winfocus’ basic echo (wbe) hypovolemic shock and basic ...€¦ · tte normal values: 13 ± 2...

© WINFOCUS’ CRITICAL CARE ECHOCARDIOGRAPHY

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WINFOCUS’ BASIC ECHO (WBE)

Hypovolemic Shock and Basic Assessment of

Volume Status

Michael Lanspa, M.D.

Course Director, Critical Care Echocardiography Elective, Intermountain Medical Center

Clinical Instructor, University of Utah


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• FREQUENT CAUSE OF SHOCK

• VOLUME LOADING: OFTEN FIRST-LINE THERAPY TO IMPROVE HEMODYNAMIC STATUS (Dellinger RP. Crit Care Med 2013)

• ONLY 40-70% RESPONSE TO FLUID CHALLENGE (Michard F. Chest 2002)

• SIGNIFICANT DISADVANTAGES TO INAPPROPRIATE FLUID ADMINISTRATION (Wiedeman HP. NEJM 2006)

• ECHO: ADVANTAGES IN VOLUME STATUS ASSESSMENT (Charron C. Current Opin Crit Care 2006) !

Hypovolemia

Volume status manipula7on (volume loading and volume reduc7on with diuresis): one of the most frequent therapies in the management of our pa7ents !Specifically: describe the reasons for this topic to be relevant and should be part of an echo assessment, even in BASIC, FOCUSED ECHO


!Outline

1. Volume status

- Hypovolemia

- Volume overload

- Vasodilation

2. Volume responsiveness

3. Pitfalls


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A. Heart Chambers Dimension: LV End Diastolic Area (LVEDA)

End Systolic LV obliteration (Kissing Walls)

LVEDA < 5.5 cm/m2 (Body Surface Area)

Leung, et al. Anesthesiology 1994;81:1102-1109

SEVERE HYPOVOLEMIA

TTE normal values: 13 ± 2 cm2/m2 (10-18)

• Severe HYPOVOLEMIA is recognized by looking at the Dimension of the LV (not the RV because it has not a definite geometrical shape and its dimensions are more difficult to measure).

• A hypercontrac7le LV with very small ESA, or a small short axis LVEDA characterizes this situa7on. Here you see both 2-‐D and M-‐Mode clips of such a situa7on. On the leY you see “kissing” LV walls.


!EYEBALLING.....

The principle in evalua7ng a pa7ent is to recognize severe hypovolemia and underfilled LV. It is more of a pa^ern recogni7on, and with 7me and experience you will be able to recognize what is normal, like in the examples here on the top, as opposed to severe hypovolemia, as seen on the bo^om.


! Case 1 - Operating room

•51 y.o. F, EtOH abuse found at the bottom of flight of stairs

• GCS 3 at scene – intubated by EMS

• ED: 127/80, HR: 50

• CT: SDH/epidural hematoma

This is a case of a 51 y.o. with reported EtOH abuse, who was found at the bottom of a flight of stairs. GCS 3 at scene. Intubated in the field. In ED: stable VS, Total body CT. Head CT done showing large SDH



Patient was taken emergently to the OR for evacuation of SDH



•OR course: uneventful

• Surgeon starts to close incision – significant oozing from large scalp incision

•Patients goes into PEA arrests

•ACLS protocol initiated

OR course is uneventful until surgeon starts with closing incision, where significant amount of oozing is observed from incision. Then, the patient goes into PEA arrests and ACLS protocol is initiated. Once rhythm and BP returns focused TTE is done



Finally, a parasternal short axis view demonstrated same findings - severely underfilled LV with very small end-diastolic and end-systolic areas. The patient ended up expiring in the OR despite aggressive blood products resuscitation. The degree of hypovolemia was very severe. There were other injuries, like pelvic fracture, but the severe head injury was a priority.


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•“... right gluteal hematoma and blushes of contrast concerning for active extravasation into this hematoma...”

Case 1 - Operating room

In retrospect it was learned that she probably had ongoing bleeding from her pelvis injury...


!Small LVEDA = underloaded LV (not necessarily hypovolemia)

HYPOVOLEMIA SEVERE RV DYSFUNCTION

!

Remember that this means that the LV is underloaded, a condi7on not only found in hypovolemia, but also in severe RV dysfunc7on.

On the leY we see a parasternal short axis view of a pa7ent with hypovolemia and normal RV func7on.

This is in contrary to the clip on the right where we see the parasternal long axis view. Here the LV appears to be severely underfilled with “kissing ventricle” where the walls are clearly toughing each other indica7ng severe hypovolemia. Here, however, the RV is severely dysfunc7onal and the RV free wall is not moving inwards. In this case the e7ology of RV dysfunc7on was massive PE


!Small LVEDA = underloaded LV (not necessarily hypovolemia)

HYPOVOLEMIA SEVERE RV DYSFUNCTION

Always assess the RV… !

