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

Objective: To evaluate the effects of prophylactic veno-venous hemofiltration (CVVH) in the absence of renal failure on multiple organ dysfunction syndrome 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 contraindication for moderate heparinization. Interventions: Twelve patients received conventional treatment while 12 patients were treated additionally with isovolemic CVVH for 5 days starting within 24 h following trauma. Signs of organ dysfunction were assessed daily including monitoring of systemic hemodynamics by means of pulmonary artery catheterization during the first 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. However, the pattern of impaired organ systems was influenced by CVVH: while the post-traumatic decrease in platelet count in patients subjected to CVVH was more pronounced than in controls (e.g. day 4: control: 115,080 +/- 15,087, CVVH: 57,383 +/- 4,201 mul(-1);p < 0.05) the development of hyperdynamic circulatory failure was simultaneously attenuated, as reflected by a limited increase in cardiac output and an attenuated decrease in systemic vascular 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 platelet counts represents a limitation for the use of prophylactic CVVH in surgical patients.