Should echographic examination of the inferior vena cava be trusted to assess fluid responsiveness in ASA 1 and 2 volunteers?

Resumo

Introduction: Fluid responsiveness is a fundamental concept in the management of perioperative fluid therapy, and an integrating part of most goal-directed therapy protocols. Transthoracic echocardiography is a non-invasive technology that allows assessment of this characteristic, with the most validated echocardiographic parameter for individuals breathing spontaneously being aortic velocity time integral (VTI) variation with the passive leg raise manoeuvre (PLR). However, different authors also advise the use of inferior vena cava (IVC) assessment with the same goal.

Methods: In this observational, analytic, prospective study we enrolled 31 ASA 1 and ASA 2 volunteers with no cardiovascular comorbidities and performed two echocardiographic examinations in each (in different days). The relationship between IVC indices and aortic VTI variation with PLR was studied using Pearson’s correlation coefficient, Mann-Whitney test, logistic regression and the Kruskal-Wallis test.

Results: All results pointed towards the absence of a statistically significant relationship between IVC parameters and aortic VTI variation with PLR as a marker of fluid responsiveness.

Conclusion: In view of our results caution is advised when relying on IVC indices to guide fluid therapy in non-critical, spontaneously breathing individuals, although further, larger trials are needed to generalize our findings to other patient groups.