Remember that this means that the LV is underloaded, a condi7on not only found in hypovolemia, but also in severe RV dysfunc7on.

On the leY we see a parasternal short axis view of a pa7ent with hypovolemia and normal RV func7on.

This is in contrary to the clip on the right where we see the parasternal long axis view. Here the LV appears to be severely underfilled with “kissing ventricle” where the walls are clearly toughing each other indica7ng severe hypovolemia. Here, however, the RV is severely dysfunc7onal and the RV free wall is not moving inwards. In this case the e7ology of RV dysfunc7on was massive PE


!RV enlargement

Similar patient with pulmonary embolus. Note how the RV is enlarged, and it looks like the RV isn’t moving very well. If this were hypovolemia, one would expect that the RV should have normal function, and should be small


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*- Cheung, et al. Anesthesiology 1994;81:376-387 - Fissile et al, 2001;119:867-873

Decrease of 3 cm2 = 10% EBV loss *

LVEDA variation

• Clip on the right demonstrates increase LVEDA aYer fluid loading -‐-‐ visualiza7on of LV filling

• Clips shows LVEDA increase with volume loading.

•When LV is extremely underfilled (low absolute values of LVEDA) it is most of the 7me easy to diagnose hypovolemia.

•One way of doing this is give fluids, as seen on the graph on the leY. This graph demonstrates clips of different levels of LV filling; bo^om leY -‐ extremely underfilled where LV is on the steep part of the F-‐S curve, and with subsequent fluid loading one can see increased filling and size

• Apart from these extreme situa7on it is be^er to rely on flow varia:ons during volume loading, meaning that (at preserved contrac:lity) an actual capability to increase SV. This capability is lost on the flat part of the F-‐S curve. These concepts will be further explained in the advanced course


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FLUID CHALLENGE


LVEDA variation







!


FLUID CHALLENGE

FLUID CHALLENGE


LVEDA variation







!


FLUID CHALLENGE

FLUID CHALLENGE

FLUID CHALLENGE


LVEDA variation







!

TTE subcostal IVC View

C. STATIC IVC DIMENSION (end expiratory)

SPONTANEOUS BREATHING ONLY!

liver

liver

Hepatic Vein

RA

• Observa7on of IVC dimensions can be useful is specific situa7ons. Here, we are not talking here about its inspiratory varia7ons, but just about its sta7c values.

• First, go over subcostal view window (anatomy) in leY live 2D clip and cartoon on the right. When transi7oning, a s7ll image of the anatomy is seen on the right

• In the spontaneously breathing a well validated cutoff for severe hypovolemia is less than 1 cm

• For example, a study by Yanagawa et al demonstrated that in trauma, the diameter of the IVC was correlated with hypovolemia. In this study, the IVC diameter of pa7ents in shock was significantly smaller than those of control. A cut off of IVC diameter < 9 mm separated between the two groups in Trauma pa7ents

• In a different group by Lyons et al the authors interrogated the IVC diameter of people who donated blood (450 ml) and observed a sta7s7cally significant decrease in IVC diameter at the end of the procedure.

• One can see, though, how difficult it is for us as clinicians, when presented with an IVC diameter to discriminate between pa7ents with hypovolemia and those who are not.


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IVC end exp D ≤ 9 mmYanagawa et al. J Trauma 2005;58:825-829









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IVC end exp D ≤ 9 mmYanagawa et al. J Trauma 2005;58:825-829


IVC end exp D 17.4 mm → 11.9 mm

Lyon et al., Am J Em Med 2005;23:45-50








!Assessing RAP from IVC

IVC diameter Collapse with sniff RAP

< 2.1 >50% 0-5

5-10

>2.1 <50% >10

•Subcostal window •IVC in long axis, entering RA •2 cm before right atrium

Rudski et al. Guidelines for the Echocardiographic Assessment of the Right Heart in Adults. JASE 2010

Brennan et al in 2007 used calculated thresholds of 2.0cm and collapsibility of 40% for RAP >10. traditional classification of RAP into 5mmHg ranges was only 43% accurate


!Outline

1. Volume status

- Hypovolemia

- Volume overload

- Vasodilation


3. Pitfalls


!Volume Overload

DILATED, FIXED, IVC ( Systemic Venous Congestion )

TTE Apical 4 Chamber, Subcostal IVC

• These are very obvious situa:ons where volume does not need to be increased but it’s rather in excess: a fixed dilated IVC, is the common denominator of this situa7ons.

• Here are a few examples (press “enter” and go through three cases. Wait un7l each clip finishes before advancing to the next case)


!IVC plethora

Talk about how to recognize that the IVC is in plane the whole time.


