Emergency Department Ultrasound at Auckland Hospital

1. Emergency Department Ultrasound at Auckland Hospital FAST and AAA: The first year

2. Objectives • The role of FAST • History of ED ultrasound at Auckland Hospital • The ultrasound credentialling process • How we performed in the first year • How we compare to the rest of the world • Where we go from here

3. FAST • Focused • Assessment • Sonography • Trauma

4. FAST • Integral part of initial trauma workup • Proven • Quick • Safe • Reliable • Reproducible • Repeatable

5. FAST • Pitfalls • Poor sonographer • Poor scan • Air • Obesity • Negative FAST doesn’t exclude injury! • Failure to serially examine the patient

6. History • 1998 Purchased portable ultrasound machine • 1998 First Australasian FAST course • 1999-2001 Sporadic use of ultrasound • Dec 2000 Formal Emergency Ultrasound credentialling program • Feb 2001 1st credentialled ED sonographers

7. The Credentialling Process - Background Radiologist Clinician Radiologist Clinician

8. The Credentialling Process - Background • Much debate in literature last 10 years • Consensus meeting • Each department decide own credentialling process • 200 scans and ongoing audit • Subsequent literature • Shackford 1999 4 yr experience • 50 scans • Suggests acceptable error rates

9. The Credentialling Process - Background • Workshop beneficial • Rozycki 1996 • Exit exam • Sisley 1999

10. The Credentialling Process - Background • American College of Emergency Physicians 2001 • 8 workshop hours • 25 scans in each of 6 areas • Can be partially credentialled • Only 1/76 departments met criteria • Boulanger 2000

11. The Credentialling Process - Background • Australasian College for Emergency Medicine • 16 workshop hours • 25 Accurate scans for FAST • 15 Accurate scans for AAA • >50% clinically indicated • Proctored by credentialled/ultrasound qualified person • Exit exam

12. Auckland ED • Adopted ACEM guideline December 2000 • 4 sonographers • Satisfied workshop requirement • Scans should not alter management • All measured against ‘gold standard’ • Proctored by radiologist • Standardised form • Monthly/bimonthly • Modified criteria for scans • 100% clinically indicated • Exit examination February 2001

13. Results FAST • 1 ED registrar ‘credentialled’ by June 2001 • 79% Indicated scans • 2/3 ED Specialists credentialled by Feb 2002 • All scans clinically indicated

14. Results FAST • For Detection Any Free Fluid • 113 scans in 102 patients over 13 months • 9 scanned by 2 sonographers • 1 scanned by 3 sonographers

15. TP 20 TN 83 FP 3 FN 7 Sn 74.1% Sp 96.5% PPV 87% NPV 92% Accuracy 91.2% Results FAST(Any Free Fluid) n=113

16. TP 11 TN 89 FP 5 FN 2 Sn 84.6% Sp 94.7% PPV 68.8% NPV 97.8% Accuracy 93.5% Results FAST(Laparotomy or Extra Investigation) n=107

17. Results FAST Existing literature • vs gold standard, novice sonographers • 3 studies • Sn 69-79% • Sp 96-98% • vs clinical observation and experienced sonographers • Sn 80-98% • Sp >90%

18. Errors FAST • 7 FN • 5/7 Trivial fluid, conservative management • 1 penetrating trauma with minor injury • 1 blunt trauma bladder injury, stable • All views adequate and correct interpretation according to radiologist

19. Errors FAST • 3 FP • 1 “ascites” • 1 “?pericardial effusion” • 1 Retroperitoneal and abdominal wall haematomas • Adequate views but incorrect interpretation

20. Result of errors FAST • 1 CT scan thorax for “?Pericardial effusion”

21. Emergency Department Ultrasound for AAA • 2 Case series in literature

22. Results AAA • 66 Scans in 58 Patients in 12 months • 5 Scanned by 2 sonographers • 1 Scanned by all 4 • 3/4 sufficient scans to meet requirement

23. TP 26 TN 39 FN 1 FP 0 Sn 96.3% SP 100% PPV 96.3% NPV 97.5% Accuracy 98.3% Results AAAn=66

24. “Error” AAA • Free air obscured 6cm AAA • Free fluid detected in Morison’s and Splenorenal recesses • Found to have perforated DU

25. Shuman 1998 n=60 Sn 97% Sp 100% Kuhn 2000 n=68 Sn 100% Sp 95% AAA Existing Literature

26. Time Taken to Scan • FAST median 5min (1-20) • AAA median 3.5 (1-16) • Similar to literature published

27. FAST Learning Curve • Debate about this • Shackford only author to look at initial experience • Suggests 10 scans before proficient • Showed ‘Institutional learning curve’ • 12 Individuals = wide variation in error rates • Only 4/12 had >25 scans in 4 years

28. FASTLearning Curve

29. FAST Learning Curve • Error rate <10% • Most ‘errors’ clinically insignificant • Individual variation

30. Potential Bias • Patients not consecutive • Opportunity for pre-selection of patients • Individual sonographers could discard unsatisfactory scans prior to proctoring

31. Summary • Emergency Department Ultrasound is established in Auckland Hospital • Accuracy mirrors existing literature • Pitfalls exist and should be considered

32. The future • Credentialling continues • Credentialled sonographers record in notes • Clinical management may alter • Ongoing audit • Expanded indications • Unstable patient with abdominal pain • Is there free fluid?

33. Case 1 • 37f • 4hr Abdominal pain • Collapse and seizure • Shock • Arrives ED 1755 • SLOH 1806

34. Case 1 • OT 1815

35. Case 2 • 28f • 1/2 hr Abdominal pain • HR 84, SBP 90, RR 16 • Arrives ED 0910 • S/B registrar 1000 • SLOH 1018

36. Case 2 • Urine pregnancy test 1025, positive

37. Case 2 • OT 1055

38. Case 3 • 19m • Fall from tree • Collapse at home • Fighting en route • Arrives ED 1635 • FAST 1645

39. Case 3 • OT for thoracotomy