Download - 11 shock algorithm
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The shocked patient
Adapted from Lichtenstein's BLUE points & FALLS protocol
(with permission)
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Summary
1 (Ongoing resus) Clinical assessment: formulate the question
2 Rapid shock screen3 Form a working diagnosis4 Continue resuscitation 5 Re-scan / monitor progress / further
investigations
1. Formulate the question
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1. Formulate the question
a. Should I give more fluids? (Or inotropes, or vasopressors?)
b. Why is the patient shocked?
The shock screen won’t tell you the diagnosis every time, but it will tell you when not to give IV fluids… or when to stop (B profile
appears)
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Why is the patient shocked?
• Obstructive (TPTX, massive PE, tamponade)
• Cardiogenic• Hypovolaemic (fluid loss, 3rd spacing…)• Distributive (septic, anaphylactic,
neurogenic)• Dissociative (CO, cyanide)
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Why is the patient shocked?
• Obstructive (TPTX, massive PE, tamponade)
• Cardiogenic (lung rockets)• Hypovolaemic (fluid loss, 3rd spacing…)• Distributive (septic, anaphylactic,
neurogenic)• Dissociative (CO, cyanide)
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Should I give more fluids?
• Lungs: wet or dry?• IVC: collapsing or distended?
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Should I give more fluids?
Wet lungsDistended IVC… probably not
(NB look for ‘APO mimics’ eg fibrosis, and ‘fluid overload mimics’
eg cor pulmonale)
Dry lungsSmall IVC
…yes (but re-scan with every bag of IV fluid: if still shocked & B profile appears, cease fluids)
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What if lungs dry & large IVC?(or lungs wet & small IVC?)
A. Each sign has false positives & negatives.
Go back & reassess the patient, then synthesize your findings.
=Be a doctor.
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What about large LA/LV?Surely that suggests I should avoid IVT?
A. Not in isolation.Even patients with dilated cardiomyopathy
can suffer hypovolaemic shock.
But be sensible & consider smaller boluses, and correlate with other findings.
2. The shock screen
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Curved probe, abdominal preset
• Machine settings: as for arrest screen
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A 3-step scan (plus 1)
1. Anterior lung fields (this time 2 points)2. Single view heart3. IVC (hypovolaemia / obstructive shock)4. Take a step back & consider:
• Leg veins (obstructive: PE)• Abdo (hypovol: AAA / free fluid)• Other tests
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The shock scan
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The shock scan
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Step 1: anterior chest: upper & lower BLUE points
• Probe sagittal, midclavicular line• 2 spots on each side• i.e. upper chest & lower chest
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Recall: upper & lower BLUE points
1 1
2 2
Step 1 findings
One lung not sliding
Both lungs slidng
A’ profile B’ profile A profile B profile A/B or C profile
Recall: A lines versus B lines
A lines B lines
Recall: A lines versus B lines
A linesHorizontal artefactsOnly air is presentPresent in dry lungsPresent in PTX
B linesVertical artefactsAir/fluid mix in lungNot seen in PTXEven 1 B line rules
out PTX at that site
A vs A’ profile: is sliding present?
A vs A’ profile: is sliding present?
A vs A’ profile: is sliding present?
A or A’ profile?
A or A’ profile?
A & A’ profile
A lines (or no lines) in all 4 lung windows+
Pleural sliding present = A profile = dry lungsPleural sliding absent = A’ profile = PTX /
1 lung ventilation / other
B & B’ profile:Multiple B lines = wet lungs
Multiple B lines = pulmonary oedemaAPO = cardiogenic oedema
ARDS = non cardiogenic oedemaPneumonia = local oedema
Note the difference w.r.t. pleural sliding
ARDS/ disseminated pneumonia:Exudate
Proteinaceous‘sticky’
Reduced / absent lung sliding, irregular
pleural lineB’ profile
APO:Transudate
Lung sliding is preserved, smooth
pleural lineB profile
B or B’ profile?
B or B’ profile?
B or B’ profile?
B & B’ profile
At least 3 B lines in all 4 anterior windows= wet lungs
Pleural sliding present = B profile = APO
Pleural sliding reduced /absent, irregular pleural line = B’ profile = disseminated pneumonia / ARDS
Is that 100% true?
No, but it’s close.B profile + preserved lung sliding = almost
always APO.B profile + absent sliding = almost always
pneumonia.
NB remember the 90% rule
Recall: A/B profile
The windows show a mix of A & B=
Patchy wet lung(s) (usu pneumonia)
Recall: C profile
Recall: C profile
The windows show anterior consolidation=
PneumoniaARDS
(rarely: PE)
Small amounts of consolidation = ‘irregular pleural line’
Step 1 findings
One lung not sliding
Both lungs sliding
A’ profile B’ profile A profile B profile A/B or C profile
Step 1 findings
One lung not sliding
Both lungs sliding
A profile:Continue
IVT
B profile:Pulmonary
OedemaTreat.
A/B or C profile:
PneumoniaContinue
IVTTreat cause.
A’ profile:PTX?
Look for lung point,consider DDX. Treat
B’ profile:Pneumonia
Treat.
Step 2
Step 2 (after PTX ruled out)
Single view of heart
Wait a minute!
Do I need to scan the heart if I already have a diagnosis from the lung scan (PTX,
pneumonia, APO)?
