The immunological effects of continuous veno-venous haemodiafiltration in critically ill patients

Background: Haemodynamic instability is common in septic patients with acute renal failure. Continuous veno-venous haemodiafiltration (CVVHD) is therefore used as an alternative to conventional haemodialysis. Haemodialysis is associated with an activation of the immune system. The aim of the present study was to test the hypothesis that initiation of CVVHD influences the immune system with release of proinflammatory cytokines followed by a decrease in granulocyte activation, as assessed by the expression of adhesion molecules.

      Results:
      Fifteen patients were included. Mean Acute Physiology and Chronic
			Health Evaluation-2 score before CVVHD was 19 (range 8⌓27). Mean duration of
			CVVHD treatment was 9 days (1⌓21 days). Tumour necrosis factor-α and
			interleukin-8 were detectable in plasma in all patients, whereas interleukin-10
			was detectable only in a few patients. Proinflammatory and anti-inflammatory
			cytokines were detected in the ultrafiltrate. Large intraindividual and
			interindividual variations were demonstrated for all of the immunological
			parameters studied.
    
    
      Conclusion:
      The hypothesis that CVVHD induces the release of proinflammatory
			cytokines followed by a decrease in granulocyte activation was not confirmed in
			the present study. The heterogeneous group of patients studied, with different
			underlying diseases and various durations of illness before the start of CVVHD,
			might have contributed to the difficulty in demonstrating the proposed
			immunological effect of CVVHD.