What is the most appropriate management for an unstable patient with lower gastrointestinal (GI) bleeding, hypotension, and diffuse abdominal tenderness despite blood transfusion?

Management of Unstable Lower GI Bleeding with Diffuse Abdominal Tenderness

In this unstable patient with lower GI bleeding, diffuse abdominal tenderness, and persistent hypotension despite blood transfusion, CT angiography should be performed immediately to localize the bleeding source before any therapeutic intervention. 1, 2

Critical Initial Assessment

This patient has a shock index >1 (calculated as heart rate/systolic BP), which defines hemodynamic instability and predicts poor outcomes. 1 The presence of diffuse abdominal tenderness raises concern for either:

• Ischemic colitis
• Perforation
• Massive intraperitoneal bleeding
• Upper GI source with peritoneal irritation

1

Why CT Angiography is the Correct Answer (Option B)

CT angiography provides the fastest and least invasive means to localize bleeding in unstable patients, with sensitivity of 79-95% and specificity of 95-100%. 1 The British Society of Gastroenterology explicitly states that CTA should be performed in preference to colonoscopy when shock index >1 after initial resuscitation. 1, 2

Key advantages in this unstable patient:

• No bowel preparation required (unlike colonoscopy) 1
• Can identify upper GI, small bowel, or colonic sources simultaneously 1
• Rapidly accessible in most hospitals with CT capability 1
• Guides subsequent intervention (angiographic embolization or surgery) 1, 2
• Can detect extravasation at bleeding rates as low as 0.3-1.0 mL/min 1

Why the Other Options Are Incorrect

Laparotomy (Option A) - WRONG

No patient should proceed to emergency laparotomy unless every effort has been made to localize bleeding by radiological and/or endoscopic modalities. 1, 2 The British Society of Gastroenterology states this as a strong recommendation. 1 Blind laparotomy without localization leads to:

• High morbidity and mortality
• Potential for unnecessary bowel resection
• Failure to identify the bleeding source in up to 50% of cases

1, 2

Surgery is reserved only for patients who fail angiographic intervention or continue to deteriorate despite all attempts at localization. 2

Urgent Colonoscopy (Option C) - WRONG

Colonoscopy is explicitly contraindicated as the initial approach in patients with shock index >1 or ongoing hemodynamic instability. 1, 2 The reasons include:

• Requires bowel preparation, which this patient cannot tolerate 1
• Cannot identify upper GI or small bowel sources 1
• Increased risk of perforation in unstable patients 1
• Delays definitive intervention 2

Colonoscopy should only be performed after successful localization and stabilization via angiography. 2

Blood Transfusion (Option D) - WRONG

While blood transfusion is essential, it is not the "most appropriate management" because it does not address source control. 1 This patient has already received blood transfusion and remains unstable (BP 70/50), indicating ongoing hemorrhage requiring immediate localization and intervention. 1, 2

The restrictive transfusion threshold (Hb trigger 70 g/L for patients without cardiovascular disease, 80 g/L with cardiovascular disease) should be used, but transfusion alone without stopping the bleeding will not save this patient. 1

Algorithmic Approach for This Patient

1. Continue aggressive resuscitation with blood products while simultaneously arranging imaging 1, 2
2. Perform CT angiography immediately to localize bleeding source 1, 2
3. If CTA is positive, proceed to catheter angiography with embolization within 60 minutes 1, 2
4. If no lower GI source identified, perform upper endoscopy to exclude upper GI bleeding (10-15% of patients with hematochezia and instability have upper GI sources) 1
5. If angiographic embolization fails or patient continues to deteriorate, then proceed to surgery with precise localization 1, 2

Critical Pitfalls to Avoid

• Do not delay imaging for further resuscitation - stabilize and image simultaneously 2
• Do not proceed directly to colonoscopy in unstable patients - this increases mortality 1, 2
• Do not perform blind laparotomy without localization attempts 1, 2
• Remember that diffuse abdominal tenderness may indicate an upper GI source with peritoneal irritation, so upper endoscopy should follow if CTA shows no lower GI source 1

Mortality Context

Mortality in lower GI bleeding is generally related to comorbidity rather than exsanguination, with overall in-hospital mortality of 3.4%, but this rises to 20% in patients requiring ≥4 units of red cells. 1, 2 This patient's persistent instability despite transfusion places her in the highest risk category, making rapid source localization via CTA absolutely critical. 2