A clinical randomized study on the effects of invasive monitoring on burn shock resuscitation.

BACKGROUND: Ever since Charles Baxter's recommendations the standard regime for burn shock resuscitation remains crystalloid infusion at a rate of 4 ml/kg/% burn in the first 24h following the thermal injury. A growing number of studies on invasive monitoring in burn shock, however, have raised a debate regarding the adequacy of this regime. The purpose of this prospective, randomised study was to compare goal-directed therapy guided by invasive monitoring with standard care (Baxter formula) in patients with burn shock.

PATIENTS AND METHODS: Fifty consecutive patients with burns involving more than 20% body surface area were randomly assigned to one of two treatment groups. The control group was resuscitated according to the Baxter formula (4 ml/kg BW/% BSA burn), the thermodilution (TDD) group was treated according to a volumetric preload endpoint (intrathoracic blood volume) obtained by invasive haemodynamic monitoring.

RESULTS: The baseline characteristics of the two treatment groups were similar. Fluid administration in the initial 24h after burn was significantly higher in the TDD treatment group than in the control group (P = 0.0001). The results of haemodynamic monitoring showed no significant difference in preload or cardiac output parameters. Signs of significant intravasal hypovolemia as indicated by subnormal values of intrathoracic and total blood volumes were present in both treatment groups. Mortality and morbidity were independent on randomisation.

CONCLUSION: Burn shock resuscitation due to the Baxter formula leads to significant hypovolemia during the first 48 h following burn. Haemodynamic monitoring results in more aggressive therapeutic strategies and is associated with a significant increase in fluid administration. Increased crystalloid infusion does not improve preload or cardiac output parameters. This may be due to the fact that a pure crystalloid resuscitation is incapable of restoring cardiac preload during the period of burn shock.