What is the target systolic blood pressure to achieve in a suspected leaking abdominal aortic aneurysm (AAA)?

Target Systolic Blood Pressure in Suspected Leaking Abdominal Aortic Aneurysm

In suspected leaking abdominal aortic aneurysm (AAA), the target systolic blood pressure should be 80-90 mmHg until major bleeding has been stopped.

Rationale for Permissive Hypotension

The European guidelines on management of major bleeding and coagulopathy following trauma strongly recommend a restricted volume replacement strategy with permissive hypotension in cases of suspected leaking AAA 1. This approach aims to:

• Prevent dislodgement of blood clots
• Avoid dilution of coagulation factors
• Prevent increased hydrostatic pressure on the bleeding site
• Minimize further bleeding from the aneurysm

The concept of permissive hypotension (also called "controlled hypotensive fluid resuscitation") maintains a level of tissue perfusion that, although lower than normal, is adequate for short periods while avoiding the adverse effects of aggressive fluid resuscitation 1.

Specific Blood Pressure Targets

The specific recommendations for blood pressure management in suspected leaking AAA are:

• Target systolic BP: 80-90 mmHg until major bleeding has been controlled 1
• This target applies specifically to patients without traumatic brain injury
• If the patient has concomitant traumatic brain injury, a higher mean arterial pressure of ≥80 mmHg should be maintained 1

Implementation Strategy

1. Initial assessment: Rapidly identify signs of shock and visible bleeding

2. Vascular access: Establish large-bore IV access

3. Fluid management:

   • Begin with restricted crystalloid therapy
   • Use 0.9% sodium chloride or balanced crystalloid solution 1
   • Avoid aggressive fluid resuscitation that normalizes blood pressure before bleeding control 2

4. Blood pressure monitoring:

   • Use invasive arterial line monitoring when possible 1
   • Continuous ECG recording is recommended 1

5. If target BP cannot be achieved with fluid restriction alone:

   • Add noradrenaline (norepinephrine) to maintain the target arterial pressure 1
   • Consider dobutamine if myocardial dysfunction is present 1

Important Caveats and Considerations

• This permissive hypotension strategy should only be used until definitive control of bleeding is achieved
• Prolonged hypotension can lead to organ damage and should be avoided
• In patients with pre-existing hypertension, the target may need slight adjustment (but still maintaining the principle of permissive hypotension)
• Elderly patients may have less physiological reserve to tolerate hypotension
• The role of permissive hypotension in patients with concomitant traumatic brain injury should be considered only in exceptional circumstances 1

Monitoring During Resuscitation

• Continuous arterial blood pressure monitoring
• Heart rate and ECG monitoring
• Serum lactate and base deficit to assess tissue perfusion 1
• Urine output
• Mental status (if patient is conscious)

This permissive hypotension approach (SBP 80-90 mmHg) represents the current standard of care for suspected leaking AAA based on the most recent European guidelines, with the goal of reducing morbidity and mortality by preventing further bleeding while maintaining adequate organ perfusion until definitive surgical or endovascular intervention can be performed.