Haemofiltration In Sepsis Tom Owen Mar 2006

Overview Rationale for CVVH use in sepsis Evidence of effectiveness Newer therapies Summary

Pathophysiology of Sepsis

Pathophysiology of Sepsis Complicated!! Release of over 100 mediators Pro- and anti-inflammatory Overlapping functions ‘Specific’ therapies ineffective

CVVH

CVVH – Why Might It Work? Convection versus diffusion Better clearance of ‘middle molecules’ Adsorption onto membrane Non-specific

What Ultrafiltration Rate? Ronco et al, Lancet, 2000 ‘Landmark Study’ 20ml/kg/hr – 41% survival (25% in Sepsis) 35ml/kg/hr – 57% survival (19% in Sepsis) 45ml/kg/hr – 58% survival (47% in Sepsis)

High Volume Haemofiltration Theoretical advantage in the septic patient Peak Concentration Hypothesis – degree of insult depends on the peak concentration of cytokines Lack of evidence that concentrations are decreased

HVHF –The Evidence Infusion of ‘septic’ ultrafiltrate into healthy pigs causes sepsis Numerous animal studies show improved haemodynamics with HVHF Oudemans et al, Int Care Med 1999 Cohort analysis, 306 patients Better than predicted mortality

HVHF – The Evidence (3) Honore et al, Crit Care Med 2000 35l in 4hrs then conventional CVVH 9/11 survivors in responders 0/9 survivors in non-responders Cole, Bellomo et al, Int Care Med 2001 1l/hr vs 6l/hr CVVH Decreased norad requirements and cytokine levels in HVHF

HVHF – The Evidence (4) Ratanarat et al 2005 Piccinni et al, 2006 PHVHF – 85ml/kg/hr for 6-8hrs then 35ml/kg/hr Improved haemodynamics that were maintained ??improved survival Piccinni et al, 2006 Early 45ml/kg/hr CVVH for 6 hrs Improved gas exchange, MAP, weaning, 28 day survival and shorter ICU stay

HVHF - Limitations Cost Increased workload Potential for fluid/electrolyte imbalance ? Interaction with APC

Future Directions Continuous haemoperfusion Continuous plasmafiltration coupled with adsorption

Summary High Volume Haemofiltration appears promising The earlier the better Pulse – HVHF helps to avoid some of its limitations Haemoperfusion may well have a role RCT’s needed!!

And Relax………