inferior vena cava guided fluid resuscitation

©2015 MFMER | slide-1

Inferior Vena Cava Guided Fluid ResuscitationPro – Con Debate

William ‘Brian’ Beam – Hon Liang Tan

Critical Care Grand Round26 Feb 2015


Have responded with nothing to disclose.

William (Brian) Beam, MD

Hon Liang Tan, MBBS

Critical Care Grand Rounds

Disclosure Summary


Planning committee members who have nothing to disclose:

Richard A. Oeckler, MD, PhD, Co-Director

Juan N. Pulido, MD, Co-Director

Kim Jones, Program Coordinator

Disclosure Summary

As a provider accredited by ACCME, Mayo Clinic College of Medicine (Mayo School of CPD) must ensure balance, independence,

objectivity and scientific rigor in its educational activities. Course Director(s), Planning Committee Members, Faculty, and all others

who are in a position to control the content of this educational activity are required to disclose all relevant financial relationships with

any commercial interest related to the subject matter of the educational activity. Safeguards against commercial bias have been put in

place. Faculty also will disclose any off label and/or investigational use of pharmaceuticals or instruments discussed in their

presentation. Disclosure of this information will be published in course materials so those participants in the activity may formulate

their own judgments regarding the presentation.

Critical Care Grand Rounds Disclosure Summary Continued


Learning Objectives

• Interpret ultrasound findings of the inferior vena cava in critically ill patients.

• Translate ultrasound findings of the inferior vena cava to clinical management of critically ill patients.

• Identify the limitations of using ultrasound guided fluid resuscitation.


Introduction

• Care of the critically ill patient involves:

• Rapid diagnosis

• Targeted treatment of underlying pathologywhile

• Supporting organ function and

• Avoiding iatrogenic harm


Introduction

• A Major Tenet of Critical Care:

• Optimization of cardiovascular function:

• Vasopressive/inotropic medication

• Mechanical ventilation

• Hemoglobin/oxygen carrying capacity of blood

• Fluid intervention/resuscitation


Introduction

• Increased use of ultrasound in the Intensive Care Unit (ICU)

• Technological advances

• Greater affordability

• Safe

• Rapid

• Non-invasive

• Repeatable


Introduction

• Inferior Vena Cava Guided Fluid Resuscitation

• Many investigators/publications

• Various IVC US parameters demonstrated

• But conclusions are conflicting and medical opinions are not unanimous.


Introduction

• In this Pro – Con Debate, we aim to

• Enhance your understanding of the US derived IVC parameters

• Explore the controversies of this modality in the care of the critically ill

• Enable you to arrive at YOUR conclusions for YOUR practice.


Assessment of the Inferior Vena Cava using ultrasound is useful in guiding fluid resuscitation.

A. Yes

B. No

A. B.

0%0%


Intensivists should routinely use ultrasound assessment of the IVC to guide fluid resuscitation in critically ill patients.

A. Yes

B. No

A. B.

0%0%


Inferior Vena Cava Guided Fluid Resuscitation

PROBrian Beam


Premise #1

• Determining the intravascular volume status of critically ill patients is DIFFICULT

• And not something we always do well


Dry, Wet or Just Right

HypovolemiaHypervolemia

Optimal Tissue Perfusion

Chinn (Producer) & Marsh (Director). (2008). Man on

Wire [Motion Picture]. USA: Magnolia.


http://www.express.co.uk/news/weird/164768/Tightrope-walker-trips-1-600ft-in-the-air

Mohsenin. J of Critical Care (2015) Epub ahead of Print.

http://www.express.co.uk/news/weird/164768/Tightrope-walker-trips-1-600ft-in-the-air


Dry, Wet or Just Right

Chinn (Producer) & Marsh (Director). (2008). Man on Wire

[Motion Picture]. USA: Magnoliahttp://www.express.co.uk/news/weird/164768/Tightrope-walker-

trips-1-600ft-in-the-air


Determining Volume Status:Tools of the Trade

Risk-Potential for

Harm

Benefit-Diagnostic Yield

• History

• Exam

• Non-Invasive

monitors

• Labs

• Ultrasound

• Invasive monitors


Premise #2

• We must thoroughly understand the diagnostic tools we plan to utilize.

• If we don’t then we as providers WILL make errors in therapeutic decision making

JAMA 1990; 264:2928-32.


Premise #3

• The best clinicians make decisions after synthesizing the entire clinical picture!


