.1] vs 214.7 [interquartile range: 160.2-309.7], P < .001). The area under the receiver-operating characteristics curve of the LDH/ALB ratio (0.642, 95% confidence interval: 0.602-0.681, P < .001) was not lower than that of other ALB-based ratios and severity scores. From multivariable logistic regression, LDH/ALB ratio was independently associated with in-hospital mortality (odds ratio = 1.001, 95% confidence interval: 1.000-1.002, P = .047). Area under the receiver-operating characteristics curves of MEDS and APACHE II scores were improved by modification with LDH/ALB ratio (MEDS: 0.643 vs 0.680, P < .001; APACHE II score: 0.675 vs 0.700, P = .003).LDH/ALB ratio may be useful as the prognostic factor in patients with severe infection requiring intensive care.

Blood Urea Nitrogen to Serum Albumin Ratio (BAR) Predicts Critical Illness in Patients with Coronavirus Disease 2019 (COVID-19)

Purpose

We sought to explore the prognostic value of blood urea nitrogen (BUN) to serum albumin ratio (BAR) and further develop a prediction model for critical illness in COVID-19 patients.

Patients and Methods

This was a retrospective, multicenter, observational study on adult hospitalized COVID-19 patients from three provinces in China between January 14 and March 9, 2020. Primary outcome was critical illness, including admission to the intensive care unit (ICU), need for invasive mechanical ventilation (IMV), or death. Clinical data were collected within 24 hours after admission to hospitals. The predictive performance of BAR was tested by multivariate logistic regression analysis and receiver operating characteristic (ROC) curve and then a nomogram was developed.

Results

A total of 1370 patients with COVID-19 were included and 113 (8.2%) patients eventually developed critical illness in the study. Baseline age (OR: 1.031, 95% CI: 1.014, 1.049), respiratory rate (OR: 1.063, 95% CI: 1.009, 1.120), unconsciousness (OR: 40.078, 95% CI: 5.992, 268.061), lymphocyte counts (OR: 0.352, 95% CI: 0.204, 0.607), total bilirubin (OR: 1.030, 95% CI: 1.001, 1.060) and BAR (OR: 1.319, 95% CI: 1.183, 1.471) were independent risk factors for critical illness. The predictive AUC of BAR was 0.821 (95% CI: 0.784, 0.858; P<0.01) and the optimal cut-off value of BAR was 3.7887 mg/g (sensitivity: 0.690, specificity: 0.786; positive predictive value: 0.225, negative predictive value: 0.966; positive likelihood ratio: 3.226, negative likelihood ratio: 0.394). The C index of nomogram including above six predictors was 0.9031125 (95% CI: 0.8720542, 0.9341708).

Conclusion

Elevated BAR at admission is an independent risk factor for critical illness of COVID-19. The novel predictive nomogram including BAR has superior predictive performance.

Relationships Between Survival and Oral Status, Swallowing Function, and Oral Intake Level in Older Patients with Aspiration Pneumonia

The factors affecting the survival of patients with aspiration pneumonia (AP) remain unclear. This study aimed to determine whether factors, including oral status, swallowing function, and oral intake level, were related to survival outcomes in older patients hospitalized for AP. The study enrolled patients with AP who were admitted to our hospital between February 2017 and November 2019. Patients were divided into two groups based on the 90-day mortality after the first swallowing function evaluation: survivors and deceased. The data were compared between the two groups. A total of 29 patients were diagnosed with AP. Of these patients, 13 died within 90 days. The numbers of patients who could not use removable dentures and required sputum suctioning and had cough reflex at rest were significantly higher in the deceased than in the survivors. The salivary pooling and pharyngeal clearance scores evaluated by videoendoscopy, International Dysphagia Diet Standardisation Initiative Functional Diet Scale score determined after swallowing function evaluation, and consciousness level were significantly worse in the deceased than in the survivors. There were significant differences in patients' oral status, swallowing function, oral intake level, and consciousness level between the survivors and deceased.

Blood Urea Nitrogen to Serum Albumin Ratio Independently Predicts Mortality in Critically Ill Patients With Acute Pulmonary Embolism

Acute pulmonary embolism (APE) is one of the prominent causes of death in patients with cardiovascular disease. Currently, reliable biomarkers to predict the prognosis of patients with APE are limited. The present study aimed to investigate the association of blood urea nitrogen to serum albumin (B/A) ratio and intensive care unit (ICU) mortality in critically ill patients with APE. A retrospective cohort study was performed using data extracted from a freely accessible critical care database (MIMIC-III). Adult (≥18 years) patients of first ICU admission with a primary diagnosis of APE in the database were enrolled in the study. The primary endpoint was the ICU mortality rate while the 28-day mortality after ICU admission was the secondary endpoint. The data of survivors and non-survivors were compared. A total of 1048 patients with APE were enrolled in this study, of which 131 patients died in ICU and 169 patients died within 28 days after ICU admission. The B/A ratio in the non-survivors group was significantly higher compared to the survivors group (P < 0.001). The multivariate analysis revealed that the B/A ratio was an independent predictor of ICU mortality (odds ratio [OR] 1.10, 95% CI 1.07-1.14, P < 0.001) and all-cause mortality within 28 days after ICU admission (hazard ratio [HR] 1.07, 95% CI 1.05-1.09, P < 0.001) in APE patients. The B/A ratio showed a greater area under the curve (AUC) of ICU mortality prediction (0.80; P < 0.001) than simplified acute physiology score II (SAPSII) (0.79), systemic inflammatory response syndrome score (SIRS) (0.62), acute physiology score III (APSIII) (0.76) and sequential organ failure assessment (SOFA) score (0.71). The B/A ratio could be a simple and useful prognostic tool to predict mortality in critically ill patients with APE.

