Published online May 28, 2015. doi: 10.3748/wjg.v21.i20.6246
Peer-review started: November 7, 2014
First decision: December 11, 2014
Revised: December 18, 2014
Accepted: January 21, 2015
Article in press: January 21, 2015
Published online: May 28, 2015
AIM: To distinguish upper from lower gastrointestinal (GI) bleeding.
METHODS: Patient records between April 2011 and March 2014 were analyzed retrospectively (3296 upper endoscopy, and 1520 colonoscopy). Seventy-six patients had upper GI bleeding (Upper group) and 65 had lower GI bleeding (Lower group). Variables were compared between the groups using one-way analysis of variance. Logistic regression was performed to identify variables significantly associated with the diagnosis of upper vs lower GI bleeding. Receiver-operator characteristic (ROC) analysis was performed to determine the threshold value that could distinguish upper from lower GI bleeding.
RESULTS: Hemoglobin (P = 0.023), total protein (P = 0.0002), and lactate dehydrogenase (P = 0.009) were significantly lower in the Upper group than in the Lower group. Blood urea nitrogen (BUN) was higher in the Upper group than in the Lower group (P = 0.0065). Logistic regression analysis revealed that BUN was most strongly associated with the diagnosis of upper vs lower GI bleeding. ROC analysis revealed a threshold BUN value of 21.0 mg/dL, with a specificity of 93.0%.
CONCLUSION: The threshold BUN value for distinguishing upper from lower GI bleeding was 21.0 mg/dL.
Core tip: Differentiation of upper vs lower gastrointestinal (GI) bleeding is crucial. Laboratory test variables were investigated for their ability to distinguish upper from lower GI bleeding from retrospective analysis. Total protein, hemoglobin, and lactate dehydrogenase were lower and blood urea nitrogen (BUN) was higher in patients with upper GI bleeding. The threshold BUN value for distinguishing upper from lower GI bleeding was 21.0 mg/dL, with a specificity of 93.0%.