Diagnosing Upper Gastrointestinal Bleeding: Essential Tests and Procedures

When a patient presents with symptoms of upper gastrointestinal (GI) bleeding, prompt and accurate diagnosis is crucial. A variety of diagnostic tools and laboratory assessments are used to identify the source of bleeding, assess severity, and guide treatment decisions. Understanding these tests can help both patients and medical professionals make informed choices regarding care and management.

Laboratory Tests for GI Bleeding

Blood Count Analysis

In the early stages of bleeding, hemoglobin levels, red blood cell count, and hematocrit may appear normal. However, within 3–4 hours after the onset of bleeding, due to fluid replacement therapy or natural compensatory mechanisms, these values may decrease due to dilution. Additionally, white blood cell counts often rise to 10–20×10⁹/L within 2–5 hours following a major bleed and typically return to normal within 2–3 days after the bleeding stops.

Kidney Function Assessment

As the body processes hemoglobin from the blood loss, glomerular filtration may decrease, resulting in elevated blood urea nitrogen (BUN) levels. These levels peak within 24–48 hours and usually normalize within 3–4 days. A BUN-to-creatinine ratio greater than 25:1 is often indicative of upper GI bleeding.

Liver Function Evaluation

Some patients may also show increased bilirubin and liver enzyme levels, which could indicate underlying liver disease or stress from the bleeding event.

Stool Testing

A positive fecal occult blood test directly confirms the presence of gastrointestinal bleeding, making it a valuable initial diagnostic tool.

Endoscopic Examination

Upper Endoscopy as First-line Diagnosis

Esophagogastroduodenoscopy (EGD), or upper endoscopy, is the gold standard for diagnosing and managing upper GI bleeding. Once a patient's vital signs are stable, the procedure should be performed within 24 hours of presentation. Early endoscopic evaluation significantly reduces mortality, the need for surgery, and the risk of rebleeding, while also shortening hospital stays.

Capsule Endoscopy and Enteroscopy

Capsule endoscopy is increasingly used as a first-line tool for visualizing the upper GI tract and small intestine. It can be performed during both active and quiescent phases of bleeding, with a diagnostic yield of approximately 60–70% for small bowel lesions. If abnormalities are detected, push enteroscopy can be used for further investigation or therapeutic intervention.

Imaging Techniques

Barium Studies

While barium X-rays can help identify structural abnormalities, they are typically performed after bleeding has stopped and the patient is stable. Due to the rapid healing of some lesions like acute gastric mucosal injury or small ulcers, the sensitivity of this test is relatively low.

CT and CT Angiography

CT scanning, particularly with angiographic capabilities, has become a preferred imaging method for evaluating acute GI bleeding. With an accuracy rate of up to 98%, CT provides a non-invasive, fast, and widely available diagnostic option. A full triphasic CT scan (non-contrast, arterial, and portal venous phases) offers comprehensive data to help pinpoint the source of upper GI bleeding.

Selective Angiography

This procedure is especially useful in cases of obscure or recurrent bleeding. It is often the first choice for patients experiencing massive bleeding who are hemodynamically unstable and unable to undergo endoscopy. Angiography not only helps locate the source of bleeding but also allows for therapeutic embolization during the same session.

Nuclear Medicine Scans

Using technetium-99m labeled red blood cells, nuclear scans can detect active bleeding even when endoscopic visualization is challenging. This technique is particularly helpful when endoscopy fails to identify the bleeding site but signs of ongoing hemorrhage persist.

Surgical Exploration

When All Else Fails

If non-invasive and minimally invasive techniques fail to locate the bleeding source, and the patient continues to experience life-threatening hemorrhage, surgical exploration may be necessary. Intraoperative endoscopy can be a valuable tool during surgery to identify subtle or elusive vascular lesions that may be causing the bleeding.