This document discusses using point-of-care ultrasound to investigate the cause of undifferentiated shock in emergency department patients. It describes various ultrasound protocols that can be used to examine the heart, lungs, abdomen, and veins to identify causes of shock like hypovolaemia, cardiogenic shock, pulmonary embolism, tamponade, and sepsis. Studies have found ultrasound can reduce the time to diagnosis in shock, decrease the use of vasopressors, and lead to fewer ICU days and lower morbidity compared to clinical examination alone. The limitations of ultrasound include operator dependence and difficulty obtaining views in critically ill patients.

1. Ultrasound in Undifferentiated
Shock
Dr James Wheeler BSC (Hons) MBBS FACEM DDU (General)
Emergency Physician SCGH

2. What we will cover
• What is point of care ultrasound
– SCGH ED US Service
• Shock
– Definitions / Causes / Treatments
• How US may be used to investigate a patient with undifferentiated shock
– Some ultrasound protocols
– Limitations of US examination
– Some examples of sonographic findings in particular causes of shock
• What we won’t cover:
– How to perform an ultrasound
– Detailed interpretation of ultrasound

3. Point of Care / Bedside Ultrasound
• Use of US at the patients bedside to answer
specific clinical questions and assist in
clinical diagnosis and management
– Also help guide certain procedural treatments
(IV access, pericardiocentesis etc…)
• Advantages:
– Bedside (no transfer out of dept.)
– Can be accessed immediately
– Nil radiation
– Functional imaging (CO, PAP...)
– Assessment can be adapted to fit clinical
assessment & sonographic findings
• Limitations:
– Training / experience and operator dependent
– Sometimes difficult to obtain certain views
(sonographic windows) in critically unwell /
unprepared patients

4. SCGH ED US Service
• Established 2005
• Internationally regarded (thanks to Ass Prof James Rippey)
• 6 DDU FACEM’s (General and Emergency), 1 Fellow, 1 Registrar
– DDU = 2 years supervised US training, primary and secondary exams
– One consultant rostered for EDUS 0800-1800 weekdays (afterhours as per our
rostering)
• Skills of US examination are now becoming an essential part of critical care
training
– Other members of the ED, and other critical care, staff have varying levels of
training and experience in critical care and procedural ultrasound

5. SCGH ED Service: What do we do?
Diagnostic Procedural Critical Care
• Abdominal
• Reproductive systems
• Vascular (some)
• Musculo-skeletal (some)
• Cardiac
• Lung
• Ocular
• Masses
• Vascular access (PVC,
CVC, arterial)
• Effusion drainage (joint,
pleural, pericardial,
ascitic)
• Abscess drainage
• Nerve blocks
• Foreign body removal
• Cardiac arrest
• Major trauma (EFAST)
• Chest pain
• Collapse
• Shortness of breath
• Sepsis (?source ?fluids
or inotropes)
• Pregnancy related
abdominal pain
• Undifferentiated shock
…and Education / Teaching!

6. Shock
• Hypotension Defn:
– SBP < 90mmHg
– Shock Index (HR/SBP) probably better indicator of potential shock (N 0.5-0.8, SI > 1 ?Shock)
• Shock Defn:
– Life–threatening condition of circulatory failure resulting in inadequate tissue
perfusion, cellular hypoxia and END ORGAN DYSFUNCTION (confusion, renal
failure, hepatic failure….)
• Undifferentiated Shock:
– Shock is recognised, but the cause is unclear

7. Undifferentiated shock
• Relatively common in ED
• Important predictor of mortality
• Different subtypes of shock require different management (that may be life-
saving if done in a timely fashion)

8. Shock – Causes
Cause Example
Hypovolaemia Haemorrhage (trauma, AAA, ectopic)
GI Loss (gastroenteritis)
Renal Loss (DKA)
Reduced intake
Cardiogenic AMI
Cardiomyopathy
Valvular failure
Ventricular aneurysm / rupture
Obstructive Tension PTX
Tamponade
Massive PE
HCM
Atrial myxoma
Distributive Sepsis
Anaphylaxis
Neurogenic
Toxicological

9. Evidence – US in Shock
• Overall very good agreement (90 – 100%) between the US diagnosis (~20mins post
arrival) and final diagnosis (k = 0.71 – 0.9) 1, 2, 3
• Changes in Mx:
– Decreases physician diagnostic uncertainty
– Increased patients with transferred from ED with a definitive diagnosis
– 24.6% of patients had a significant change in the use of IV fluids, vasoactive agents, or
blood products. 2
– Major diagnostic imaging (30.5%), consultation (13.6%), and emergency department
disposition (11.9%) 2

