High volume continuous venovenous haemofiltration (HV-CVVH) in an equine endotoxaemic shock model.
Authors: Veenman J N, Dujardint C L L, Hoek A, Grootendorst A, Klein W R, Rutten V P M G
Journal: Equine veterinary journal
Summary
# High-Volume Haemofiltration in Equine Endotoxaemic Shock: Limited Efficacy in a Controlled Model Endotoxaemia secondary to acute abdominal disease remains a leading cause of shock and mortality in horses, with gut bacterial translocation and uncontrolled cytokine release driving progression; this study investigated whether high-volume continuous venovenous haemofiltration (HV-CVVH) could ameliorate these pathophysiological cascades by removing circulating inflammatory mediators. Ten Shetland ponies were anaesthetised and challenged with lipopolysaccharide (LPS) at 2 µg/kg bodyweight, with five animals receiving HV-CVVH via a 75 kD polymethylmethacrylate filter at 2 ml/kg/min for six hours whilst haemodynamic variables, routine blood work, and serum cytokine concentrations (TNF-α, IL-1 and IL-6) were measured at 30-minute intervals. Despite successful ultrafiltration and demonstrable clearance of cytokines from the blood, the treatment group showed no significant improvement in haemodynamic stability, arterial pressure maintenance, or reduction in circulating cytokine levels compared to controls, with only a modest increase in cardiac index observed. Whilst these findings suggest that HV-CVVH with PMMA membranes offers limited benefit in this relatively mild endotoxaemic model, the authors propose that greater therapeutic efficacy might be achievable using higher-severity experimental protocols or alternative filter materials with enhanced sieving coefficients. For practising clinicians, this indicates that current HV-CVVH technology may require optimisation before widespread adoption in field cases, and that further investigation into filter selection and treatment parameters
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Practical Takeaways
- •HV-CVVH using standard PMMA filters should not be considered an effective treatment for endotoxaemic shock in horses based on current evidence
- •More severe experimental models or alternative filter types may be needed to establish efficacy; do not rely on this modality in clinical practice without further supporting evidence
- •Managing endotoxaemic shock in equine acute abdominal disease requires continued focus on traditional supportive care rather than cytokine removal techniques at present
Key Findings
- •HV-CVVH with PMMA filter did not produce significant differences in haemodynamic parameters between treatment and control groups in endotoxaemic ponies
- •Cytokine clearance increased over time but did not result in significant reduction in serum TNF, IL-1, and IL-6 levels
- •Only slight increase in cardiac index and no marked decrease in mean arterial pressure were observed with HV-CVVH treatment
- •Individual variation in cytokine response was substantial despite uniform LPS challenge protocol