Serum IL-6 and IL-1-ra with sequential organ failure assessment scores in septic patients receiving high-volume haemofiltration and continuous venovenous haemofiltration.

AIM

Sepsis is characterized by an uncontrolled release of pro-inflammatory and anti-inflammatory mediators leading to immunoparalysis, cellular and humoral dysfunction, multiorgan dysfunction and death. This study evaluated the efficacy of high-volume haemofiltration (HVHF) compared with continuous venovenous haemofiltration (CVVH) in removing these inflammatory mediators. Clinical responses were assessed with the sequential organ failure assessment (SOFA) score.

METHODS

Septic patients with an end-organ dysfunction or septic shock were randomized to receive 6 h of CVVH (ultrafiltration dose of 2 L/h equivalent to about 35 mL/kg per hour or HVHF (ultrafiltration dose of 100 mL/kg per hour or 6 L/h, whichever was higher). The sequential organ failures were scored for the 24 hours preceding recruitment; at day 1, day 7, at discharge from the intensive care unit and at hospital discharge.

RESULTS

Thirty-three patients were enrolled. Fifteen received HVHF and 18 received CVVH. The serum IL-6 levels (pg/mL) at baseline were similarly elevated in both groups (P = 0.745). The HVHF group showed a significant reduction after 6 h of treatment with a median interquartile range (IQR) of 20.62 (49.21) pg/mL (P = 0.025) with no similar result in the CVVH group. Non-survivors showed a higher baseline serum IL-6 compared with the survivors (median (IQR) 172.31 (261.34) vs 58.9 (104.21), P = 0.044). In the HVHF group there was a positive association between the IL-6 levels at 6 h with the SOFA scores at day 1 (r = 0.392, P = 0.001) but not at day 7. After 6 h of treatment in the HVHF group there was a direct correlation between the IL-6 levels and number of hospital days (r = 0.90, P = 0.040). The maximum SOFA scores were persistently recorded before treatment. The SOFA scores reduced in both groups from baseline to day 7 (HVHF P = 0.048; CVVH P = 0.006). The SOFA scores at day 1 is significantly higher in the non-survivors compared with the survivors (P = 0.038).

CONCLUSIONS

High-volume haemofiltration at 6 L/h may seem to successfully remove some inflammatory cytokines in septic patients. The improvement in the SOFA scores at day 7 promises benefit of continuous renal replacement therapy in septic patients, but after 20 days this effect may be lost. In addition, the baseline serum IL-6 and IL-1-ra were independent predictors of a poor outcome as reflected by the higher SOFA scores at day 1.