An 80‑year‑old woman with a massive ongoing lower gastrointestinal bleed presenting as maroon‑colored stool, who remains pale and tachycardic despite adequate fluid resuscitation and has a soft, non‑tender abdomen—what is the initial management?

Initial Management: CT Angiography

For this hemodynamically unstable 80-year-old woman with massive ongoing lower GI bleeding (maroon stool, pale, tachycardic) who continues to bleed despite resuscitation, CT angiography should be performed immediately as the initial diagnostic and localizing procedure, followed by catheter angiography with embolization. 1

Why Angiography (Answer B) is Correct

Hemodynamic Instability Dictates the Approach

• Calculate the shock index (heart rate/systolic BP): A value >1 confirms hemodynamic instability and predicts poor outcomes 1, 2
• This patient demonstrates persistent bleeding despite adequate resuscitation, which is a critical indicator that non-surgical intervention is urgently needed 3
• The American College of Radiology explicitly recommends CT angiography as the first diagnostic step in hemodynamically unstable patients, as it provides the fastest and least invasive means to localize bleeding before any therapeutic intervention 1

The Evidence Against Other Options

Colonoscopy (Option C) is contraindicated in this scenario:

• The British Society of Gastroenterology explicitly recommends against colonoscopy as the initial approach when patients have shock index >1 or remain unstable after resuscitation 1
• Colonoscopy should be reserved for stable patients or performed after successful localization and stabilization via angiography 1
• Urgent colonoscopy (<24 hours) does not improve clinical outcomes including rebleeding, mortality, or length of stay even in stable patients 1

NGT (Option A) has limited utility:

• Nasogastric lavage may be warranted if there is medium to low suspicion of an upper GI source, but can be misleading if only clear fluid without bile or blood returns 3
• While 10-15% of patients with severe hematochezia have an upper GI source 3, the maroon-colored stool and soft, non-tender abdomen make a lower GI source more likely
• NGT does not localize the bleeding source or provide therapeutic intervention

Barium enema (Option D) is obsolete:

• Barium studies have no role in acute GI bleeding management and would delay definitive diagnosis and treatment

The Correct Management Algorithm

Step 1: Immediate Resuscitation (Concurrent with Assessment)

• Continue aggressive IV fluid resuscitation targeting normalization of blood pressure and heart rate 2
• Use restrictive transfusion thresholds: Maintain hemoglobin >7 g/dL for patients without cardiovascular disease, or >8-9 g/dL for those with cardiovascular disease 1, 2
• Correct coagulopathy: Transfuse fresh frozen plasma if INR >1.5 and platelets if count <50,000/µL 3, 2

Step 2: CT Angiography (The Answer)

• Perform CT angiography immediately to rapidly localize the bleeding source 1
• CTA has a 94% positive rate in hemodynamically unstable patients with lower GI bleeding 1
• This provides the fastest localization before therapeutic intervention 1

Step 3: Catheter Angiography with Embolization

• Following positive CTA, proceed to catheter angiography with embolization within 60 minutes in centers with 24/7 interventional radiology services 1
• Transcatheter embolization provides time to stabilize the patient and prepare the bowel, both of which contribute to better surgical outcomes if surgery ultimately becomes necessary 1

Step 4: Surgery (Last Resort Only)

• Surgery should be reserved only for patients who fail angiographic intervention or continue to deteriorate despite all attempts at localization and intervention 1
• Surgical intervention is indicated when hemodynamic instability persists despite aggressive resuscitation, transfusion requirement exceeds 6 units, or severe bleeding recurs 3
• Blind segmental resection and emergency subtotal colectomy are associated with substantial rates of rebleeding (as high as 33%) and mortality (33-57%) 3, 1

Critical Pitfalls to Avoid

• Do not rush to colonoscopy in unstable patients – this delays definitive localization with CTA and potential embolization 1
• Do not proceed to surgery without attempting localization – even in hemodynamically unstable patients, localization using CTA or angiography should be attempted before surgery to allow for targeted treatment rather than blind resection 1
• Recognize the mortality context: The overall operative mortality rate for emergency surgery for lower GI bleeding is 10%, with mortality rates for total abdominal colectomy ranging from 27-33% 3, 1
• In this 80-year-old patient, age is an important risk factor for postoperative mortality (9.8% in patients aged 80-89 years) 3

Age-Specific Considerations

• Advanced age is the strongest risk factor for lower GI bleeding, with both diverticulosis and angiodysplasia increasing dramatically in patients over 60-70 years 4
• Diverticulosis accounts for 21-41% of all lower GI bleeding cases and is the single most common etiology in elderly patients 4
• 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