Laboratory test variables useful for distinguishing upper from lower gastrointestinal bleeding

Emergency medicine updates: Lower gastrointestinal bleeding

INTRODUCTION

Lower gastrointestinal bleeding (LGIB) is a condition commonly seen in the emergency department. Therefore, it is important for emergency medicine clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

OBJECTIVE

This paper evaluates key evidence-based updates concerning LGIB for the emergency clinician.

DISCUSSION

LGIB is most commonly due to diverticulosis or anorectal disease, though there are a variety of etiologies. The majority of cases resolve spontaneously, but patients can have severe bleeding resulting in hemodynamic instability. Initial evaluation should focus on patient hemodynamics, the severity of bleeding, and differentiating upper gastrointestinal bleeding from LGIB. Factors associated with LGIB include prior history of LGIB, age over 50 years, and presence of blood clots per rectum. Computed tomography angiography is the imaging modality of choice in those with severe bleeding to diagnose the source of bleeding and guide management when embolization is indicated. Among stable patients without severe bleeding, colonoscopy is the recommended modality for diagnosis and management. A transfusion threshold of 7 g/dL hemoglobin is recommended based on recent data and guidelines (8 g/dL in those with myocardial ischemia), though patients with severe bleeding and hemodynamic instability should undergo emergent transfusion. Anticoagulation reversal may be necessary. If bleeding does not resolve, embolization or endoscopic therapies are necessary. There are several risk scores that can predict the risk of adverse outcomes; however, these scores should not replace clinical judgment in determining patient disposition.

CONCLUSIONS

An understanding of literature updates can improve the care of patients with LGIB.

Plasma urea:creatinine ratio as a biomarker of gastrointestinal bleeding in dogs with anaemia

BACKGROUND

Gastrointestinal bleeding is a cause of anaemia in dogs. A reliable, non-invasive biomarker to differentiate gastrointestinal bleeding from other causes of anaemia would be advantageous to direct clinical decisions in anaemic patients. Plasma urea:creatinine ratio is an accepted biomarker of upper gastrointestinal bleeding in human medicine.

OBJECTIVES

The objective of this study was to evaluate plasma urea:creatinine ratio as a biomarker of gastrointestinal bleeding in a population of dogs with anaemia.

METHODS

This was a prospective cross-sectional study of dogs with anaemia presenting to referral centres for the investigation of anaemia. Cases were categorised as having overt gastrointestinal bleeding (melena on presentation), occult gastrointestinal bleeding (historical and diagnostic findings consistent with gastrointestinal bleeding without melena at presentation) or anaemia of other cause (confident diagnosis other than gastrointestinal bleeding reached, normal diagnostic imaging of gastrointestinal tract). Urea:creatinine ratio at presentation was calculated by dividing urea (mg/dL) by creatinine (mg/dL).

RESULTS

Ninety-five dogs were included. Plasma urea:creatinine ratio was not significantly different between dogs with overt or occult gastrointestinal bleeding or those with anaemia of other cause (median urea:creatinine ratio 25.8, 20.7 and 22.5, respectively). No significant difference in urea:creatinine ratio was found between dogs with upper and lower gastrointestinal bleeding (median urea:creatinine ratio 19.4 and 24.6, respectively).

CONCLUSIONS

Plasma urea:creatinine ratio was not helpful in differentiating between dogs with anaemia resulting from gastrointestinal bleeding (overt or occult) and those with other causes of anaemia.

Management of Patients With Acute Lower Gastrointestinal Bleeding: An Updated ACG Guideline

Acute lower gastrointestinal bleeding (LGIB) is a common reason for hospitalization in the United States and is associated with significant utilization of hospital resources, as well as considerable morbidity and mortality. These revised guidelines implement the Grading of Recommendations, Assessment, Development, and Evaluation methodology to propose recommendations for the use of risk stratification tools, thresholds for red blood cell transfusion, reversal agents for patients on anticoagulants, diagnostic testing including colonoscopy and computed tomography angiography (CTA), endoscopic therapeutic options, and management of antithrombotic medications after hospital discharge. Important changes since the previous iteration of this guideline include recommendations for the use of risk stratification tools to identify patients with LGIB at low risk of a hospital-based intervention, the role for reversal agents in patients with life-threatening LGIB on vitamin K antagonists and direct oral anticoagulants, the increasing role for CTA in patients with severe LGIB, and the management of patients who have a positive CTA. We recommend that most patients requiring inpatient colonoscopy undergo a nonurgent colonoscopy because performing an urgent colonoscopy within 24 hours of presentation has not been shown to improve important clinical outcomes such as rebleeding. Finally, we provide updated recommendations regarding resumption of antiplatelet and anticoagulant medications after cessation of LGIB.

