ABSTRACTS from 16th International COnference on ... - CRRT Online

A01
Assessing the Microcirculation
Etienne Macedo MD, PhD
4:00-5:30
Tuesday, February 14
Educational Objectives:
1. Discuss the different methods for evaluating the microcirculation
2. To review the different scores available for microcirculation analysis, and which measurements should be included.
3. Discuss how monitoring of the microcirculation may help us at the bedside
Content Description:
Microvascular perfusion plays an important role in the development of organ failure in hospitalized patients.
Although microcirculation is the primary site of oxygen and nutrient exchange, microvascular oxygen delivery
cannot be predicted <strong>from</strong> global hemodynamic measurements. Hemodynamic assessment has been limited to
measurements of cardiac output and oxygen delivery, which are indirect measurements of microcirculation.
However, several observational studies and randomized controlled trials trying to improve these parameters based
on information derived <strong>from</strong> pulmonary artery catheter have shown no benefits in outcomes.
In critically-ill patients improvement in microvascular perfusion should be to one of the major therapeutic goals.
Recent advances in technology have allowed direct visualization of the microcirculation. The octagonal polarization
spectral (OPS) and the side stream dark field (SDF) imaging devices provide high contrast images of the
microvasculature. Experimental studies have shown alterations in the microcirculation common to different pathological
process. OPS and SDF imaging have been used to assess microvascular alterations in many disease
processes such as: sepsis, painful crises in sickle cell disease, bacterial infection in cirrhosis, leukostasis in patients
with chronic myeloid leukemia, and changes in the volume status of hemodialysis patient. It has also been used to
assess the effect of different therapies on microcirculation in experimental animal models and in septic patients.
Additionally, in critically-ill patients with sepsis and septic shock, recent studies have correlated microcirculatory
flow abnormalities with hemodynamics, oxygen transport and survival.
The introduction of OPS and SDF imaging has opened challenging new perspectives in in vivo research of microcirculatory
alterations, and has highlighted the importance of microcirculatory alterations in multiple organ failure and sepsis.
Suggested Reading:
1. van Beers EJ, Goedhart PT, Unger M, Biemond BJ, Ince C. Normal sublingual microcirculation during painful crisis in
sickle cell disease. Microvascular Research 76:57 60, 2008.
2. Sheikh, M. Y., U. Javed, et al. Bedside Sublingual Video Imaging of Microcirculation in Assessing Bacterial Infection in
Cirrhosis. Dig Dis Sci, 2009
3. Boerma EC, van del Voort PHJ, Spronk PE, et al. Relationship between sublingual and intestinal microcirculatory perfusion
in patients with abdominal sepsis. Crit Care Med 35:1055 1060, 2007.
4. Trzeciak S, Dellinger PR, Parrillo JE, et al: Early microcirculatory perfusion derangements in patients with severe sepsis
and septic shock: Relationship to hemodynamics, oxygen transport, and survival. Ann Emerg Med 49:88-98, 2007.
5. Johannes T, Mik EG, Nohé B, et al: Influence of fluid resuscitation on renal microvascular PO2 in a normotensive rat
model of endotoxemia. Crit Care 10:R88, 2006.
6. Sakr Y, Chierego M, Piagnerelli M, et al: Microvascular response to red blood cell transfusion in patients with severe
sepsis. Crit Care Med 35:1639 1644, 2007.
7. De Backer D, Creteur J, MD, PhD; Dubois MJ, et al: The effects of dobutamine on microcirculatory alterations in
patients with septic shock are independent of its systemic effects. Crit Care Med 34:403–408, 2006.
8. Verdant C, De Backer D. How monitoring of the microcirculation may help us at the bedside. Curr Opin Crit Care
11:240-244, 2005.
9. Dobbe JGG, Streekstra GJ, Atasever B, et al: Measurement of functional microcirculatory geometry and velocity distributions
using automated image analysis. Med Biol Eng Comput 46:659-670, 2008.
10. Dubin A, Pozo M.O., Casabella Ch.A., et. Al. Increasing arterial blood pressure with norepinephrine does not improve
microcirculatory blood flow: a prospective study. Crit Care 13:R92, 2009.
11. Bemelmans R.H.H., Boerma E.Ch., Barendregt J., et al. Changes in the volume status of haemodialysis patients are
reflected in sublingual microvascular perfusion. Nephrol Dial Transplant. Advance access published June 10, 2009.
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