Premise #4

• Ultrasound is a tool that holds tremendous potential to assist in clinical decision making in critically ill patients.

http://www.intropsych.com/ch07_cognition/learning_curve.html


Focused Transthoracic Ultrasound

European Journal of Anaesthesiology 2004; 21: 700-707)


Premise #5

• “Static” measurements which attempt to infer intravascular volume status are generally poor predictors of intravascular volume

Shippey. Critical Care Med. 1984. Vol 12. No 2.


Premise #5

• “Static” measurements which attempt to infer intravascular volume status are generally poor predictors of intravascular volume

• *Except maybe at the extremes*

Shippey. Critical Care Med.

1984. Vol 12. No 2.


Static Measurement of IVC

• Cadaveric Study of 69 Livers

• Examined retrohepatic segment of IVC

• Median Diameter of IVC was 2.3 cm (range 1.5 to 8.2 cm)

Indian J Gastroenterol 2009(November–December):28(6):216–220

Image from: http://thesocietypages.org/socimages/2014/07/page/3/


Premise #6

• Dynamic indices of intravascular volume are more helpful in guiding fluid administration

Pulse Pressure

Variation

Dynamic Changes

of IVC diameter

Dynamic changes in aortic

flow velocity/stroke volume

assessed by Doppler methods End-expiratory

occlusion test

Dynamic changes of

the plethysmographic

waveform

Passive leg

raising


Ultrasound of the IVC

Images from:

https://web.stanford.edu/group/ccm_echocardio/cgi-bin/mediawiki/index.php/IVC

http://echocardiographer.org/TTE.html

http://echocardiographer.org/TTE.html


Dynamic Changes in IVC Diameter: The Physiology

Utilizes the interplay between the compliance of the IVC and cyclical

changes in intra-thoracic pressure during the respiratory cycle



Images from: https://web.stanford.edu/group/ccm_echocardio/cgi-

bin/mediawiki/index.php/IVC



Image from: https://web.stanford.edu/group/ccm_echocardio/cgi-

bin/mediawiki/index.php/IVC



Abdomen Thorax



Bodson and Vieillard-Baron Critical Care 2012, 16:181

Unfortunately,

the Devil is in the Details

Spontaneous Mechanical Ventilation

• Normal

• Increased Intra-Ab

Pressure


Dynamic Changes in IVC Diameter

• The IDEAL STUDY

• Enrolls critically ill patients with hemodynamic instability and uncertainty regarding intravascular volume status

• Accurately performs measurement of dynamic change in IVC diameter

• Accurately measures change in stroke volume after fluid challenge


Spontaneously Breathing Patients- Corl

• 30 spontaneously breathing ED patients suspected to be hypovolemic

• No correlation between fluid responsiveness and IVC Index

Emergency Medicine Australasia (2012) 24, 534–539


Spontaneously Breathing Patients- Muller

• 40 spontaneously breathing ICU pts with circulatory failure

• Measured IVC 2-3 cm from the right atrium

• Responsiveness: 15% increase in subaortic velocity time index (VTI) after 500 mL Hetastarch bolus

• cIVC = (Dmax-Dmin)/Dmax x 100

• Cutoff: cIVC 40%

• PPV 72%

• NPV 83%

Critical Care 2012, 16:R188


Spontaneously Breathing Patients- Lanspa

• 14 spontaneously breathing ICU patients with early sepsis

• Measured IVC prox to hepatic veins (0.5-3 cm from RA junction)

