Immediate Management of a Patient with Positive FAST Result
For patients with a positive FAST examination and hemodynamic instability, immediate surgical intervention is required, as mortality increases approximately 1% every 3 minutes if surgical intervention is delayed. 1
Management Algorithm Based on Hemodynamic Status
Hemodynamically Unstable Patients
- Proceed directly to the operating room for immediate exploratory laparotomy without further diagnostic testing, as ultrasound examination has sensitivity and specificity close to 100% when patients are hypotensive 1
- Apply damage control surgery principles with rapid control of hemorrhage as the primary goal 1
- Do not delay surgical intervention for additional imaging studies, as each 3-minute delay increases mortality by approximately 1% 1
- Be aware that a positive FAST has an extremely high positive likelihood ratio (34.3) for adverse outcomes requiring intervention 2
Hemodynamically Stable Patients
- Proceed to CT scan for further evaluation of specific organ injuries to guide potential non-operative management 1
- CT provides superior information about specific organ injuries compared to FAST examination alone 1
- In centers with integrated emergency room CT scanners, whole-body scanning can be completed in under 30 seconds, allowing rapid diagnosis 1
- Continue close monitoring for any signs of hemodynamic deterioration, as some injuries may be missed by initial FAST examination 3
Clinical Considerations and Pitfalls
- Be aware that FAST has high specificity (96-99%) but moderate sensitivity (74-77%) for detecting intra-abdominal free fluid 1
- False positives can occur, particularly in patients who have received massive fluid resuscitation prior to FAST examination, as transudative intraperitoneal fluid can mimic hemoperitoneum 4
- FAST examination should focus on four key areas: pericardium, right upper abdominal quadrant, left upper abdominal quadrant, and pelvis 5
- Consider extended FAST (e-FAST) to evaluate for hemothorax and pneumothorax, especially in patients with thoracoabdominal injuries 5
- Remember that FAST is designed to provide a simple "yes or no" answer regarding the presence of bleeding, not to quantify bleeding or evaluate specific organ lesions 5
- Hand-held FAST devices can be valuable in resource-limited settings but may miss approximately 3% of injuries requiring intervention 3
Integration with Clinical Decision-Making
- FAST facilitates appropriate decisions in the resuscitation area in 99% of cases 1
- For penetrating trauma of the thoracoabdominal transition, FAST can help determine if the abdominal cavity has been penetrated 5
- In cases where the cause of hemodynamic instability is unknown, FAST can provide valuable diagnostic information 5
- The FAST exam provides valuable prognostic information at minimal expense during early resuscitation 2