Relationship between the use of polymyxin B-immobilized fiber for hemofiltration and some laboratory parameters (endocannabinoids, high mobility group box-1 protein and oxidative stress) in severe pneumonia patients

Introduction

Septic shock remains a major cause of multiple organ failure, with a high mortality rate, and severe pneumonia is one of the major causes of septic shock. The existence of a relationship between lung injury and the serum level of F2-isoprostane, as a known oxidative stress marker, was recently reported. The technique of direct hemoperfusion (DHP) with a polymyxin B-immobilized fiber column (PMX; Toray Industries Inc., Tokyo Japan) was developed in Japan in 1994, and it has been used for the treatment of endotoxemia in septic shock. Reduction of the serum levels of several endotoxins following PMX has been recognized.

Methods

We treated 12 patients with severe pneumonia complicated by septic shock by direct hemoperfusion with PMX. The patients were divided into two groups based on the results of analysis of the oxygenation status immediately after DHP-PMX (Group A, increase of the PaO₂/FiO₂ ratio by more than 20% (six cases); Group B, increase of the PaO₂/FiO₂ ratio by 20% or less (six cases)). The serum levels of inflammatory mediators (high mobility group box-1 protein, N-arachidonoylethanolamine, 2-arachidonoyl glycerol, plasminogen activator inhibitor 1 and F2-isoprostane) were measured at four time points; before, immediately after, and 1 and 3 days after the DHP-PMX. During the same period, as compared with cases of septic shock of other causation (n = 26) that were treated by DHP-PMX, the pneumonia cases showed significantly higher SOFA scores (15.2 ± 5.2 vs 9.9 ± 3.6; P = 0.0331) and low survival rates (25% vs 73%; P = 0.0017).

Results

The average patient age was 60.4 years; six of the patients were men and six were women. The average APACHE II score was 32.2 ± 9.9, and the average SOFA score was 15.2 ± 5.2 before DHP-PMX. Three patients survived and nine died. Only the serum levels of F2-isoprostane, a marker of oxidative stress, were significantly increased in Group B (P = 0.0331).

Conclusion

The existence of a relationship between the serum levels of F2-isoprostane and rebellious cases by a poor result of DHP-PMX in severe pneumonia patients became evident. Furthermore, cases of septic shock associated with severe pneumonia showed a more serious general condition, and suggested prediction of a poor outcome. The results suggest that therapy targeted against oxidative stress may be important in cases of septic shock caused by severe pneumonia.