Bleeding Complications in Uremic Patients After Ultrasound-Guided Central Venous Catheter Placement

Introduction

Bleeding associated with elevated blood urea nitrogen (BUN) is a known complication. Patients with uremia require a central venous catheter insertion by dialysis. The relation between BUN and bleeding complications during central venous catheter insertion is not yet clear.

Objective

We described the frequency of complications associated with central venous catheter implantation in uremic patients and evaluated the statistical relationship between bleeding complications and catheter type, number of punctures, and catheter insertion site. Also, we determined if any value of BUN is associated with bleeding complications.

Methods

We included patients with a serum value of BUN >70 mg/dl that required insertion of a central venous catheter. The quantitative variables were expressed through the measure of central tendency. A bivariate analysis and a ROC curve were performed.

Results

A total of 273 catheters were included in this study. Bleeding complications were detected in 69 cases (25.3%), and local bleeding was the most frequent complication in 51/69 cases. Statistically significant association was not established. We did not find a specific cut-off value directly related to BUN levels and the rate of complications.

Conclusion

Bleeding complications associated with the insertion of central venous catheter and the suspected disorder of hemostasis given by BUN levels >70 mg/dl are common. It was not possible to determine a BUN cut-off value to predict complications. The association analysis was not conclusive. High BUN levels should not be considered a high-risk condition for central venous cannulation under ultrasound guidance performed by trained personnel.

Cancer, platelet distribution width, and total protein levels as predictors of rebleeding in upper gastrointestinal bleeding

BACKGROUND

Rebleeding is associated with poor outcomes in upper gastrointestinal bleeding (UGIB). Identifying predictors of rebleeding can assist in risk assessment. The aim of the study is to investigate the factors affecting rebleeding in patients with UGIB admitted to the emergency department.

METHODS

This retrospective, observational, cross-sectional study was conducted on patients with UGIB presented to the emergency department. Patients who did not arrest in the first 24 h, who were not diagnosed with GI malignancy, and who were clinically diagnosed with UGIB were included in the study. Patient demographic characteristics, hemodynamic parameters, patient parameters, and bleeding that may affect rebleeding were evaluated. The primary endpoint was rebleeding within 7 days.

RESULTS

The study included 371 patients. A total of 55 patients (14.8%) had rebleeding within 7 days, and 62 patients (16.7%) presented without bleeding manifestations. Rebleeding rates were higher in those who presented with bloody or coffee-ground vomitus, had a diagnosis of cancer, had blood in their nasogastric tube, and had peptic ulcers due to endoscopy. Mean cell hemoglobin concentration, lymphocyte, albumin, and total protein values of patients with rebleeding were low; red blood cell distribution width, neutrophil count, platelet distribution width (PDW), and neutrophil lymphocyte ratio were high. In-hospital mortality and 30-day mortality values of patients with rebleeding were significantly increased. In the multivariate analysis, cancer, PDW, and total protein levels were statistically significant.

CONCLUSION

The presence of cancer, low total protein level, and high PDW are effective parameters in predicting 7-day rebleeding in patients with UGIB admitted to the emergency department.

Diagnostic evaluation of urea nitrogen/creatinine ratio in dogs with gastrointestinal bleeding

Background

Urea nitrogen/creatinine ratio (UCR) is a marker for upper gastrointestinal bleeding (GIB) in people.

Objectives

To assess the usefulness of UCR to predict occult GIB and distinguish upper from lower GIB in dogs.

Animals

Eighty‐nine dogs with GIB and 65 clinically healthy dogs. Dogs were grouped according to 65 overt GIB and 24 occult GIB, and based on lesion localization (37 upper, 13 lower, and 8 both).

Methods

Seventy‐four dogs were included retrospectively and 15 dogs prospectively. Serum urea nitrogen and creatinine concentrations, UCR, hemoglobin concentration, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin concentration were compared between groups. Logistic regression models were fitted to assess if variables could distinguish occult GIB from being healthy and upper from lower GIB.

Results

The UCR was significantly higher in dogs with overt GIB compared to control dogs (P = .02) and dogs with occult GIB (P = .05). The UCR was not significantly associated with occult GIB vs being healthy, or upper vs lower GIB (P > .05 each). Dogs with higher hemoglobin concentration and hematocrit had significantly lower odds of having occult GIB than being healthy (P < .0001 each).