Controversial
Most of us would still scan heart to be sure.Some wouldn’t.
(See APO note next slide)
This step only yields useful information if it demonstrates obvious pathology: ie ‘rule in, not rule out’.
If negative, you will need to proceed to step 3.
Step 2 (if lung sliding & B profile)
This is usually acute cardiogenic pulmonary oedema (APO). Occasionally severe bilateral
pneumonia / ARDS can look like this.
Fibrosis can look like this, but is usually limited to upper or lower lobes.
If you saw B profile on step 1…… and step 2 shows poor
LV function= acute cardiogenic
pulmonary oedema(APO)
And step 2 shows ‘normal’ LVStill probably APO- start
treating(but re-check clinical picture
to be sure it's not severe bilateral pneumonia /
ARDS)
LV failure commonly appears as spuriously 'normal' LV on basic 2D echo. So if B profile but heart looks OK, start
treating for APO, then proceed to focused TTE & reassess patient.
Back to the heart.What am I looking for?
Tamponade?Massive PE?
Hypovolaemia?
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Step 2: single view heart
• Using the curved probe, subcostal view is easiest• Probe transverse, marker to patient's right• ID heart (probe angled cephalad)• Options if you can't obtain an adequate view:
• Try different window (apical, parasternal)• Try different probe (phased array)• Get help
Subcostal scan heart
Step 2: single view heart (& dry lungs)
Big RVSquashing LV
Pericardial fluid Inadequate view
Small volume heart
Heart grossly NAD
?
Step 2: single view heart (& dry lungs)
Big RVSquashing LV
Pericardial fluid
Inadequate view
Small chambers or heart grossly
normal
PE (probably)
Consider
thrombolysis
Tamponade (probably)
Drainage
Hypovolaemia/ sepsis?Could still be PE!
IV fluidProceed to step 3
Try another windowTry cardiac probe
Get help
Step 3
IVC
Hang on!
Do I need to scan the IVC if I already have a diagnosis from steps 1 & 2?
(PTX, massive PE, tamponade, pneumonia, APO)
Controversial
Not if Dx already obvious (eg tamponade).Yes if Dx still unclear: dry lungs, small volume
heart (e.g. you haven’t ruled out PE yet)But remember that IVC can be ‘falsely’ large
(eg cor pulmonale) and ‘falsely’ small (eg XS probe pressure)
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So proceed to step 3...
...if lungs are dry & no obvious PE or tamponade
But be a doctor & synthesize the findings.
Step 3: dry lungs, small vol heart, IVC
Anything elseSmall IVC
Large IVC & collapsing
Inadequate view
Large IVC<50% collapse
?
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IVC 1
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IVC 1
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IVC 2
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IVC 3 (transverse)
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IVC 3 (transverse)
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Large IVC (>2.3cm), <50% collapse
= elevated CVPMultiple causes
…but probably not fluid responsive
Actions:Reassess clinical picture
Consider other testsAvoid indiscriminate IVT
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Anything else
Small IVC <1.5cmCollapsing IVC >50%
= fluid responsive
Actions:Give IVT
Proceed to step 4
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Inadequate view
Reconsider whether you really need the IVC information
Actions:Either get help
Or proceed to step 4
So: dry lungs, small vol heart, IVC…
Anything elseSmall IVC, not collapsing
Large IVC, collapsing
Inadequate view
Large IVC<50% collapse
Caution with fluidsProceed to step 4
Give fluidsProceed to step 4
Get help or cut your losses
Proceed to step 4
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Step 4
• Take a step back• Have a think (& another look at the patient &
other information)• What causes have I excluded?• What else is left?• Can bedside US help any further?
• Abdomen (hypovol: AAA / free fluid)• Leg veins (obstructive: PE)
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Who needs step 4?
Anyone with:Dry lungs, lung sliding present, diagnosis still
unclear, and…***shock unresponsive to fluids***
Is it sepsis?Is it a ruptured AAA?
Is it PE?
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Step 4
Options: either/ both of:3-point compression DVT scan (is it a PE?)
Abdomen (is it AAA? Free fluid?)
Step 4: dry lungs, diagnosis unclear, shock unresponsive to IV fluids
DVT not seen:Scan the abdomen
DVT seen= PE
3-point compression leg veins
Normal aortaAAA ruled out
Now what?PTO
AAA seen =Ruptured AAA
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Now what?
You’ve reached the end of the scanPatient still shockedFluids didn’t work
You’ve ruled out cardiogenic, PTX, tamponade
…but not PE.If it’s still on your list, you need a different
test.
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But while arranging other tests…
Keep scanning the lungs
If lungs still dry, you can give more IV fluid
Once B profile appears or patient improves, cease fluids
Recap: the shock scan
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A 3-step scan (plus 1)
1. Anterior lung fields (this time 2 points)2. Single view heart3. IVC (hypovolaemia / obstructive shock)4. Take a step back & consider:
• Leg veins (obstructive: PE)• Abdo (hypovol: AAA / free fluid)• Other tests
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The shock scan
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The shock scan
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Further tests?
After resuscitation phaseIf shock screen didn't sufficeIf clinical picture demands it
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Summary
The shock screen won’t tell you the diagnosis every time, but it will tell you when it’s safe to give IV fluids (dry lungs & small IVC)… or when to stop (wet lungs, large
IVC).