What is the most appropriate management for an unstable patient with lower gastrointestinal (GI) bleeding, hypotension, and a diffusely tender abdomen?

Management of Hemodynamically Unstable Lower GI Bleeding with Diffuse Abdominal Tenderness

In this unstable patient with lower GI bleeding, diffuse abdominal tenderness, and persistent hypotension despite resuscitation (BP 70/50), the most appropriate management is immediate CT angiography (CTA) followed by angiographic embolization, NOT laparotomy or colonoscopy. 1, 2

Critical Clinical Context

This patient presents with two concerning features that fundamentally alter the management approach:

• Hemodynamic instability (shock index = HR/70 = >1, indicating true shock) 1, 2
• Diffuse abdominal tenderness (suggesting possible ischemia, perforation, or infarction) 3

Immediate Management Algorithm

Step 1: Aggressive Resuscitation

• Continue aggressive fluid resuscitation with crystalloids and blood products 2, 4
• Use restrictive transfusion thresholds: Hb trigger 70 g/L (target 70-90 g/L) for patients without cardiovascular disease, or Hb trigger 80 g/L (target ≥100 g/L) for those with cardiovascular disease 1, 2
• Reverse any coagulopathy immediately with prothrombin complex concentrate and vitamin K if on warfarin 1, 2

Step 2: Immediate CT Angiography

CTA should be performed immediately as the first diagnostic step because it:

• Provides the fastest and least invasive means to localize bleeding in unstable patients 1, 2
• Allows for immediate treatment planning without the risks of colonoscopy in an unstable patient 1
• Can identify both bleeding sources AND complications like ischemia or perforation that may explain the diffuse tenderness 1, 2

Step 3: Angiographic Embolization

• Following positive CTA, proceed to catheter angiography with embolization within 60 minutes 1, 2
• This approach maximizes success rates in hemodynamically unstable patients 1

Step 4: Surgery - Only as Last Resort

Laparotomy should be avoided unless:

• The patient remains unstable despite aggressive resuscitation AND all attempts at localization and angiographic intervention have failed 3, 1
• There is evidence of colonic infarction requiring urgent surgery (which the diffuse tenderness may suggest, but must be confirmed) 3
• An aortoenteric fistula is suspected (rare exception where direct surgery may be justified) 3

Why NOT Colonoscopy?

Colonoscopy is explicitly contraindicated in this scenario because:

• The British Society of Gastroenterology specifically recommends against colonoscopy when shock index >1 or patients remain unstable after resuscitation 1
• Colonoscopy requires bowel preparation, which this unstable patient cannot tolerate 1, 5
• The procedure carries significant risks in hemodynamically unstable patients 1
• Colonoscopy is reserved for stable patients or after successful stabilization via angiography 1

Why NOT Immediate Laparotomy?

Proceeding directly to laparotomy without localization is associated with extremely poor outcomes:

• Emergency subtotal colectomy without localization has mortality rates of 27-57% 3
• Blind segmental resection has rebleeding rates as high as 33% and mortality rates of 30-57% 3
• The British Society of Gastroenterology explicitly states that laparotomy without localization should be avoided given the well-established high-risk profile 3
• Overall operative mortality for emergency surgery in lower GI bleeding is 10%, but rises dramatically with age and comorbidity 3

Critical Caveat: The Diffuse Abdominal Tenderness

The diffuse abdominal tenderness raises concern for:

• Colonic ischemia with infarction - which may require urgent surgery 3
• Perforation - which would mandate immediate surgery
• Peritonitis from another cause

However, CTA will rapidly identify these surgical emergencies while simultaneously localizing the bleeding source 1, 2. If CTA demonstrates free air, pneumatosis, or frank infarction, then immediate laparotomy becomes necessary 3. But this determination must be made WITH localization, not blindly 3, 1.

Mortality Context

It's crucial to understand that mortality in lower GI bleeding is generally related to comorbidity rather than exsanguination, with overall in-hospital mortality of 3.4%, rising to 20% in patients requiring ≥4 units of red cells 1, 2. The elderly patient's age and comorbidities likely pose greater mortality risk than the bleeding itself 3, 6.

Answer to the Question

B. Angiography (preceded by CTA) is the correct answer. This represents the modern, evidence-based approach that prioritizes rapid localization followed by minimally invasive intervention, reserving surgery only for patients who fail all other measures or have confirmed surgical emergencies identified on imaging 1, 2.