Conclusions and Clinical Importance

The UCR does not seem to be a clinically useful marker of occult GIB and appears to have poor discriminatory ability between upper and lower GIB. An increased UCR in a dog without signs of overt GIB, especially if its hematocrit is within the middle or upper reference interval, does not appear to warrant prompt prescription of gastrointestinal protectants.

Differences in emergency endoscopy outcomes according to gastrointestinal bleeding location

BACKGROUND AND AIM

With recent technological advances in the field of endoscopic hemostasis, the prognosis of patients with gastrointestinal (GI) bleeding has improved. However, few studies have reported on the clinical course of patients with GI bleeding. This study aimed to evaluate the differences in clinical outcomes of patients with lower GI bleeding (LGIB) compared with upper GI bleeding (UGIB) and the factors related to their prognosis.

METHODS

Patients who had undergone emergency endoscopy for GI bleeding were retrospectively reviewed. The severity of GI bleeding was evaluated using the Glasgow-Blatchford (GB), AIMS65, and NOBLADS scores. Patients in whom obvious GI bleeding relapsed and/or iron deficiency anemia persisted after emergency endoscopy were considered to exhibit rebleeding.

RESULTS

We reviewed 1697 consecutive patients and divided them into UGIB (1054 patients) and LGIB (643 patients) groups. The proportion of patients with rebleeding was significantly greater in the UGIB group than in the LGIB group; the mortality rate was significantly higher in the UGIB group than in the LGIB group. Multivariate analysis showed that a GB score ≥12 and an AIMS65 score ≥2 were significantly associated with rebleeding in the UGIB group, whereas a NOBLADS score ≥4 was significantly associated with rebleeding in the LGIB group. Notably, the influence of emergency endoscopy differed according to GI bleeding location.

CONCLUSIONS

The clinical course was significantly worse in patients with UGIB than in patients with LGIB. The influence of emergency endoscopy differed according to GI bleeding location.

Blood Urea Nitrogen to Creatinine ratio in Differentiation of Upper and Lower Gastrointestinal Bleedings; a Diagnostic Accuracy Study

INTRODUCTION

Finding easily accessible and non-invasive methods for differentiating various sources of gastrointestinal (GI) bleeding before performing endoscopy and colonoscopy is of great interest. The present study was designed with the aim of evaluating the screening performance characteristics of blood urea nitrogen (BUN) to Creatinine (Cr) ratio in this regard.

METHODS

The present diagnostic accuracy study was performed on patients with acute GI bleeding presenting to emergency department from 2011 to 2016, in a retrospective manner. BUN/Cr ratio was calculated for all patients and its accuracy in differentiation of upper and lower GI bleedings, confirmed via endoscopy or colonoscopy, was evaluated.

RESULTS

A total of 621 patients with the mean age of 59.49±17.94 (5 - 93) years were studied (60.5% male). Area under the receiver operating characteristic (ROC) curve of BUN/Cr ratio for predicting the source of GI bleeding was 0.63 (95% CI: 0.57 - 0.68). Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of BUN/Cr ratio at 35 cut-off point were 19.63% (95%CI: 16.69 - 23.45), 90.16% (95%CI: 83.11 - 94.88), 89.09 (95%CI: 81.35 - 93.98), 21.53 (95%CI: 18.09 - 25.39), 8.16 (95%CI:4.76 - 13.98), and 3.65 (95%CI: 3.44 - 3.87), respectively.

CONCLUSION

Considering the relatively proper specificity and positive predictive value of BUN/Cr ratio, in cases that bleeding source cannot be determined using other non-invasive methods, values higher than 35 can predict upper GI bleeding with high probability. However, due to the low sensitivity, values less than 35 are not diagnostic.

Association between an increase in blood urea nitrogen at 24 hours and worse outcomes in acute nonvariceal upper GI bleeding

BACKGROUND AND AIMS

An increase in blood urea nitrogen (BUN) at 24 hours is a solitary and significant predictor of mortality in patients with acute pancreatitis, which may predict worse outcomes in the similarly resuscitation-requiring condition of acute nonvariceal upper GI bleeding (UGIB). The aim of our study was to assess whether an increase in BUN at 24 hours is predictive of worse clinical outcomes in acute nonvariceal UGIB.

METHODS

A retrospective cohort study including patients admitted to an academic hospital from 2004 to 2014 was conducted. An increase in BUN was defined as an increase in BUN at 24 hours of hospitalization compared with BUN at presentation. The primary outcome was a composite of inpatient death, inpatient rebleeding, need for surgical or radiologic intervention, or endoscopic reintervention. Associations between BUN change and outcomes were assessed via the Pearson χ² test and the Fisher exact test and via logistic regression for adjusted analyses.

