FAST Exam Protocol — Focused Assessment with Sonography in Trauma
Structured 4-window ultrasound assessment to detect free fluid (haemoperitoneum, haemopericardium) in trauma. Extended FAST (eFAST) adds bilateral pleural windows.
Score interpretation
FAST negative in stable patient: Low probability of significant intra-abdominal injury.
→ Serial clinical examination. Repeat FAST at 30 min if mechanism high-risk. Consider CT abdomen/pelvis if clinical suspicion persists despite negative FAST. Observation for minimum 6 hours. FAST has sensitivity ~85% — negative does not exclude injury.
FAST positive in haemodynamically stable patient. Free fluid confirmed.
→ CT trauma scan (pan-scan): chest/abdomen/pelvis with IV contrast if haemodynamically stable. Trauma surgery review. Volume resuscitation. Permissive hypotension if surgical control imminent. Prioritise ATLS management. Repeat FAST if status changes.
FAST positive in haemodynamically unstable patient OR cardiac tamponade. Immediate operative intervention.
→ IMMEDIATE surgical intervention — do NOT delay for CT. Haemoperitoneum + unstable: emergency laparotomy. Cardiac tamponade: pericardiocentesis or emergency thoracotomy. Tension pneumothorax: needle decompression + chest drain. Call trauma team / senior surgeon STAT. Activate massive transfusion protocol.
Interpretation bands for the FAST Exam. Apply clinical judgement and local guidance.
References
- ATLS Student Course Manual, 10th Edition. American College of Surgeons. 2018.
- Rozycki GS et al. The role of surgeon-performed ultrasound in patients with possible cardiac wounds. Ann Surg. 1996.
Related
Curated clinical cross-links plus same-class fallbacks.
- Neostigmine · Anticholinesterase (Reversal Agent)
- Prilocaine · Local Anaesthetic (Amide)
- Tranexamic Acid (ICU/Trauma/Surgical) · Antifibrinolytic
- Mepivacaine with adrenaline · Amide LA + vasoconstrictor
- Neostigmine with glycopyrronium · Anticholinesterase + antimuscarinic
- Lidocaine hydrochloride · Amide local anaesthetic / Class IB antiarrhythmic
- Difficult Airway Algorithm (DAS) · DAS 2015; Royal College of Anaesthetists
- Major Haemorrhage Protocol · NICE NG24; UK MHP guidelines
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.