1) The document discusses the use of echocardiography in evaluating patients in shock.
2) Basic echocardiography can readily identify the type of shock and guide diagnosis and management in most cases.
3) Key echocardiographic assessments include evaluating left ventricular size and function, identifying valvular pathology, assessing fluid status and volume responsiveness, and detecting causes of distributive, cardiogenic, obstructive, or hypovolemic shock.
4) Echocardiography is a useful first-line tool that can distinguish between different types of shock and serially monitor patients, helping clinicians optimize management of critically ill patients.
3. What is shock?
Types of Shock
Echocardiographic assessment of shocked patients
Take Home messages
Resources
Overview
?
What is the problem ?
4. Shock
A life‐ threatening, generalized form of circulatory failure
associated with inadequate oxygen delivery to the cells
Most cases of shock are mixed
“Septic and Cardiogenic”
“Hypovolemic and Dynamic LVOT obstruction”
The majority of shocked patients are readily identified using
basic echocardiography (Dx, Rx, Monitoring)
6. Cecconi M, De Backer A, Antonelli M, et al. Intensive Care Med. 2014;40:1795–815.
Evidence
Recommended as the modality of first choice in
consensus guidelines
10. Pearls
The LVOT velocity time integral (VTI) a surrogate for the stroke volume
Normal value >20 cm
Non-alignment of Doppler beam: VTI will be underestimated
Record the measured LVOT area in the file
Average of 5 measurements in AF
11. cardiac index
RV afterload
How does Mechanical Ventilation ↘ cardiac output?
12. Cautions
Ejection Fraction
Eyeballing is accurate with
experience
A prognostic marker in chronic
heart failure
effects of blood pressure (afterload), inotropes, and
vasopressors
HR, AF may
underestimate EF
13. Tissue Doppler Imaging
S’ Myocardial systolic velocity
Correlates with LVEF
Cautions
S’ with age
Doesn’t differntiate active contraction from tethering
Global Longitudinal Strain
identify systolic dysfunction in patients with normal LVEF in
oncology and heart failure patients
15. Diastolic Dysfunction
50% of patients with acute heart failure have preserved
ejection fraction
TDI analysis of the mitral annulus allows for rapid
estimation of left atrial pressure
16. E/A ratio >2 and E wave deceleration time <120 ms
predict a LAP >20 mmHg
Lateral e′ <10 and medial <7 cm/s are highly suggestive
of diastolic dysfunction and elevated left atrial
pressures
Average E/e′ of >14 elevated left atrial pressure
Pearl
E/e′ In Mechanically Ventilated patients 12
< spontaneous breathing patients
Diastolic Dysfunction
20. Hypovolemic Shock
Assessment of intravascular volume is the beginning in all types of shock
Hypovolemia is severe kissing walls
Fixed bowing of the atrial septum into the RA throughout the cardiac cycle
Elevated Left Atrial Pressure
Further Fluids not needed
1
2
Non-specific
24. Collapsibility Index
CI = (Dmax − Dmin )/Dmax ~ 100 %
DI = (Dmax − Dmin )/Dmin
In fully supported on Mechanical Ventilation
Distensibility Index
In the spontaneously breathing patient
26. Pitfalls
Not valid patients receiving partial ventilatory support
Only valid in the extremes
fluid responsiveness is determined if there is, on average, a >15 % increase
in SV or CO
32. Obstructive Shock
Resistance to blood flow through the cardiopulmonary Circulation
Causes:
acute pulmonary embolus
cardiac tamponade
type A dissection
tension pneumothorax
dynamic outflow obstruction
33. Dilated right chambers
decreased cardiac output
RV/LV area ratio >0.6;
gross dilatation is seen
with a ratio >1.0
Acute PE
changes in right ventricular contraction
elevated pulmonary artery pressures
intra‐ cavity emboli
Normal
Hyperdynamic
Hypodynamic
34. Acute PE
PAcT of 70– 90 ms indicates a pulmonary
artery systolic pressure of >70 mmHg
Mid‐systolic notch also indicates severe
pulmonary hypertension
D‐ shaped LV
35. Also in RV infarction
The McConnell’s sign
Non-specific
RV Free wall hypokinesia with preserved apex
36. When the intra-pericardial pressure exceeds right heart
filling pressure (diastole)
Cardiac Tamponade
Impaired filling of the chambers
Cardiac tamponade
Physiology
37. RA systolic collapse for longer than one-third of the
cardiac cycle
Cardiac Tamponade
RV diastolic collapse
Echo Findings
RA then RVOT then whole RV then LA then LV.
Dilated IVC
40. Size is not a guide to the presence of tamponade.
The opposite of respiratory variations if
positive pressure ventilation
Cardiac Tamponade
Pitfalls
Echo is the investigation of choice
Guides pericardiocentesis
41. Typical with basal septal hypertrophy
Dynamic LVOT Obstruction
close approximation of lateral wall and septum
Echo Findings
systolic anterior motion of the anterior mitral leaflet.
Dagger-shaped Doppler pattern of LVOT flow
42. Dynamic LVOT Obstruction
Causes Acute MI in the apical and mid segments
Stress Cardiomyopathy (Takatsubo)
Dobutamine in patients with small LV cavity (concentric LVH)
Hyperdynamic states (Sepsis, severe anemia)
Hypertrophic Cardiomyopathy
Sub-aortic membrane: fixed
Mitral valve surgery
43. Pitfalls
absence of septal hypertrophy in the elderly
Tachycardia, hypovolemia, and inotropes makes critically ill more prone to it
Dynamic LVOT Obstruction
45. Septic Shock
Heart is either the “Source” or the ”Victim” of the septic process
Left ventricular dilatation
LV, RV Systolic and Diastolic impairment
Valvular lesions (Functional, Endocarditis)
Ventricular outflow obstruction
Echo Findings
46. Early
Septic Shock
Small & Collapsing IVC
Small LV
LV and RV hyperkinesia
Small RV
A clue to the presence of marked peripheral vasodilatation.
49. Pitfalls
a normal study is not unusual
speckle tracking recently utilized to assess prognosis in such patients
Takutsubo Cardiomyopathy is reported
Septic Shock
Contractile dysfunction is reversible in sepsis over days, unless
concomitant CAD or myocarditis.
50. Chang, WT. et al. Intensive Care Med (2015) 41: 1791
LV GLS provides prognostic information as an outcome
predictor for mortality of septic shock patients.
111 ICU pts. with septic shock, over 2 yrs
51. Echo is the most single useful tool in the diagnosis and Rx of shock
Hyperdynamic LV also is highly specific for sepsis (94%).
Bedside Echo currently replaces mandatory CVP measurement in Sepsis
1
2
3
take-home messages5
LVOT VTI is a useful surrogate for LV Stroke Volume4
Dynamic serial assessment is the key to proper management.5
52. Resources
EACVI/ACCA recommendation for use of Echo in Acute Cardiac Care
Twitter: #POCUS #SMACC #FOAMEd #FOAMus #FOAMcc
ACCA Webinar (Critical Care Echo)
www.criticalecho.com
www.lifeinthefastlane.com
www.fate-protocol.com
McLean Critical Care (2016) 20:275