Monitoring trauma patients with total bioelectrical impedance

Introduction

Volume support is frequently required in critically ill patients with hypovolemia due to severe trauma. Aggressive intravenous therapy may cause serious dislocations of body water compartments, and the degree of expansion of the extracelular water compartment may influence outcome in trauma patients. We used total bioelectrical impedance (TBI) to detect the development of edema and fluid redistribution in more severe trauma patients.

Methods

Prospective clinical study in a 24-bed ICU from a university hospital.

Measurements and results

Severity scores often used in trauma patients together with TBI variables (resistance and reactance) were prospectively evaluated in 33 consecutive trauma patients (12 died and 21 survived). TBI was performed on ICU admission and after 72 h. Fluid intake and output were measured daily. Severity scores, resistance (R) and net fluid intake are shown in the Table.

Table

Conclusion

A pattern of decreasing resistance was found in nonsurvivor patients, reflecting an increased distribution volume. Higher values of net fluid balance in nonsurvivors are due to higher amounts of intravenous fluid therapy used in more severe trauma patients. TBI may help evaluate body fluid compartments in trauma patients, and may also be helpful in identifying high-risk patients who would benefit from more aggressive therapeutic interventions.