ultrasound in undifferentiated shock
TRANSCRIPT
Ultrasound in Undifferentiated Shock
Dr James Wheeler BSC (Hons) MBBS FACEM DDU (General)
Emergency Physician SCGH
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
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
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
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!
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
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)
Shock – CausesCause ExampleHypovolaemia Haemorrhage (trauma, AAA, ectopic)
GI Loss (gastroenteritis)Renal Loss (DKA)Reduced intake
Cardiogenic AMICardiomyopathyValvular failureVentricular aneurysm / rupture
Obstructive Tension PTXTamponadeMassive PEHCMAtrial myxoma
Distributive SepsisAnaphylaxisNeurogenicToxicological
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
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 therapyPOCUS 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 0.283Days in ICU 4.41 6.67 0.2
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
US Protocols for Shock Assessment:The image part with relationship ID rId2 was not found in the file.
Rapid Ultrasound in Shock (RUSH)
Rapid Ultrasound in Shock (RUSH)The image part with relationship ID rId2 was not found in the file.
BestViews
Rapid Ultrasound in Shock (RUSH)The image part with relationship ID rId2 was not found in the file.
Rapid Ultrasound in Shock (RUSH)The image part with relationship ID rId2 was not found in the file.
Hypovalaemia Shock
• Haemorrhage – Ruptured AAA / Ectopic Pregnancy / Solid organ injury / Thoracic injury• GI Loss – Gastroenteritis• Renal loss – DKA• Reduced Intake
Hypovolaemia - IVC Collapse / Variability
Hypovolaemia - IVC Collapse / Variability
Hypovalemia - IP Free Fluid / Haemorrhage
Hypovalemia - IP Free Fluid / Haemorrhage
Hypovolaemia – Ruptured Ectopic Pregnancy
Hypovolaemia – AAA (?signs of rupture)
Hypovolaemia – AAA (?signs of rupture)
Aortic Dissection
Aortic Dissection
Cardiogenic Shock
• AMI• Acute valvular dysfunction• Ventricular aneurysm• Cardiac rupture• Cardiomyopathy (acute or chronic)
Cardiogenic – LV Contractility
Cardiogenic – LV Contractility
Cardiogenic - AMI – RWM AbN
Cardiogenic - AMI – RWM AbN
Cardiogenic – Pulmonary Oedema
Cardiogenic - APO & Pleural Effusions
Cardiogenic - APO & Pleural Effusions
Obstructive Shock
• Massive or Sub-Massive PE• Cardiac Tamponade• Tension PTX
Obstructive – PE
Obstructive – PE - RV Dilatation
Obstructive – PE - RV Dilatation
Obstructive – PE - RV Dilatation / Contractility
Obstructive – PE - RV Dilatation / Contractility
Obstructive – PE / Tamponade:IVC Fixed Distension
DVT
Obstructive – Pericardial Tamponade (Subcostal)
Obstructive – Pericardial Tamponade (PLX)
Obstructive – Pericardial Effusion (PLX)
Obstructive – ??Pericardial Effusion
Obstructive - ?Tension Pneumothorax
Lung Contact Point
Thoracic Aortic Aneurysm with Tamponade
Distributive Shock
• Sepsis (?source)• Anaphylaxis• High Spinal Injury• Toxicological Vasoplegia
Distributive – Intraperitoneal Gas & Fluid
Distributive – ?Sepsis Source
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