Prophylactic hemofiltration in severely traumatized patients: effects on post-traumatic organ dysfunction syndrome

Objective: To evaluate the effects of prophylactic veno-venous hemofiltrati on (CVVH) in the absence of renal failure on multiple organ dysfunction syn drome after severe multiple trauma. Design: Prospective, randomized study. Setting: Intensive care unit (ICU) in a university hospital. Patients: Twenty-four patients with severe multiple trauma (injury severity score greater than or equal to 27), no renal failure on admission and no c ontraindication for moderate heparinization. Interventions: Twelve patients received conventional treatment while 12 patients were treated additionall y with isovolemic CVVH for 5 days starting within 24 h following trauma. Si gns of organ dysfunction were assessed daily including monitoring of system ic hemodynamics by means of pulmonary artery catheterization during the fir st 5 days after trauma. Measurements and main results: Prophylactic CVVH did not affect the overall severity of organ dysfunction as assessed by MOF or APACHE II scores. Howe ver, the pattern of impaired organ systems was influenced by CVVH: while th e post-traumatic decrease in platelet count in patients subjected to CVVH w as more pronounced than in controls (e.g. day 4: control: 115,080 +/- 15,08 7, CVVH: 57,383 +/- 4,201 mul(-1);p < 0.05) the development of hyperdynamic circulatory failure was simultaneously attenuated, as reflected by a limit ed increase in cardiac output and an attenuated decrease in systemic vascul ar resistance and oxygen extraction ratio (e.g systemic vascular resistance on day 4: control: 624.3 +/- 46.17, CVVH: 842.7 +/- 79.24 dyn(.)s(.)cm(-5) ; p < 0.005). Conclusion: CVVH blunts the cardiovascular response to multiple trauma and increases tissue oxygen extraction. However, the concomitant decrease in pl atelet counts represents a limitation for the use of prophylactic CVVH in s urgical patients.