cc5798 CCJ Poster presentation <p>Dynamic evaluation of central venous pressure for fluid responsiveness assessment in spontaneous breathing dogs</p> Silva E Rehder P Westphal GA

Division of Applied Physiology, Heart Institute, InCor, University of São Paulo Medical School, São Paulo – SP, Brazil

 Critical Care <p>Fourth International Symposium on Intensive Care and Emergency Medicine for Latin America</p> Meeting abstracts http://ccforum.com/supplements/notes/ccv11s3-info.pdf <p>Fourth International Symposium on Intensive Care and Emergency Medicine for Latin America</p> São Paulo, Brazil 20–23 June 2007 1364-8535 2007 11 Suppl 3 P11 http://ccforum.com/content/11/S3/P11 10.1186/cc5798 19 6 2007 2007 BioMed Central Ltd

Background

Variations in intrathoracic pressure interfere with venous return and cardiac output (CO). Inspiratory fall in central venous pressure (CVP) traces (ifCVP) during spontaneous breathing have been recommended for cardiovascular fluid responsiveness (CFR) evaluation. We recently described the usefulness of CVP wave amplitude variation (pressoric vena cava collapsibility index, Cvci) during mechanical ventilation for CFR estimation in critically ill patients. There are no data about the Cvci evaluation during spontaneous breathing.

Objective

To test the hypothesis that Cvci can be used for CFR evaluation during spontaneous ventilation.

Methods

In six male, anesthetized, intubated and spontaneous breathing dogs, CO measurements and CVP waves were registered through a Swan–Ganz catheter while the mean arterial pressure (MAP) was measured through an intraarterial catheter.

After baseline measurements a graded hemorrhage was performed in 10% quota until 50% of the estimated volemia. The total shed blood volume was then re-infused in the same quota. Measurements of the heart rate (HR), CO, MAP, CVP, ifCVP, and Cvci are performed in every bleeding and re-infusion step. The Cvci was calculated with the following formula: Cvci(%) = [(CVPPexp - CVPPins)/CVPPexp] × 100, using the inspiratory (CVPPins) and expiratory central venous pulse pressure (CVPPexp). ifCVP = CVP measured in the 'a' wave base at expiration minus CVP measured in the 'a' wave base at inspiration. Correlations among the CO and other variables were performed using the Spearman coefficient test.

Results

See Table 1. The correlations encountered were: CO and SvO2 (r = 0.94, P < 0.001); CO and Cvci (r = 0.61, P < 0.04); and CO and ifCVP (r = -0.02, P < 0.9).

<p>Table 1</p>

Step

0

-10%

-20%

-30%

-40%

-50%

-40%

-20%

0

CO

2.8 ± 0.5

2.4 ± 0.4

2.2 ± 0.4

1.8 ± 0.5

1.6 ± 0.5

1.4 ± 0.5

1.8 ± 0.4

3.0 ± 0.7

3.5 ± 0.8

ifCVP

2.8 ± 0.4

3.1 ± 0.5

3.8 ± 0.7

3.3 ± 0.5

2.1 ± 0.2

2.7 ± 0.5

4.1 ± 1

3.0 ± 0.5

2.3 ± 0.2

Cvci

-8 ± 6

-11 ± 13

-19 ± 8

-18 ± 15

-27 ± 10

-17 ± 7

-12 ± 20

-11 ± 7

-8 ± 4

Conclusion

We conclude that a pressoric vena cava collapsibility index may be used to detect cardiovascular fluid responsiveness during spontaneous ventilation.