High-volume hemofiltration in critically ill patients: a systematic review and meta-analysis

Background. High volume hemofiltration (HVHF) has been proposed as method for blood purification, especially under the condition of systemic inflammatory syndromes. Our goal was to evaluate the effects of HVHF in critically ill patients. Methods. A systematic review and meta-analysis was conducted of randomized controlled trials containing original data comparing HVHF defined by a dose of >50 mL/kg/h versus standard volume hemofiltration in critically ill patients. The primary outcome assessed was mortality. Additional endpoints assessed were renal recovery, vasopressor dependency, cytokine reduction and adverse events. Results. Four studies investigating continuous HVHF and three studies examining pulse high volume hemofiltration (PHVHF) using prescribed doses between 62 and 85 mL/kg/h met the criteria for this systematic review and provided data eligible for meta-analysis on a total of 558 patients. Meta-analyses did not show an effect of continuous HVHF (odds ratio, OR: 0.85; 95% confidence interval [CI]: 0.50-1.45; 4 trials; N.=473) or PHVHF (OR: 0.62; 95% CI: 0.22-1.74; 3 trials; N.=85) on mortality (both combined: OR: 0.85; 95% CI: 0.60-1.22; 7 trials; N.=558). Continuous HVHF had no significant beneficial effect on renal recovery of survivors (OR: 0.62; 95% CI: 0.17-1.97; 3 trials; N.=445). Inconsistent reports of a more rapid hemodynamic stabilization or improved cytokine clearance were mainly restricted to PHVHF. Conclusion. No clear overall beneficial effect of HVHF or PHVHF compared to standard volume hemofiltration can be detected.