Volume 2 Supplement 1

ESICM LIVES 2014

Open Access

0590. Impact of arterial tone changes on dynamic arterial elastance and the arterial pressure response to fluid administration

  • MI Monge García1, 2,
  • M Gracia Romero2,
  • P Guijo González2,
  • A Gil Cano2,
  • J Mesquida3,
  • R Andrew1,
  • RM Grounds1 and
  • M Cecconi1
Intensive Care Medicine Experimental20142(Suppl 1):P35

DOI: 10.1186/2197-425X-2-S1-P35

Published: 26 September 2014

Introduction

Dynamic arterial elastance (Eadyn), the relationship between pulse pressure variation (PPV) and stroke volume variation (SVV), has been suggested as a functional assessment of arterial load for predicting the arterial pressure response after volume expansion (VE)1. Although changes in Eadyn have been related with variations in arterial load2, the effect of acute arterial tone changes on Eadyn and the impact on its performance for predicting the arterial pressure response after VE has not yet been determined.

Objective

To evaluate the effect of acute arterial tone changes on Eadyn and the influence on its performance for predicting arterial changes after fluid administration.

Methods

12 anesthetized and mechanically ventilated rabbits. Arterial tone changes were induced by phenylephrine (PHENY) infusion on 6 animals (HighMAP group) and by sodium nitroprusside (SNP) on the other 6 animals (LowMAP group), until reach a 50% of change on mean arterial pressure (MAP) from its baseline value. A volume challenge (10 mL/Kg) was then performed on all animals. Animals were monitored with an indwelling femoral arterial catheter and an esophageal Doppler (CardioQ-Combi). Arterial load was assess by the systemic vascular resistance, net arterial compliance and effective arterial elastance. Eadyn was calculated as the simultaneous ratio between PPV and SVV obtained from the Doppler monitor.

Results

At baseline, Eadyn and other arterial load parameters were similar on both groups. In the LowMAP group, SNP significantly decreased arterial load, reduced MAP by 44%, and consistently increased Eadyn by 75% (Figure 1). In the HighMAP group, PHENY increased arterial load, raised MAP by 58%, and significantly reduced Eadyn by 41% (Fig. 1 and 2). Overall, VE increased cardiac output by 10%, stroke volume by 21% and MAP by 15%, and decreased Eadyn from 1.08 ± 0.67 to 0.88 ± 0.45 (Fig.1). There was a significant relationship between Eadyn after arterial tone changes and increases in all components of arterial pressure after VE: systolic (R2=0.89), diastolic (R2=0.41), mean arterial (R2=0.61) and pulse pressure (R2=0.67), respectively. Animals with a MAP increase ≥ 10% after VE had a higher preinfusion Eadyn value (1.54 ± 0.49 vs. 0.46 ± 0.15; P < 0.001).
https://static-content.springer.com/image/art%3A10.1186%2F2197-425X-2-S1-P35/MediaObjects/40635_2014_Article_92_Fig1_HTML.jpg
Figure 1

SVV and PPV example on HighMAP group.

https://static-content.springer.com/image/art%3A10.1186%2F2197-425X-2-S1-P35/MediaObjects/40635_2014_Article_92_Fig2_HTML.jpg
Figure 2

SVV and PPV example on LowMAP group.

Table 1

Comparison of arterial load parameters during different experimental conditions in HighMAP abnd LowMAP groups (n=6 on both experimental arms).

 

Baseline

After change in arterial pressure

Postinfusion

P valuea

EA dyn

    

HighMAP

0.92 ± 0.12

0.52 ± 0.23*

0.49 ±.0.18

<0.001

LowMAP

0.91 ± 0.16

1.64 ± 0.44*

1.26 ± 0.22*

 

Ea, cmHg/mL

    

HighMAP

3.99 ± 0.93

5.42 ± 1.46*

4.45 ± 1.11

<0.001

LowMAP

4.50 ± 1.44

1.80 ± 0.63*

1.52 ± 0.50†*

 

C, mL/cmHg

    

HighMAP

0.66 ± 0.13

0.41 ± 0.10*

0.48 ± 0.08†*

<0.001

LowMAP

0.53 ± 0.16

1.92 ± 0.86*

1.83 ± 0.58*

 

TVSR, MPa's/m 3

    

HighMAP

1514 ± 453

3157 ± 1299*

3372 ± 1306*

<0.001

LowMAP

1814 ± 585

709 ± 215*

720 ± 218*

 

C: new arterial compliance; Ea: effective arterial elastance; Eadyn: dynamic arterial elastance; TSVR: total systemic vascular resistance. Data are presented as mean ± standard deviation. Data normally distributed according to Kolomogorov-Smirnov test. Note that pressure units are expressed as cmHg for convenience. *p<0.05 vs baseline. p<0.05 vs. change in arterial pressure. *p value refers to ANOVA test for time and group interaction

Conclusions

In this experimental settings acute modifications on arterial tone induced significant changes on Eadyn: arterial vasodilation increased Eadyn, whereas vasoconstriction decreased it. Nevertheless, preinfusion Eadyn still determined the arterial pressure response after volume administration.

Authors’ Affiliations

(1)
St. George's Healthcare NHS Trust and St George's University of London, Department of Intensive Care Medicine
(2)
Hospital SAS de Jerez, Servicio de Cuidados Intensivos y Urgencias
(3)
Universitat Autónoma de Barcelona, Consorci Sanitari Universitari Parc Tauli

References

  1. Monge Garcia MI, Gil Cano A, Gracia Romero M: Dynamic arterial elastance to predict arterial pressure response to volume loading in preload-dependent patients. Crit Care 2011, 15: R15. 10.1186/cc9420PubMed CentralPubMedView ArticleGoogle Scholar
  2. Hadian M, Severyn DA, Pinsky MR: The effects of vasoactive drugs on pulse pressure and stroke volume variation in postoperative ventilated patients. Journal of critical care 2011,26(328):e321–328.Google Scholar

Copyright

© García et al; licensee Springer. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Advertisement