Esophageal echo-Doppler monitoring in burn shock resuscitation: are hemodynamic variables the critical standard guiding fluid therapy?

BACKGROUND

Ever since the introduction of invasive hemodynamic monitoring to major burn care, its utility remains controversial. Besides complications, invasive monitoring as a guideline for burn shock resuscitation is often associated with significant excessive fluid burden. This study was to summarize the clinical experiences of noninvasive esophageal echo-Doppler (ED) monitoring in burn shock resuscitation and discuss the significance of hemodynamic variables in assessment of fluid therapeutic goal.

METHODS

Twenty-one burn patients with an average total body surface area of 78.86% +/- 7.75% (62-92%) was enrolled in this retrospective study. Fluid therapy was guided according to Chinese general formula and adjusted with urinary output 1 mL/kg/hr as resuscitation goal. Hemodynamic parameters using ED was obtained, including cardiac output (CO), stroke volume (SV), myocardial contractility parameter--maximum acceleration at onset of systole (Acc), afterload parameter--total systemic vascular resistance (TSVR), preload parameter SV/Acc.

RESULTS

All patients were clinically diagnosed with a relatively stable condition during early shock stage. There existed inherent and dynamic tendency of hemodynamics during burn shock resuscitation with low CO, Acc, SV/Acc, and high TSVR at first followed by a continuous trend of increase in CO, Acc and SV/Acc and decrease in TSVR. Significant correlations could be seen between CO and Acc, CO and TSVR, CO and SV/Acc. The Standardized Regression Coefficients of Acc, TSVR, and SV/Acc with CO as dependent variable were 0.343, -0.670, and 0.053, respectively demonstrating that myocardial contractility and angiotasis played more important role than blood volume did in hemodynamic variation.

CONCLUSIONS

Hemodynamic variables cannot routinely substitute traditional variables as the burn shock resuscitation goal. Because of its noninvasiveness, ability to real-timely provide complete profile of hemodynamics, ED monitoring is a good adjunctive method for clinical judgment.