Background: The test characteristics of blood urea concentration in the identification of upper gastrointestinal bleeding (UGIB) or high-risk endoscopic lesions have not been clearly determined. This study aimed to elucidate if urea independently correlates with the presence of positive endoscopic findings in cases of presumed UGIB and understand the diagnostic value of this parameter when assessing a patient with potential UGIB. Methods: A retrospective cohort study was conducted at Hamilton Health Sciences hospitals examining patients who had upper endoscopy for presumed UGIB. Contingency tables were generated to determine the test characteristics of urea at different thresholds for prediction of UGIB. A crude OR was calculated for odds of bleeding being identified on endoscopy based on varying thresholds of urea, and adjusted ORs were calculated using logistic regression modelling. Results: Variables significantly associated with detecting a source of GI bleeding at endoscopy included increase in urea (OR 1.06, 95% CI 1.01–1.09), male gender (OR 2.02, 95% CI 1.08–3.77), presence of melena (OR 2.37, 95% CI 1.06–5.33), and hematemesis (OR 3.88, 95% CI 1.70–8.83), when adjusted for other covariates. The odds of identifying UGIB at endoscopy in patients with urea ≥10 mmol/L was 3.73 (95% CI 1.90–7.31) times higher than for patients with urea <10 mmol/L. Conclusion: Urea level is an independent predictor of positive endoscopic findings in presumed UGIB, and urea ≥10 mmol/L may be a useful threshold to help guide clinicians towards clinically significant bleeding that could warrant early endoscopic evaluation.

Keywords:
Urea, Upper gastrointestinal bleeding, High-risk, Endoscopy
1.
Leontiadis GI, Sreedharan A, Dorward S, Barton P, Delaney B, Howden CW, et al. Systematic reviews of the clinical effectiveness and cost-effectiveness of proton pump inhibitors in acute upper gastrointestinal bleeding. Health Technol Assess. 2007 Dec;11(51):iii–iv.
2.
Rockall TA, Logan RF, Devlin HB, Northfield TC. Incidence of and mortality from acute upper gastrointestinal haemorrhage in the United Kingdom. Steering Committee and members of the National Audit of Acute Upper Gastrointestinal Haemorrhage. BMJ. 1995 Jul;311(6999):222–6.
3.
Blatchford O, Davidson LA, Murray WR, Blatchford M, Pell J. Acute upper gastrointestinal haemorrhage in west of Scotland: case ascertainment study. BMJ. 1997 Aug;315(7107):510–4.
4.
El-Tawil AM. Trends on gastrointestinal bleeding and mortality: where are we standing? World J Gastroenterol. 2012 Mar;18(11):1154–8.
5.
Gilbert DA. Epidemiology of upper gastrointestinal bleeding. Gastrointest Endosc. 1990 Sep-Oct;36(5 suppl):S8–13.
6.
Laine LA. Helicobacter pylori and complicated ulcer disease. Am J Med. 1996 May;100(5A):52S–7S.
7.
Sharara AI, Rockey DC. Gastroesophageal variceal hemorrhage. N Engl J Med. 2001 Aug;345(9):669–81.
8.
Grace ND, Groszmann RJ, Garcia-Tsao G, Burroughs AK, Pagliaro L, Makuch RW, et al. Portal hypertension and variceal bleeding: an AASLD single topic symposium. Hepatology. 1998 Sep;28(3):868–80.
9.
Chak A, Cooper GS, Lloyd LE, Kolz CS, Barnhart BA, Wong RC. Effectiveness of endoscopy in patients admitted to the intensive care unit with upper GI hemorrhage. Gastrointest Endosc. 2001 Jan;53(1):6–13.
10.
Lin HJ, Wang K, Perng CL, Chua RT, Lee FY, Lee CH, et al. Early or delayed endoscopy for patients with peptic ulcer bleeding. A prospective randomized study. J Clin Gastroenterol. 1996 Jun;22(4):267–71.
11.
Hwang JH, Fisher DA, Ben-Menachem T, Chandrasekhara V, Chathadi K, Decker GA, et al.; Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy. The role of endoscopy in the management of acute non-variceal upper GI bleeding. Gastrointest Endosc. 2012 Jun;75(6):1132–8.
12.
Blatchford O, Murray WR, Blatchford M. A risk score to predict need for treatment for upper-gastrointestinal haemorrhage. Lancet. 2000 Oct;356(9238):1318–21.
13.
Barkun AN, Bardou M, Kuipers EJ, Sung J, Hunt RH, Martel M, et al.; International Consensus Upper Gastrointestinal Bleeding Conference Group. International consensus recommendations on the management of patients with nonvariceal upper gastrointestinal bleeding. Ann Intern Med. 2010 Jan;152(2):101–13.
14.
Chen IC, Hung MS, Chiu TF, Chen JC, Hsiao CT. Risk scoring systems to predict need for clinical intervention for patients with nonvariceal upper gastrointestinal tract bleeding. Am J Emerg Med. 2007 Sep;25(7):774–9.
15.
Srirajaskanthan R, Conn R, Bulwer C, Irving P. The Glasgow Blatchford scoring system enables accurate risk stratification of patients with upper gastrointestinal haemorrhage. Int J Clin Pract. 2010 Jun;64(7):868–74.
16.
Stanley AJ, Ashley D, Dalton HR, Mowat C, Gaya DR, Thompson E, et al. Outpatient management of patients with low-risk upper-gastrointestinal haemorrhage: multicentre validation and prospective evaluation. Lancet. 2009 Jan;373(9657):42–7.
17.
Masaoka T, Suzuki H, Hori S, Aikawa N, Hibi T. Blatchford scoring system is a useful scoring system for detecting patients with upper gastrointestinal bleeding who do not need endoscopic intervention. J -Gastroenterol Hepatol. 2007 Sep;22(9):1404–8.
18.
Al-Naamani K, Alzadjali N, Barkun AN, Fallone CA. Does blood urea nitrogen level predict severity and high-risk endoscopic lesions in patients with nonvariceal upper gastrointestinal bleeding? Can J Gastroenterol. 2008 Apr;22(4):399–403.
19.
Mukaka MM. Statistics corner: A guide to appropriate use of correlation coefficient in medical research. Malawi Med J. 2012 Sep;24(3):69–71.
20.
Swets JA. ROC analysis applied to the evaluation of medical imaging techniques. Invest Radiol. 1979 Mar-Apr;14(2):109–21.
21.
Tomizawa M, Shinozaki F, Hasegawa R, Shirai Y, Motoyoshi Y, Sugiyama T, et al. Patient characteristics with high or low blood urea nitrogen in upper gastrointestinal bleeding. World J Gastroenterol. 2015 Jun;21(24):7500–5.
22.
Chung IK. Predictive factors for endoscopic hemostasis in patients with upper gastrointestinal bleeding. Clin Endosc. 2014 Mar;47(2):121–3.
23.
Srygley FD, Gerardo CJ, Tran T, Fisher DA. Does this patient have a severe upper gastrointestinal bleed? JAMA. 2012 Mar;307(10):1072–9.
24.
Kumar NL, Claggett BL, Cohen AJ, Nayor J, Saltzman JR. Association between an increase in blood urea nitrogen at 24 hours and worse outcomes in acute nonvariceal upper GI bleeding. Gastrointest Endosc. 2017 Dec;86(6):1022–1027.e1.
25.
Laursen SB, Hansen JM, Schaffalitzky de Muckadell OB. The Glasgow Blatchford score is the most accurate assessment of patients with upper gastrointestinal hemorrhage. Clin Gastroenterol Hepatol. 2012 Oct;10(10):1130–1135.e1.
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2019
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