• Volume Responsiveness: >15% increase CI after 10 ml/kg bolus

• cIVC= (Dmax-Dmin)/Dmax x 100

• Cutoff: cIVC 15%

• PPV 62%

• NPV 100%

Shock. 2013 Feb;39(2):155-60


Spontaneously Breathing Patients-Conclusion

• cIVC >40% - Fluid responsive- maybe

• cIVC <15% - NOT fluid responsive

cIVC= (Dmax-Dmin)/Dmax x 100


Mechanically Ventilated Patients- Moretti

• 29 patients with SAH. Intubated, sedated, paralyzed. MV, TV= 8 mL/kg

• IVC measured 2 cm caudal from suprahepatic vein

• Responsiveness: 15% increase in CI after 7 ml/kg Hetastarch bolus

• dIVC= (Dmax-Dmin)/Dmin x 100

• Cutoff: dIVC 16%

• PPV 70.5%

• NPV 100%

Neurocrit Care (2010) 13:3-9


Mechanically Ventilated Patients- Barbier

• 20 patients with severe sepsis. MV, TV 8.5 ml/kg, PEEP 4

• IVC measured upstream from suprahepatic vein

• Volume Responsiveness: 15% increase in CO after 7 ml/kg plasma expander

• dIVC= (Dmax-Dmin)/Dmin x 100

• Cutoff: dIVC 18%

• PPV 90%

• NPV 90%

Intensive Care Med (2004) 30:1740–1746


Mechanically Ventilated Patients- Feissel

• 39 patients in septic shock. MV, TV 8-10 mL/kg

• IVC measured 3 cm from RA

• Volume Responsiveness: 15% increase in CO after 8 ml/kg Hetastarch bolus

• ∆IVC= (Dmax-Dmin)/[(Dmax + Dmin)/2] x 100

• Cutoff: ∆IVC 12%

• PPV 93%

• NPV 92%

Intensive Care Med (2004) 30:1834–1837


Mechanically Ventilated Patients:Conclusion

• In hemodynamically unstable patients who are mechanically ventilated without spontaneous respiratory effort and TV ≥8 ml/kg

• dIVC >18% - fluid responsive

• dIVC <16% - NOT fluid responsive

• What about ∆IVC cutoff of 12%?

dIVC= (Dmax-Dmin)/Dmin x 100

∆IVC= (Dmax-Dmin)/[(Dmax + Dmin)/2] x 100


Mechanically Ventilated Patients:Simplified Conclusion

• In hemodynamically unstable patients who are mechanically ventilated without spontaneous respiratory effort and TV ≥8 ml/kg

• dIVC >20% - likely fluid responsive

• dIVC <10% - likely NOT fluid responsive

dIVC= (Dmax-Dmin)/Dmin x 100


Conclusion

• Determining optimal intravascular volume status of ICU patients is difficult

• Evaluation of the dynamic changes of the IVC with respiration is a low risk and readily available tool that can provide useful information in the appropriate clinical settings


Image from: http://jeffreyhill.typepad.com/english/2010/10/cartoon-throwing-the-baby-out-with-the-

bathwater.html

Limitations

IVC

US


Inferior Vena Cava Guided Fluid Resuscitation

CONHon Liang Tan


Setting boundaries

• I submit:

• An extremely small/flat IVC or high IVC-CI likely indicates hypovolemia in the correct clinical context.

• An extremely large IVC or low IVC-CI is likely to indicate hypervolemia in the correct clinical context.


Setting boundaries

• But:

• "Correct clinical context" may be obvious to the experienced clinician


Defining the Case

• Thus,

• What we want to know is if it is useful in grey zones / difficult cases.

• Limited/no value for difficult cases.

• In the hands of an inexperienced, it might even be dangerous weapon.


Inferior Vena Cava Guided Fluid Resuscitation - Con

• What is the logic?

• What’s wrong with the logic?

• Why is the evidence contradictory?

• So why bother?


What is the logic?

• The logic:

• IVC connected to right atrium

• Compliant IVC

• Distention = intra-luminal pressure = right atrium pressure


What is the logic?

• Correlation demonstrated. Or was it?

• 83 patients: US assessment followed by “floatation catheter” within 24 hours.

• RA pressure (range 0 to 28 mm Hg)

IVC Characteristic Correlation Coefficient

Expiratory Diameter 0.48

Inspiratory Diameter 0.71

Percentage Collapse 0.75


What is the logic?

• Percentage Collapse:

• Discrimination of RA pressure > 10 mm Hg maximized at 50% level of collapse.

• Wonderful!

• Or it is?


What’s wrong with the logic?

• It does not account for:

• Patient characteristics

• Intra-luminal factors

• Extra-luminal factors

• Operator/technical factors

• Problems with measurement




• Patient POSITION

• American Society of Echocardiography (ASE)

• Left lateral decubitus



• In ICU, what do we do?

• Supine, head up 30 degrees!

• IVC changes shape in different positions.

• IVC larger in supine than in left lateral.




• Changes of the IVC with AGE

• 200 patients : 17 to 94 years old.

• Age

• Inversely correlated with IVC diameter.

• Proportionally increases IVC-CI.




• ETHNICITY/PHYSIQUE of patients (Asian)

• IVC > 19mm = RAP >10mmHg (sensitivity, 75%; specificity, 78%)

• IVC-CI > 30% (sensitivity, 75%; specificity, 83%).




