How to differentiate spontaneous intramural intestinal hemorrhage from acute mesenteric ischemia

Abstract

Objects

The purpose of our study was to assess the diagnostic values of laboratory tests to differentiate spontaneous intramural intestinal hemorrhage (SIIH) from acute mesenteric ischemia (AMI) after abdominal computed tomography (CT) survey in the emergency department (ED).

Method

We retrospectively included 76 patients diagnosed SIIH or AMI after abdominal CT.

Results

The mean ages of 28 SIIH patients and 48 AMI patients were 75.9 ± 13.7 years and 75.8 ± 11.6 years, respectively. Patients with SIIH had significantly higher rate of Coumadin use (P < .001) and localized tenderness (P < .05). In laboratory findings, SIIH patients had prolonged prothrombin time (PT) (83.6 ± 30.0 vs. 13.4 ± 3.2, P < .001), lower blood urea nitrogen (P < .05), lower creatinine (P < .05), and lower creatine kinase (P < .05). Prolonged PT showed good discriminative value to differentiate acute abdomen patients with SIIH from AMI after abdominal CT, with an area under the receiver operating characteristic curve of 0.980 (95% confidence interval, 0.918-0.998; P < .0001). Prolonged PT cut-off value of ≧ 22.5 seconds had a sensitivity of 92.9% and a specificity of 100%. Logistic regression analysis identified prolonged PT as an independent predictor of SIIH (odds ratio, OR, 22.2; P = .007).

Conclusion

Abdominal pain patients with either SIIH or AMI are rare in the ED, but abdominal CT sometimes cannot help to differentiate them due to similar CT findings. Prolonged PT might help emergency physicians and surgeons differentiate SIIH from AMI in such cases.

Introduction

Spontaneous intramural intestinal hemorrhage (SIIH) and acute mesenteric ischemia (AMI) are difficult to differentiate by clinical or computed tomography (CT) characteristics. The symptoms and signs of both are nonspecific. Due to the high rate of peritonitis, emergency physicians (EPs) usually use abdominal CT to exclude the need for surgical intervention [1]. Unfortunately, abdominal CT cannot differentiate SIIH from AMI due to similar findings, such as homogeneous bowel wall thickening or presence of a target sign on intravenous contrast-enhanced studies [2], [3], [4]. EPs have to differentiate them in timely manner because treatments for them are significantly different: SIIH has conservative treatment [5], [6], [7], [8] and AMI has emergent surgery [9], [10]. In the past, about 14.3% to 33.3% of SIIH patients accepted laparoscopy or exploratory operation [8], [11], [12]. When abdominal CT cannot help EPs to differentiate acute abdomen patients with SIIH from those with AMI, other clinical parameters are needed to differentiate them.

Various abnormal elevated laboratory parameters such as white cell count, serum lactate concentration, or amylase activity have been assayed in AMI [9], [10], but no clinically useful results have been obtained to diagnose the AMI or differentiate from non-AMI [13], [14], [15]. Prothrombin time (PT) is the most widely used laboratory assay of coagulation factor activity, and prolonged PT occurs in 50% to 70% of patients with sepsis [16]. Possibly due to severity of AMI or sepsis, prolonged PT has been noted in AMI [17], [18]. PT appears also obviously increased in SIIH, with therapeutic or supratherapeutic levels due to warfarin treatment [11], [12]. All the above parameters have been previously evaluated in SIIH or AMI patients separately, but none of them have yet been compared between SIIH and AMI patients. For EPs, it is really a challenge when the abdominal CT reports cannot differentiate acute abdomen patients with SIIH from those with AMI, and it is suggested that EPs differentiate them by clinical presentation and laboratory tests. The purpose of our study was to evaluate acute abdomen patients with SIIH or AMI after abdominal CT survey in emergency department (ED) and assess the diagnostic values of laboratory tests to help EPs differentiate SIIH from AMI.