!Assessing LAP from diastolic filling

This is a brief overview. You will be getting a detailed discussion of this in the next talk with Dr. Brown. Basically, diastolic function can be determined by the velocity of blood as it fills the ventricle, and the velocity at which the ventricle expands. The ratio of these two velocities worsens with increasing left atrial pressure.!This is basically the echocardiographer’s Pulmonary artery occlusion pressure (Wedge pressure)


!Assessing LAP from diastolic filling

Nagueh, JACC 1997; 30:1527-33

E/e’ <8 = Normal LAP E/e’ >15 = Elevated LAP


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Diastolic function LAPNormal 6-12Impaired relaxation 12-14Pseudonormal 15-22Restrictive >22

Diastolic function vs. LAP

SVC variation, Differentiate between CVP-IVC and from IVC-fluid responsiveness PA acceleration time to assess R-sided function. Include pictures of diastolic function. Clarify Diastolic function->LAP Hyperdynamic function V1 may be high


!Outline

1. Volume status

- Hypovolemia

- Volume overload

- Vasodilation


3. Pitfalls


!Vasodilation/Low SVRHYPOVOLEMIA

VASODILATION

• ….. peripheral arterial tone can be evaluated indirectly and roughly, but effec7vely.

• Both these Sep7c Shock pa7ents show in TG SAX view a hyperkine7c LV, with a small LV ESA. But first pa7ent also shows a reduced EDA, a sign of reduced preload, whereas second pa7ent with non-‐reduced EDA has a kissing ventricle not due to marked hypovolaemia but rather to reduced low peripheral arterial tone allowing for easier emptying of the LV….



VASODILATION

Low ESA

Low ESA





VASODILATION

Low EDA

Normal EDA

Low ESA

Low ESA




!Vasodilation/Low SVRHypotension

Diagnosis by Exclusion

• But the most useful informa7on comes from a deduc7ve reasoning. Up against a Hypotensive pa7ent with no significant RV dysf, no LV dysf and preload adequacy, the only possible explana7on for his hypotension is vasodila7on.



RV DILATION -‐ SYSTOLIC DYSFUNCTION ?







LV SYSTOLIC DYSFUNCTION?

NO





LOW PRELOAD

NO



NO




Vasodila2on !NO


LOW PRELOAD

NO



NO



!Outline

1. Volume status

- Hypovolemia

- Volume overload

- Vasodilation


3. Pitfalls


!Mechanical Ventilation

Lichtenstein D. Réanimation 1994

IVC EED

< 15 mm

‣ Poor correlation between need for volume loading & IVC static diameter ‣ Normal values in ventilated patients well-filled and adapted = 15-20 mm

• In posi:ve pressure ven:lated pa:ents, it is more difficult to interpret the sta:c IVC diameter.

• This is an example of a hypovolemic sep7c shock pa7ent, as demonstrated by this hyperkine7c, low EDA of the LeY Ventricle (with a non dysfunc7oning RV), in whom measured EE IVC is much greater than values considered as marker of severe hypovolemia in the spontaneously breathing. In Vent Pts there is in fact great variability. That’s why there’s no validated Sta7c IVC dimension as marker of severe hypovolemia. Empirically, a good cutoff value is smaller than 15mm


!Static measures are poor predictors of fluid response

• Collapse is better predictor of hemodynamic response to fluid than RAP or CVP

• SVC (from TEE) or IVC from (TTE)

Barbier, ICM 2004; 30:1740–1746

IVC collapsibility correlated with increase in cardiac index after a fluid challenge!Left is a scatterplot!Right is ROC curve, with good AUC!dIVC > 40% = hemodynamic response!


!IVC change to predict fluid response

Measurement Patient population

2004 Vieillard-Baron

∆SVC / SVC max 36% Mechanically ventilated, septic shock

2004 Barbier ∆IVC / IVC min 18% Mechanically ventilated, septic shock

2004 Feissel ∆IVC 12% Mechanically ventilated, septic shock

2011 Machare-Delgado

∆IVC 12% Mechanically ventilated, vasopressors

2012 Muller ∆IVC / IVC max 40% (positive) Spontaneously breathing, circulatory failure

2013 Lanspa ∆IVC / IVC max 15% (negative) Spontaneously breathing, septic shock

Multiple studies, with different patient populations


!Aortic Velocity Variation

• Correlates with hemodynamic response to fluid challenge

Feissel, Chest 2001; 119: 867-873

• Explain how to do this.

• Aortic velocity variation > 12% will likely lead to an increase in cardiac output > 15%

• Study performed in paralyzed, mechanically ventilated patients

• Talk about Regular rhythm, a fib, PVCs, asthma

• Skulec in 2009 demonstrated AoVV was predictive in spontaneously breathing volunteers who received lasix and IV fluids. 14% for peak velocity, 17% for VTI

• My own study didn’t reveal a strong signal in SB patients


!Outline

1. Volume status

- Hypovolemia

- Volume overload

- Vasodilation


3. Pitfalls


!