• LIVER DISEASE

Max IVC Diameter (cm) IVC Reduction (cm) Sniff

Normal 2.35 +/- 0.34 1.30 +/- 0.67

Cirrhotic 1.74 +/- 0.35 0.03 +/- 0.09




• Right ventricular compliance

• Tricuspid valve disease

• Obstruction distal to right atrium

• Blood flow diversion




• RV COMPLIANCE/DIASTOLIC FAILURE

• Close correlation between LV and RV diastolic parameters.




• RV COMPLIANCE/DIASTOLIC FAILURE

• > 1/3 have LV diastolic dysfunction on admission.

• >1/3 develop reversible diastolic dysfunction at least once during admission.




• TRICUSPID VALVE DISEASE

• Tricuspid Regurgitation/Stenosis

• OBSTRUCTION DISTAL TO RIGHT ATRIUM

• Pulmonary valve disease

• Pulmonary Hypertension

• Numerous causes

• Tumor




• BLOOD FLOW DIVERSION

• Pathological states – portosystemic shunts

• Relationship between IVC parameters and volume status in such situations has not been validated




• Intra-thoracic pressure

• Spontaneous vs mechanical ventilation

• Intra-pericardial pressure

• Intra-abdominal pressure




• INTRA-PERICARDIAL PRESSURE

• Cardiac tamponade

• INTRA-THORACIC PRESSURE

• Tension pneumothorax

• Spontaneous vs mechanical ventilation





• Spontaneous ventilation

• Respiratory pattern

• Abdominal/diaphragmatic breathing resulted in greater IVC-CI compared to thoracic breathing





• Spontaneous ventilation

• "Sniff Test”

• Unable to standardize patient effort

• Respiratory distress

• Tidal volume

•





• Mechanical ventilation

• Paralysis? Mode?

• Chest wall / lung compliance?

• Tidal volume (8-10 ml/kg) / PEEP?

12%

18%




• INTRA-ABDOMINAL PRESSURE

• Intra-Abdominal Hypertension

• 32-56%

• Abdominal Compartment Syndrome

• 2-10%

• Conversely, open abdomen?




• Technical difficulties in assessing the IVC

• Potential error in measurement

• Inter-operator variability

• Site of measurement




• TECHNICAL DIFFICULTIES

• Impossible in up to 18% of patients




• TECHNICAL DIFFICULTIES

• IVC moves

• Vertically by 21.9 mm

• Horizontally by 3.9 mm

• M mode not measuring same point.




• ERRORS IN MEASUREMENT

• Foreshorten views




• ERRORS IN MEASUREMENT

• IVC-CI = Max diameter – Min Diameter

Max Diameter

• Small error (in mm) results in large changes


Spontaneous Breathing PatientcIVC= (Dmax-Dmin)/Dmax x 100

cIVC >40% - Fluid responsive

cIVC ≤15% - NOT fluid responsive

Mechanically Ventilated patient, no

respiratory effort, TV 8-10 mL/kgdIVC= (Dmax-Dmin)/Dmin x 100

dIVC >18% - fluid responsive

dIVC <16% - NOT fluid responsive

∆IVC= (Dmax-Dmin)/[(Dmax + Dmin)/2] x 100

∆IVC >12% - fluid responsive

∆IVC <12%- NOT fluid responsive




• SITE OF MEASUREMENT

• IVC collapses unequally





• IVC collapses unequally

• Different site of measurement = different dimensions

• Long axis view from lateral trans-hepatic window may make the IVC appear to collapse less





• No consensus of where to measure.

• ASE: 0.5 – 3 cm from right atrium.




• INTER-OPERATOR VARIBILITY

• Inter-operator agreement among trained ED physicians is moderate.


Why is the evidence contradictory?

• Studies do not uniformly account for:






So why bother?

• Multiple confounders/factors affect IVC parameters

• Purported IVC parameters cut offs overlap significantly

• Exact values cannot be established with certainty

• Can lead to erroneous conclusions

• No evidence to show better outcomes


So why bother?

• Even if RAP = CVP

• So what??


Conclusion

• Ultrasound assessment of IVC is NOT useful in guiding fluid resuscitation when it matters most.

• Routine assessment of IVC in the critically ill patient is NOT necessarily diagnostic or warranted.


Post Debate Evaluation

*High stakes*


Assessment of the Inferior Vena Cava using ultrasound is useful in guiding fluid resuscitation.

A. Yes

B. No

A. B.

0%0%


Intensivists should routinely use ultrasound assessment of the IVC to guide fluid resuscitation in critically ill patients.

A. Yes

B. No

A. B.

0%0%


Questions & Discussion

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