A 66-year-old man presents to the emergency department with melanotic stools, dizziness, and hypotension. He is admitted to the ICU, his hemoglobin and blood pressure normalize after three units of packed red blood cells, and his melena slows down. Upper GI endoscopy and colonoscopy are performed, which do not show any source of bleeding. Shortly thereafter he develops more melena and a drop in hemoglobin. A repeat endoscopy, tagged RBC study, and CT angiogram all fail to identify a bleeding source, but hemoglobin again normalizes with two more units of packed red blood cells. The following day he again develops hematochezia, with a worsening transfusion requirement and associated hypotension.
Which of the following is the next best step to managing this bleeding?
A. Continued transfusion, hold subcutaneous heparin, observeCorrect Answer: C
The general approach to GI bleeding should start with the ABCs, including confirming that the patient has large bore IV access and is in the appropriate clinical setting for close hemodynamic monitoring. Evaluation should begin with upper GI endoscopy and colonoscopy. When these tests are negative, it is possible that :
If bleeding persists a repeat endoscopy can be considered to catch an intermittent source of bleeding that may have been missed. If these are unrevealing, other diagnostic tests can be considered. GI bleeding is often intermittent, and in many cases does require multiple tests to identify and treat the site of bleeding.
The patient in this scenario has an intermittent, brisk bleed resulting in hemodynamic instability requiring continued transfusion. At this point, continued transfusion and just observing the patient is not appropriate given that the bleeding is ongoing, brisk, and now resulting in hemodynamic instability. A tagged RBC study can assist in locating slow, occult bleeds, but will only grossly localize bleeding when more brisk and will not allow intervention. It is generally not useful in hemodynamically unstable patients. Once blood pools in the small bowel, the study carries a false positive rate at downstream locations. In the patient above with a brisk bleed, a repeat tagged RBC study would be unlikely to yield new, helpful information. VCE has the potential to identify a bleeding source in the small bowel, but has many limitations. There is no way to mark the site of bleeding, the information is reviewed retrospectively, and in many cases the intestinal mucosa cannot be completely visualized. Other techniques available at some centers to evaluate the small bowel include push endoscopy, in which a pediatric endoscope is used to examine 50 to 70 cm past the ligament of treitz, or single or double balloon endoscopy that allows an endoscope to be advanced deep into the small bowel. Surgically, there is very limited ability to localize GI bleeding intraoperatively. Occasionally, intraoperative enteroscopy can also be used to look intraluminally at the small bowel but is difficult to perform and invasive. Surgery should very rarely be performed on patients with GI bleeding that is unlocalized preoperatively, as the capacity to identify the site of bleeding intraoperatively is very limited.
An angiogram has both diagnostic and therapeutic potential. A standard angiogram will demonstrate active extravasation if bleeding is greater than a rate of 0.5 mL/min. Most hemodynamically unstable patients are bleeding at this rate or higher. An angiogram can also be done in a “provocative” fashion with anticoagulants, vasodilators, and antifibrinolytics to encourage bleeding and assist with identifying the site. This does come with the risk of exacerbating hemorrhage, and a surgery team is available to assist in the event of uncontrolled hemorrhage. If the site of bleeding is identified at a focal area, embolization of the area of active extravasation can be performed. For this patient who is hemodynamically unstable and has already undergone multiple other diagnostic procedures, an angiogram gives the best chance of identifying and treating the bleeding source.
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