! LVEDA ≡ adequate preload ?

• If low values of LV EDA are a marker of severe hypovolemia, there is no reliable value for normo-‐volemia.

•As shown by this interes7ng study by Cheung et al, pa7ents submi^ed to graded hypovolemia (during heart surgery) show a linear reduc7on in LV EDA, and this correla7on is also true for pts with a dilated LV. But absolute EDA values aYer maximum blood withdrawal in pa7ents with abnormal LVs are s7ll above values of pa7ents with normal LV before withdrawal.

•Conclusion: Although LV EDA may help us recognize severe hypovolemia, “normal range” EDA cannot discriminate between hypovolemic and normo-‐volemic pa7ents


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Cheung, et al. Anesthesiology 1994;81:376-387






!

Cheung, et al. Anesthesiology 1994;81:376-387


No!





!54 Y.O. M, ACUTE PULMONARY EDEMA IN DILATED CARDIOMYOPATHY

Past History: Smoking, CAD, Triple CABG (3 y prior), Dilated Cardiomyopathy (EF 29%, LV EDV 180 ml) Recent History: Acute Dyspnea, Admitted to ED (SAP 230/120 mmHg, HR 130 (SR), PiO2/FiO2 100) Given diuretics, vasodilators, CPAP, then intubated, brought to ICU. Now: SAP 90/50, anuria, elevated lactic acid

And according to this I ask you: would you give fluids to this pa7ent with pulmonary edema?

Likely would respond. Likely would get worse pulmonary edema.

The answer is yes: cau7ously, but yes. He had Pulmonary edema not on the basis of volume overload, but rather due to the hypertensive crisis. He received diure7cs in the ER, and is now shocked due to hypovolemia, as this virtual IVC shows. He will probably not urinate without some fluids, and clearing those lungs will be very hard…. !So don’t rely exclusively on LV dimensions to judge adequacy of volume status (by the way, look at that RV how small it is ).


!Consider Respiratory effort

CPAP Helmet

62 Y.O. M – PNEUMONIA IN A PATIENT WITH COPD

IVC

!

• Another case to illustrate another poten7al pimall: according to respiratory varia7ons of this IVC in this CPAP helmet pa7ent is volume responsive, BUT….. He is not:

-Great varia7ons in this case are due to great respiratory efforts. He gets in fact intubated, and now ven7lated with the same PEEP he shows no more varia7ons (of course he is passive now, but there are no varia7ons in disten7on sugges7ve of responsiveness). !In these cases (spont or assisted ven:la:on) it’s important not to be mislead by varia7ons, but rather to rely on end exp diameter.


!Consider Respiratory effort

CPAP Helmet

Intubated, Paralyzed, PCV

62 Y.O. M – PNEUMONIA IN A PATIENT WITH COPD

IVC

!

• Another case to illustrate another poten7al pimall: according to respiratory varia7ons of this IVC in this CPAP helmet pa7ent is volume responsive, BUT….. He is not:

-Great varia7ons in this case are due to great respiratory efforts. He gets in fact intubated, and now ven7lated with the same PEEP he shows no more varia7ons (of course he is passive now, but there are no varia7ons in disten7on sugges7ve of responsiveness). !In these cases (spont or assisted ven:la:on) it’s important not to be mislead by varia7ons, but rather to rely on end exp diameter.


!

Cardiac Tamponade, Constrictive Pericarditis!

TTE 4-chamber viewTTE subcostal view

IVC dilatation and plethora does not always mean no need for fluids

• Finally, there are cases such as Cardiac Tamponade, or Constric7ve Pericardi7s, where systemic venous conges:on is not due to volume overload, but rather to RV extrinsic compression / restric:on.

• This is an example of cardiac tamponade in a pa7ent with a para-‐neoplas7c syndrome.


!Take Home Messages

BASIC VOLUME STATUS ASSESSMENT


!Take Home Messages

BASIC VOLUME STATUS ASSESSMENT• EASY IN SEVERE HYPOVOLEMIA, HYPERVOLEMIA


!Take Home Messages


• LESS SEVERE HYPOVOLEMIA / SIGNIFICANT CARDIAC DISEASE: ADVANCED ECHO (VOLUME RESPONSIVENESS, FILLING PRESSURES)


!Take Home Messages


• LESS SEVERE HYPOVOLEMIA / SIGNIFICANT CARDIAC DISEASE: ADVANCED ECHO (VOLUME RESPONSIVENESS, FILLING PRESSURES)

• VOLUME STATUS ≠ VOLUME RESPONSIVENESS

winfocus’ basic echo (wbe) hypovolemic shock and basic ...€¦ · tte normal values: 13 ± 2...

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