Diagnostic Performance of a Blood Urea Nitrogen to Creatinine Ratio-based Nomogram for Predicting In-hospital Mortality in COVID-19 Patients

Background

The novel coronavirus disease (COVID-19) is leading to high morbidity and mortality. This aim of this study was to test whether blood urea nitrogen-to-creatinine ratio (BCR) is a predictor for mortality in patients with COVID-19.

Methods

Ranges of "normal" BCR values were calculated from 9165 healthy subjects, and 337 and 79 COVID-19 patients were randomly assigned to the training cohort and the validation cohort, respectively. Prognostic factor of death incidence was selected by LASSO regression analyses. The prognostic ability of BCR range was assessed by logistic regression analysis. A nomogram for predicting in-hospital mortality based on BCR was developed. The performance of the nomogram was evaluated with respect to its calibration, discrimination, and clinical usefulness.

Results

Among 337 COVID-19 patients, 13.4% and 11.3% were classified into higher and lower than normal range group, respectively. Kaplan-Meier curves for all-cause mortality showed that patients with higher BCR group had worse prognosis (P<0.0001). BCR above the normal range was independently associated with death in COVID-19 patients (OR: 7.54; 95%CI: 1.55-36.66; P=0.012). The nomogram had good discrimination in the training cohort (C-index 0.838; 0.795-0.880) and the validation cohort (C-index 0.929; 0.869-0.989), and good calibration. Using maximum Youden index, the cutoff values of 59.8 points, the sensitivity and specificity were 75.4% and 81%. Decision curve and clinical impact curve analysis demonstrated that the nomogram was clinically useful.

Conclusion

BCR was a useful prognostic factor for COVID-19 patients. Development of an individualized BCR-based prediction nomogram can effectively predict the risk of mortality and help clinicians to make individual treatment early.

Blood urea nitrogen-to-serum albumin ratio and A-DROP are useful in assessing the severity of Pneumocystis pneumonia in patients without human immunodeficiency virus infection

INTRODUCTION

There is an increasing incidence of Pneumocystis pneumonia (PcP) among individuals without human immunodeficiency virus (HIV) infection (non-HIV PcP). However, prognostic factors for patients with non-HIV PcP have not been identified. Moreover, A-DROP (for classifying the severity of community-acquired pneumonia) or the blood urea nitrogen-to-serum albumin ratio (BUN/Alb), which is reported to be a predictor of mortality of community-acquired pneumonia, has not been established as an efficient prognostic factor in patients with non-HIV PcP. In this study, we analyzed the prognostic factors for non-HIV PcP and evaluated the prognostic ability of A-DROP and the BUN/Alb ratio.

METHODS

This retrospective study involved a chart review of the medical records of 102 patients diagnosed with non-HIV PcP between January 2003 and May 2019 at five medical facilities.

RESULTS

Overall, 102 patients were involved in this study. The 30-day mortality rate for non-HIV PcP was 20.5% in this study population. Compared with survivors, non-survivors had significantly lower serum albumin levels and significantly higher age, corticosteroid dosage at the PcP onset, alveolar-arterial oxygen gradient, A-DROP score, lactate dehydrogenase levels, blood urea nitrogen levels, and BUN/Alb ratio. Multivariate analysis showed that a high BUN/Alb ratio at treatment initiation was significantly associated with 30-day mortality risk. The receiver operating characteristic curves showed that A-DROP score had the highest prognostic ability in estimating 30-day mortality.

CONCLUSIONS

In patients with non-HIV PcP, a high BUN/Alb ratio is an independent prognostic predictor of mortality risk, and A-DROP is useful for classifying the severity.

Diagnostic performance of initial blood urea nitrogen combined with D-dimer levels for predicting in-hospital mortality in COVID-19 patients

The crude mortality rate in critical pneumonia cases with coronavirus disease 2019 (COVID-19) reaches 49%. This study aimed to test whether levels of blood urea nitrogen (BUN) in combination with D-dimer were predictors of in-hospital mortality in COVID-19 patients. The clinical characteristics of 305 COVID-19 patients were analysed and were compared between the survivor and non-survivor groups. Of the 305 patients, 85 (27.9%) died and 220 (72.1%) were discharged from hospital. Compared with discharged cases, non-survivor cases were older and their BUN and D-dimer levels were significantly higher (P < 0.0001). Least absolute shrinkage and selection operator (LASSO) and multivariable Cox regression analyses identified BUN and D-dimer levels as independent risk factors for poor prognosis. Kaplan-Meier analysis showed that elevated levels of BUN and D-dimer were associated with increased mortality (log-rank, P < 0.0001). The area under the curve for BUN combined with D-dimer was 0.94 (95% CI 0.90-0.97), with a sensitivity of 85% and specificity of 91%. Based on BUN and D-dimer levels on admission, a nomogram model was developed that showed good discrimination, with a concordance index of 0.94. Together, initial BUN and D-dimer levels were associated with mortality in COVID-19 patients. The combination of BUN ≥ 4.6 mmol/L and D-dimer ≥ 0.845 μg/mL appears to identify patients at high risk of in-hospital mortality, therefore it may prove to be a powerful risk assessment tool for severe COVID-19 patients.