The association between blood urea nitrogen to creatinine ratio and mortality in patients with upper gastrointestinal bleeding

Abstract

Background and study aims: Azotaemia is commonly identified among patients with upper gastrointestinal bleeding (UGIB) due to absorption of blood products in the small bowel. Previous studies have found blood urea nitrogen-to-creatinine (BUN/Cr) ratio to be significantly elevated among patients UGIB bleeding compared to patients with lower GI bleeding. However, no studies have explored the relationship between BUN/Cr ratio and mortality. This study is aimed at investigating how BUN/Cr ratio relates to outcomes for UGIB patients.

Patients and methods: This study was conducted prospectively at a university-affiliated teaching hospital with approximate 70,000 annual emergency department (ED) visits. Data from a total of 258 adult UGIB patients were collected between March 1, 2011 and March 1, 2012. Cox regression analysis was used to identify risk factors for 30-day mortality.

Results: Malignancy and Rockall score were associated with increased risk of 30-day mortality (Unadjusted hazard ratio (HR): 3.87, 95% CI: 1.59-9.41, p = 0.0029; HR: 1.31, 95% CI: 1.02-1.71, p = 0.0476, respectively). However, BUN/Cr > 30 was associated with lower risk of 30-day mortality (HR: 0.32, 95% CI: 0.11-0.97, p = 0.0441).

Conclusions: A BUN/Cr ratio of >30 was found to be an independent risk factor for mortality and may be useful for pre-endoscopic assessment. Development of future risk scoring systems might warrant consideration of including BUN/Cr ratio as a parameter for estimating risk.

Keywords: BUN/Cr; Blood urea nitrogen to creatinine ratio; UGIB; Upper gastrointestinal bleeding.