10. Patients evaluated with POCUS had less time on vasopressors and
showed trends toward fewer days in the ICU and decreased morbidity
• Unpublished
• April 2016
• 45 patients (22 had US, 23 did not) in ICU
(Portland USA)
• Assessed fluid responsiveness (resp change in
IVC diameter, LVOT VTI after SLR)
• Results:
– 38% reduction in time on vasopressor (p = 0.038)
– Trends to reduction in hours on ventilators and
days in ICU (see next slide)
– Calculated savings of ~$20,000 / patient
Impact of POCUS on therapy
POCUS
group
Control
group
p-value
Total hours
on
vasopressors
36.43 58.57 0.038
Hours to 50%
wean off
vasopressors
22.24 40.66 0.0952
Total hours
on ventilator
68.3 133.67 0.283
Days in ICU 4.41 6.67 0.2

11. US in Undifferentiated Shock
• Many different target-directed US exams developed to determine cause/s of
shock
• At SCGH ED often tailored / focused US examination to answer clinical
questions relevant to the clinical assessment of the patient
• Note: US also useful in guiding treatment procedures and monitoring
response to treatment in this patient group

12. US Protocols for Shock Assessment:
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14. Rapid Ultrasound in Shock (RUSH)

15. Rapid Ultrasound in Shock (RUSH)
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16. Best
Views

17. Rapid Ultrasound in Shock (RUSH)
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18. Rapid Ultrasound in Shock (RUSH)
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19. Hypovalaemia Shock
• Haemorrhage – Ruptured AAA / Ectopic Pregnancy / Solid organ injury / Thoracic injury
• GI Loss – Gastroenteritis
• Renal loss – DKA
• Reduced Intake

20. Hypovolaemia - IVC Collapse / Variability

21. Hypovolaemia - IVC Collapse / Variability

22. Hypovalemia - IP Free Fluid / Haemorrhage

23. Hypovalemia - IP Free Fluid / Haemorrhage

24. Hypovolaemia – Ruptured Ectopic Pregnancy

25. Hypovolaemia – AAA (?signs of rupture)

26. Hypovolaemia – AAA (?signs of rupture)

27. Aortic Dissection

28. Aortic Dissection

29. Cardiogenic Shock
• AMI
• Acute valvular dysfunction
• Ventricular aneurysm
• Cardiac rupture
• Cardiomyopathy (acute or chronic)

30. Cardiogenic – LV Contractility

31. Cardiogenic – LV Contractility

32. Cardiogenic - AMI – RWM AbN

33. Cardiogenic - AMI – RWM AbN

34. Cardiogenic – Pulmonary Oedema

35. Cardiogenic - APO & Pleural Effusions

36. Cardiogenic - APO & Pleural Effusions

37. Obstructive Shock
• Massive or Sub-Massive PE
• Cardiac Tamponade
• Tension PTX

38. Obstructive – PE

39. Obstructive – PE - RV Dilatation

40. Obstructive – PE - RV Dilatation

41. Obstructive – PE - RV Dilatation / Contractility

42. Obstructive – PE - RV Dilatation / Contractility

43. Obstructive – PE / Tamponade:
IVC Fixed Distension

44. DVT

45. Obstructive – Pericardial Tamponade (Subcostal)

46. Obstructive – Pericardial Tamponade (PLX)

47. Obstructive – Pericardial Effusion (PLX)

48. Obstructive – ??Pericardial Effusion

49. Obstructive - ?Tension Pneumothorax

50. Lung Contact Point

51. Thoracic Aortic Aneurysm with Tamponade

52. Distributive Shock
• Sepsis (?source)
• Anaphylaxis
• High Spinal Injury
• Toxicological Vasoplegia

53. Distributive – Intraperitoneal Gas & Fluid

54. Distributive – ?Sepsis Source

55. References:
1. Ghane et al. Accuracy of Rapid Ultrasound in Shock (RUSH) Exam for
Diagnosis of Shock in Critically Ill Patients. J Emerg Trauma Shock. 2015
Jan-Mar;8(1):5-10.
2. Shokoohi et al. Bedside Ultrasound Reduces Diagnostic Uncertainty and
Guides Resuscitation in Patients With Undifferentiated Hypotension. Crit
Care Med. 2015 Dec;43(12):2562-9
3. Volpicelli et al. Point-of-care multiorgan ultrasonography for the
evaluation of undifferentiated hypotension in the emergency department.
Intensive Care Med (2013) 39:1290–1298