Selection of acute blood purification therapy according to lipid mediator adsorption and blood purification in patients with septic shock

Introduction

Direct hemoperfusion using a polymyxin B-immobilized fiber column (DHP-PMX) has been used for the treatment of septic shock. As an alternative method for acute blood purification therapy, continuous venovenous hemodiafiltration (CVVHDF) has been reported to be an effective clinical treatment for critically ill patients; however, the optimal column for performing CVVHDF remains controversial. On the other hand, recently, one of the lipid mediators, endocannabinoids (N-arachidonoylethanolamine (AEA) and 2-arachidonoyl glycerol (2-AG)) have been reported with a blood pressure decreased effect.

Methods

We investigated 14 polymethylmethacrylate (PMMA) membrane hemofilters and three polyacrylonitrile (PAN) membrane hemofilters after use in patients with septic shock. Therefore, in clinical study, we used CVVHDF after DHP-PMX to treat 32 patients with septic shock. To determine the optimal acute blood purification therapy, we subsequently divided the patients into two groups: group A underwent CVVHDF using a PMMA membrane hemofilter after undergoing DHP-PMX (n = 25); group B underwent CVVHDF using a PAN membrane hemofilter after undergoing DHP-PMX (n = 7). In addition, the levels of endocannabinoids (AEA, 2-AG) were measured. The severity scores and the improvement of endocannabinoids were compared between the two groups.

Results

Endocannabinoids (AEA, 2-AG) were adsorbed more in the PMMA column (AEA; 506.3 ± 680.2 ng/column, 2-AG; 23.0 ± 38.5 μg/column) than in the PAN column (AEA; 1.5 ± 0.7 ng/column, 2-AG; 0.1 ± 0.1 μg/column). The average Acute Physiology and Chronic Health Evaluation (APACHE) II score and the average sepsis-related organ failure assessment (SOFA) score did not differ significantly between the two groups. Group A showed a better outcome compared with Group B (P = 0.05). In addition, only group A showed a significant improvement in the blood AEA level on day 1 (P = 0.0185).

Conclusions

Our study suggests that the PMMA column might be the better column for performing CVVHDF after DHP-PMX treatment, as suggested by the adsorption and blood purification of endocannabinoids.