RESULTS

There were 357 patients included in the analysis with a mean age of 64 years; 54% were men. The mean change in BUN was -10.1 mg/dL (standard deviation, 12.7 mg/dL). Patients with an increased BUN (n = 37 [10%]) were significantly more likely to experience the composite outcome (22% vs 9%, P = .014), including an increased risk of inpatient death (8% vs 1%, P = .004), compared with patients with a decreased or unchanged BUN (n = 320 [90%]). In a logistic regression model adjusting for the AIMS65 score, an increase in BUN was independently associated with an increased risk for the composite outcome (odds ratio, 2.75; P = .026).

CONCLUSION

Increasing BUN at 24 hours likely reflects under resuscitation and is a predictor of worse outcomes in patients with acute nonvariceal UGIB.

Change ratio of hemoglobin has predictive value for upper gastrointestinal bleeding

The present study aimed to identify novel predictors of upper gastrointestinal (GI) bleeding by assessing change ratios of blood test variables. Records of 1,023 patients (431 men and 592 women) who underwent endoscopy between October 2014 and September 2015 at the National Hospital Organization Shimoshizu Hospital (Yotsukaido, Japan) were retrospectively analyzed. Patients whose blood test variables for the time-point of endoscopy and three months previously were available were enrolled and subsequently categorized into a group with and another one without upper GI bleeding (n=32 and 84, respectively), and the respective change ratios were calculated for each group. One-way analysis of variance revealed that in patients with upper GI bleeding, change ratios of white blood cell count and alkaline phosphatase were significantly higher than those in patients without, while change ratios of hemoglobin (Hb), total protein and albumin were significantly reduced. Logistic regression analysis demonstrated that the change ratio of Hb was significantly correlated with upper GI bleeding. Receiver-operator characteristic analysis revealed that an 18.7% reduction of Hb was the threshold value for the prediction of upper GI bleeding. In conclusion, the present study revealed that a ≥18.7% reduction in Hb over three months has predictive value for upper GI bleeding.

Low hemoglobin levels are associated with upper gastrointestinal bleeding

Upper gastrointestinal (GI) bleeding can be fatal. Blood test variables were reviewed in search of threshold values to detect the presence of occult upper GI bleeding. The records of 1,023 patients who underwent endoscopy at the National Hospital Organization Shimoshizu Hospital from October 2014, to September 2015, were retrospectively reviewed. Of those, 95 had upper GI bleeding. One-way analysis of variance was applied to blood test variables comparing patients with and without upper GI bleeding. Logistic regression analysis was applied to detect the association of blood test parameters with upper GI bleeding, and receiver-operator characteristics were applied to establish threshold values. White blood cell count (WBC), platelet (Plt) count, and blood urea nitrogen (BUN) levels were higher, and hemoglobin (Hb) and albumin (Alb) levels were lower in patients with upper GI bleeding. Logistic regression analysis showed that low Hb was significantly associated with upper GI bleeding and a Hb value of 10.8 g/dl was established as the threshold for the diagnosis. In patients with upper GI bleeding, WBC, Plt count, and BUN levels were higher and Hb and Alb levels were reduced. Hb at 10.8 g/dl was established as a threshold value to detect upper GI bleeding.

Elevated C-reactive protein level predicts lower gastrointestinal tract bleeding

Lower gastrointestinal (GI) bleeding can be caused by colorectal polyps or cancer. The aim of the present study was to identify blood test variables and medications that can predict lower GI bleeding, which would allow for appropriate colonoscopy. The medical records of patients who underwent colonoscopy from September 2014 to September 2015 were retrospectively analyzed. The selected patients included 278 men (mean age, 67.0±11.5 years) and 249 women (mean age, 69.6±12.0 years). The diagnosis, medications, and blood test variables were compared between patients with and without bleeding. Logistic regression analysis was performed to determine the factors associated with lower GI bleeding. The presence of colorectal polyp and cancer was associated with lower GI bleeding (P=0.0044) with an odds ratio of 6.71 (P=0.0148). No lower GI bleeding was observed in patients taking non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, or anticoagulants. The C-reactive protein (CRP) levels were significantly higher in patients with lower GI bleeding (P=0.0227). The Hb levels were lower in patients with lower GI bleeding, however this finding was not statistically significant (P>0.05). No blood test variable was associated with lower GI bleeding. Elevated CRP was associated with lower GI bleeding, while there was no association between the medications and lower GI bleeding.