In a 68-year-old hypertensive man with known colorectal polyps presenting with acute bright‑red rectal bleeding, pallor, tachycardia and hypertension, what is the most appropriate immediate management: urgent colonoscopy, intravenous fluid and blood transfusion, or CT angiography?

Immediate Management of Acute Lower GI Bleeding with Hemodynamic Compromise

The most appropriate immediate management is B: IV fluid and blood transfusion to achieve hemodynamic stabilization before any diagnostic procedure. 1

Rationale for Prioritizing Resuscitation

This 68-year-old patient presents with clear signs of hemodynamic compromise—tachycardia (HR 110 bpm), pallor suggesting acute anemia, and bright red rectal bleeding—despite a preserved blood pressure. 1 Initial resuscitation and hemodynamic stabilization are critical, and the patient's condition must be optimized before any endoscopic or radiologic intervention. 2, 1

Why Not Urgent Colonoscopy First?

• Performing colonoscopy in a hemodynamically unstable patient markedly increases the risk of aspiration, cardiovascular events, and mortality. 1
• Colonoscopy must be deferred until hemodynamic stability is achieved, defined as heart rate <100 bpm, systolic blood pressure >100 mmHg, MAP >65 mmHg, and adequate hemoglobin levels. 1
• Once stabilized, colonoscopy should be performed within 24 hours after adequate bowel preparation, as it remains the gold-standard diagnostic and therapeutic modality for lower GI bleeding. 1, 3, 4

Why Not CT Angiography First?

• CT angiography must be deferred until the patient meets hemodynamic stabilization criteria; performing it in an unstable patient markedly increases the risk of cardiovascular collapse. 1
• CT angiography can detect active bleeding only when the bleeding rate exceeds approximately 0.5 mL/min and requires hemodynamic stability to obtain diagnostic images. 1
• CT angiography is employed as a secondary diagnostic tool in hemodynamically stable patients with ongoing bleeding after initial resuscitation when colonoscopy is nondiagnostic. 1

Immediate Resuscitation Protocol

Vascular Access and Fluid Therapy

• Obtain two large-bore peripheral intravenous lines immediately (preferably in the ante-cubital fossae) to allow rapid infusion of crystalloids. 1, 3
• Administer 1–2 L of isotonic crystalloid solution (normal saline or balanced crystalloids) quickly to correct intravascular volume depletion. 1, 4
• Balanced crystalloid solutions are preferred when feasible because they are associated with lower mortality. 1

Hemodynamic Targets

• Target a mean arterial pressure (MAP) >65 mmHg during the resuscitation phase while avoiding fluid overload, which can exacerbate bleeding. 2, 1, 4
• Monitor heart rate, blood pressure, and oxygen saturation continuously throughout resuscitation. 1
• Insert a urinary catheter and target urine output ≥30 mL/hour as an objective marker of adequate renal perfusion. 1

Blood Transfusion Strategy

• Transfuse packed red blood cells to maintain hemoglobin ≥10 g/dL in this elderly patient with cardiovascular comorbidities (hypertension). 1
• In older adults with cardiovascular risk factors, a higher transfusion threshold is recommended compared to the general population (where hemoglobin >7 g/dL is acceptable). 1, 4
• Perform immediate blood typing and cross-matching to enable rapid transfusion. 3, 4

Coagulopathy Management

• Correct coagulopathy with fresh-frozen plasma if the international normalized ratio (INR) exceeds 1.5. 1
• If the patient is on anticoagulation, reverse with prothrombin complex concentrate and vitamin K in cases of unstable gastrointestinal hemorrhage. 4

Algorithmic Approach to Stabilization

1. Immediate assessment: Check vital signs, assess for signs of shock (tachycardia, pallor, hypotension). 1, 3
2. Establish IV access: Place two large-bore peripheral lines. 1, 3
3. Begin crystalloid infusion: Administer 1–2 L rapidly, targeting MAP >65 mmHg. 1, 4
4. Transfuse packed red blood cells: Maintain hemoglobin ≥10 g/dL given age and hypertension. 1
5. Monitor resuscitation endpoints: Heart rate <100 bpm, systolic BP >100 mmHg, MAP >65 mmHg, urine output ≥30 mL/h. 1
6. Once stable, proceed to colonoscopy within 24 hours after adequate bowel preparation. 1, 3, 4

Common Pitfalls to Avoid

• Delaying resuscitation to perform diagnostic procedures: Stabilization takes absolute priority over diagnosis. 3
• Excessive crystalloid administration: Avoid fluid overload, which can worsen bleeding and increase portal pressure in patients with underlying liver disease. 2, 1
• Performing endoscopy or imaging before achieving stability: This dramatically increases procedural complications and mortality. 1
• Under-transfusing elderly patients with cardiovascular disease: This population requires higher hemoglobin targets than younger, healthier patients. 1, 4

Special Consideration: Known Colorectal Polyps

While this patient has known colorectal polyps (a likely bleeding source), the presence of a suspected source does not change the priority of resuscitation before diagnostic evaluation. 1 The polyps may be the culprit, but colonoscopy to identify and treat the specific bleeding lesion must wait until hemodynamic stability is achieved. 1, 3