Morning Report

Morning Report: Fluid Responsiveness

Resident Presenter: Patrick Charles

Topic: Fluid Responsiveness Series (part 1 of 2)

Summary:
45 yo M with a PMHx of DM and HTN presents with SOB and fever. He complains of progressively worsening fatigue and cough over the last few days and developed acute onset fever, shaking chills, and difficulty breathing on the day of presentation. His vitals are 101.5oF, 132, 22, 90/44, 94% RA. Physical examination reveals right lower lung field crackles, and a chest x-ray demonstrates a right lower lobe infiltrate.

What do you do next?
Fluids?
How many liters would you empirically give this patient?
When do you pull the trigger and start pressors?

Learning Points:

  • WHAT IS FLUID RESPONSIVENESS? Is this concept synonymous with the fact that the patient needs more fluid?
    • Fluid responsiveness does not mean that a patient should be given fluids!
    • Fluid Responsiveness = An increase in their stroke volume (SV) by 10–15% via rapid infusion of 500 ml of crystalloid (fluid challenge) or straight leg raise thus improving CO if the patient falls on the preload zone of the Frank-Starling Curve.
    • If there is compressibility (or distensibility in a ventilated patient) of the IVC >20% and <50% then evaluate for fluid responsiveness. Perform a passive leg raise while
      reassessing the IVC if the IVC collapse <20% then the patient may not be a fluid responder
    • The data clearly established that there is a poor relationship between the CVP and the intravascular volume status, and no relationship between the CVP and fluid responsiveness.
    • CVP and PCWP are static tests that are less sensitive, less specific and less useful that dynamic tests (i.e. passive leg raising)
    • Preau et al: A prospective study in France that looked at 34 ICU spontaneously breathing patients. They performed passive leg raising which equates to a 500cc rapid volume expansion. They concluded that stroke volume increased >/= 10%
      after a volume expansion = passive leg raise were responders which predicted fluid responsiveness with sensitivity of 86% and specificity of 90%. The pulse pressure increase of >/= 9% which predicted fluid responsiveness with sensitivity of 79%
      and specificity of 85%. The velocity of femoral artery flow increase of >/= 8%
      which predicted fluid responsiveness with a sensitivity of 86% and specificity
      of 80%. This concluded that passive leg raising are accurate and interchangeable indices for predicting fluid responsiveness in non-intubated patients.
  • DO IVC MEASUREMENTS CORRELATE WITH CVP?
    • Kircher et al: reported that Caval Index (CI) >50% was strongly associated with a CVP <8 mm Hg and futhermore was indicative of right atrial (RA) pressures <10 mm Hg. In comparison the CI <50% was associated with a CVP >12 and indicated RA pressures >10 mm Hg
  • WHAT DO YOU DO IF THEY ARE RESPONDERS BUT REMAIN IN SHOCK?
    • (Step 1) If the CI is <50% perform a TTE and Lung US (e.g. hyperdynamic heart and no B-lines) to assess if the patient can handle more fluids.
    • (Step 2) If so add Levophed (or vasopressor of your choice).
    • (Step 3) After a few minutes repeat passive leg raise and assess if the patient is a responder.
  • LIMITATIONS OF IVC U/S
    • respirophasic changes in intrathoracic pressure are difficult to quantify when the
      inspiratory force itself cannot be measured or standardized in a spontaneous
      breathing patient
    • location at which measurements are obtained varies greatly in the literature –
      caudal to the junction of the middle hepatic vein, approximately 2 to 4 cm from
      the IVC/RA junction
    • craniocaudial movement – Mechanical displacement of the diaphragm during
      respiration frequently results in measurement of the IVC at 2 different locations
      during inspiration and expiration, and the IVC exhibits different degrees of
      collapsibility at different locations along its course
    • subcostal window may not afford adequate visualization of the IVC, particularly
      in patients with obesity, abdominal pain, gastric insufflation, large amounts of
      bowel gas, or post-surgical wounds and/or pneumoperitoneum.
    • IVC diameter and CI are significantly influenced by pulmonary hypertension,
      tricuspid regurgitation, tachycardia and variations in tidal volumes and patterns of
      respiration in spontaneously breathing patients. abdominal compartment
      syndrome

MorningReport-FluidResponsiveness- Patrick Charles Figure 2

MorningReport-FluidResponsiveness- Patrick Charles Figure 1

EBM Article:
1) Stone et al. Inferior Vena Cava Assessment, Correlation with CVP and Plethora in Tamponade. Global Heart, Vol. 8, no. 4, 2013
2) Préau et al. Passive leg raising is predictive of fluid responsiveness in spontaneously breathing patients with severe sepsis or acute pancreatitis. Crit Care Med, Vol. 38, No. 3, 2010
3) Muller et al. Respiratory variations of inferior vena cava diameter to predict fluid responsiveness in spontaneously breathing patients with acute circulatory failure: need for a cautious use. Critical Care, 16:R188, 2012
4) Marik et al. Fluid responsiveness: an evolution of our understanding, British Journal of Anaesthesia, 2014
5) Kircher et al, Noninvasive estimation of right atrial pressure from the inspiratory collapse of the inferior vena cava; Am J Cardiol. 1990 Aug 15;66(4):493-6.
6) http://lifeinthefastlane.com/ccc/fluid-responsiveness/
7) http://emcrit.org/blogpost/ivc-roundup/
8)http://www.ultrasoundpodcast.com/2013/10/integrated-ultrasound-approach-
fluid-responsiveness-canadian-style-foamed

Figures may be externally copyrighted and all rights belong with the holders.

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