What is the immediate management for a patient with bleeding per rectum (PR) or abdominal aortic aneurysm (AAA) with unstable vital signs?

Immediate Management of Bleeding PR or Unstable AAA with Unstable Vitals

Immediate surgical intervention or angioembolization is required for patients with bleeding per rectum or abdominal aortic aneurysm presenting with hemodynamic instability and no or transient response to resuscitation. 1

Initial Resuscitation (First Minutes)

1. Establish IV access

   • Two large-bore IV lines (16-18G)
   • Draw blood samples (CBC, coagulation profile, type and cross)

2. Hemodynamic monitoring

   • Arterial line placement (preferably right radial artery)
   • Continuous vital sign monitoring

3. Volume resuscitation

   • Crystalloids initially with target systolic BP 80-100 mmHg (permissive hypotension) 1
   • Blood product transfusion as needed
   • Avoid over-resuscitation which may increase bleeding

4. Pharmacologic management

   • For AAA: Beta-blockers (IV propranolol, metoprolol, or esmolol) to reduce force of left ventricular ejection 1
   • Add vasodilators (sodium nitroprusside) if beta-blockers alone don't control hypertension 1
   • Pain control with IV morphine

Diagnostic Approach (First 30 Minutes)

For hemodynamically unstable patients:

• E-FAST (Extended Focused Assessment with Sonography for Trauma) to identify free fluid 1
• Bedside TTE/TEE for AAA patients to identify cardiac tamponade, aortic regurgitation 1

For patients with transient response to resuscitation:

• CT scan with IV contrast (immediate and delayed phases) if patient can be stabilized 1, 2
• One-shot IVP (2 mL/kg IV contrast with single image at 10-15 minutes) if going directly to surgery 1

Definitive Management (First Hour)

For bleeding PR with unstable vitals:

1. Identify source:

   • Consider aortoenteric fistula if history of AAA repair 3, 4
   • Rule out other causes of massive GI bleeding

2. Intervention:

   • Immediate surgery for exsanguinating hemorrhage 1
   • Angioembolization for selected patients with segmental bleeding if interventional radiology immediately available 1

For unstable AAA:

1. Endovascular repair if anatomy suitable and patient can be briefly stabilized 2, 5

   • Lower 30-day mortality compared to open repair (21% vs 34%)
   • Consider local anesthesia over general anesthesia

2. Open surgical repair if:

   • Anatomy unsuitable for endovascular approach
   • Patient too unstable for CT imaging
   • Facilities for endovascular repair unavailable

Special Considerations

• Pericardiocentesis may be harmful in AAA with cardiac tamponade as it reduces intrapericardial pressure and may cause recurrent bleeding 1

• Avoid delays in bleeding control for unstable patients - time to intervention directly correlates with mortality 1

• Beware of thrombosed AAA presenting with lower extremity ischemia rather than bleeding - requires prompt surgical intervention 6

• Crescent sign on CT (higher attenuation in thrombus) suggests bleeding into the intraluminal thrombus and is associated with rupture 7

Common Pitfalls

1. Delaying intervention for extensive diagnostic workup in unstable patients
2. Excessive fluid resuscitation causing increased bleeding from AAA
3. Failure to consider aortoenteric fistula in patients with history of AAA repair presenting with GI bleeding
4. Using vasodilators without beta-blockers in AAA patients, which can increase force of left ventricular ejection
5. Missing associated injuries in trauma patients with pelvic bleeding

Remember that AAA rupture has an extremely high mortality rate (80-90%), with most patients never reaching the hospital 2. Prompt recognition and immediate intervention are critical for survival.