What is the most appropriate initial management for a 68-year-old man with hypertension and colorectal polyps who presents to the emergency department with acute bright red rectal bleeding, pallor, hypertension (blood pressure 160/90 mmHg) and tachycardia (heart rate 110 bpm)?

Immediate Management of Acute Lower GI Bleeding with Hemodynamic Instability

The most appropriate initial management is B- IV fluid and blood transfusion to achieve hemodynamic stabilization before any diagnostic procedures. 1, 2

Immediate Resuscitation Protocol

Establish two large-bore peripheral IV lines immediately and begin aggressive crystalloid infusion (1-2 L of normal saline or balanced crystalloids) to restore intravascular volume. 1, 3

Hemodynamic Targets During Resuscitation

• Target mean arterial pressure >65 mmHg during the resuscitation phase 1, 2
• Maintain urine output ≥30 mL/hour via urinary catheter as an indicator of adequate perfusion 1
• Monitor continuously for heart rate <100 bpm and systolic blood pressure >100 mmHg as markers of stability 1

Blood Transfusion Strategy

In this 68-year-old patient with cardiovascular risk factors (hypertension) presenting with pallor and tachycardia, transfuse packed red blood cells to maintain hemoglobin >10 g/dL. 1, 2

• The higher transfusion threshold is specifically recommended for elderly patients with cardiovascular comorbidities, rather than the standard >7 g/dL target used in younger patients without cardiac disease 1, 2
• Perform immediate blood typing and cross-matching to enable rapid transfusion 3

Critical Timing Consideration

Hemodynamic stabilization must be achieved BEFORE any diagnostic procedures including colonoscopy or CT angiography. 1, 3, 2

• Performing colonoscopy in an unstable patient markedly increases the risk of aspiration, cardiovascular events, and mortality 1
• Endoscopic evaluation should be postponed until hemodynamic stability is achieved, then performed within 24 hours after adequate resuscitation 1, 3

Why CT Angiography is NOT the Initial Step

CT angiography is a diagnostic procedure that should only be considered after hemodynamic stabilization has been achieved through IV fluids and blood products. 1, 2 The patient's tachycardia (HR 110) and pallor indicate active bleeding with hemodynamic compromise requiring immediate resuscitation, not diagnostic imaging.

Algorithmic Approach

1. Immediate IV access (two large-bore lines) and begin crystalloid infusion 1, 3
2. Transfuse packed red blood cells targeting hemoglobin >10 g/dL given age and hypertension 1, 2
3. Monitor hemodynamic parameters (MAP >65 mmHg, HR <100 bpm, urine output ≥30 mL/h) 1
4. Once stabilized, proceed to colonoscopy within 24 hours to identify bleeding source (likely colorectal polyps in this patient) 1, 3

Special Consideration for This Patient

Given the history of colorectal polyps, the bleeding source is likely colonic. However, approximately 10-15% of patients presenting with bright red rectal bleeding have an upper GI source, so upper endoscopy should be considered if colonoscopy does not identify a bleeding source. 3

Common Pitfall to Avoid

Avoid fluid overload during resuscitation, which can exacerbate bleeding and worsen outcomes. 1, 2 Use balanced crystalloids when feasible as they are associated with lower mortality compared to normal saline. 1