In a 68-year-old hypertensive patient with known colorectal polyps presenting to the emergency department with bright red rectal bleeding, pallor, tachycardia, and a blood pressure of 160/90 mm Hg, what is the most appropriate immediate management?

Immediate Management of Acute Lower GI Bleeding with Hemodynamic Compromise

This patient requires immediate IV fluid resuscitation and blood transfusion to achieve hemodynamic stability before any diagnostic procedures. 1, 2, 3

Initial Resuscitation Protocol

The priority is aggressive volume resuscitation, not imaging. This 68-year-old patient presents with signs of hemodynamic compromise (tachycardia at 110 bpm, pallor suggesting significant anemia) despite a preserved blood pressure, which indicates compensated shock from acute blood loss. 2, 3

Immediate Actions Required:

• Establish two large-bore peripheral IV lines immediately to enable rapid crystalloid and blood product infusion 2, 4

• Begin crystalloid resuscitation with 1-2 liters of normal saline or balanced crystalloids administered rapidly to restore intravascular volume 2, 3

• Transfuse packed red blood cells to maintain hemoglobin >10 g/dL given his age (68 years) and cardiovascular risk factors (hypertension) 1, 2, 3

• Target mean arterial pressure >65 mmHg during the resuscitation phase 1, 2, 3

• Monitor urine output ≥30 mL/hour via urinary catheter as an indicator of adequate tissue perfusion 2

Why CT Angiography is NOT the Answer

CT angiography should only be performed AFTER hemodynamic stabilization, not before. 1, 4 The guidelines are explicit that diagnostic procedures must be postponed until the patient achieves stability, defined as heart rate <100 bpm, systolic BP >100 mmHg, and MAP >65 mmHg. 2

Performing diagnostic imaging in an unstable patient:

• Markedly increases risk of cardiovascular collapse, aspiration, and mortality 2
• Delays life-saving resuscitation 3
• Requires active bleeding rates >0.5 mL/min to localize a source 1

Resuscitation Targets Before Proceeding to Diagnosis

The patient must achieve these parameters before any diagnostic workup:

• Heart rate <100 bpm 2
• Systolic blood pressure >100 mmHg 2
• Mean arterial pressure >65 mmHg 1, 2, 3
• Hemoglobin >10 g/dL (given age and hypertension) 1, 2

Diagnostic Approach AFTER Stabilization

Once hemodynamically stable, the diagnostic sequence should be:

• Colonoscopy within 24 hours after adequate bowel preparation remains the gold standard for identifying the bleeding source in lower GI hemorrhage 1, 2, 4

• Consider upper endoscopy if no lower source is identified, as approximately 15% of patients with bright red rectal bleeding have an upper GI source 1, 2, 4

• CT angiography may be considered in stable patients with ongoing bleeding after initial resuscitation if endoscopy is non-diagnostic 1

Critical Pitfall to Avoid

The most dangerous error is prioritizing diagnostic procedures over resuscitation. 3 This patient's tachycardia and pallor indicate he is in compensated shock—his blood pressure is maintained through sympathetic compensation, but this will fail without immediate volume replacement. Delaying IV fluids and blood products to obtain imaging will lead to decompensation and potentially cardiovascular collapse. 2, 3

Special Consideration for This Patient

Given his history of colorectal polyps, the bleeding source is likely colonic (polyp-related bleeding or diverticular disease). However, the immediate management remains the same regardless of suspected etiology: resuscitate first, diagnose second. 1, 2, 4

Answer: B - IV fluid and blood transfusion is the most appropriate immediate management.