Ultrasound in undifferentiated shock

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