The effects of plasmapheresis on hemodynamic parameters and tissue oxygenations in septic patients

The hemodynamic pattern of sepsis characterized by a high cardiac index associated with low systemic vascular resistances and alterations on tissue oxygenation is caused by the release of mediators during the host-infecting microorganism interaction. We thought that removing those endotoxins and inflammatory mediators by plasmapheresis would improve hemodynamic changes and tissue oxygenation.

After ethical approval for the trial was obtained, patients were prepared for plasmapheresis. The criteria for entry to the trial were sepsis as described by Bone and colleagues [1]. The severity of illness and mortality rates was classified and calculated using the APACHE II scale, MODS and SOFA. After obtaining the laboratory data and calculating the scores, hemodynamic assessment and tissue oxygenation calculations were performed using the thermodilution technique just before the first plasmapheresis. Plasmapheresis was performed twice substituting with fresh frozen plasma as a 1:1 ratio for the calculated plasma volume. The second plasmapheresis was performed after 48 hours. Hemodynamic assessment and tissue oxygenation calculations were repeated before the second plasmapheresis and at the end of the procedure (72 hours). The outcomes at 28 days were recorded. Statistical analysis was performed with SPSS version 11.0 for Windows (Chicago, IL, USA), values are expressed as mean ± SD and P < 0.05 considered statistically significant.

We studied 10 patients treated in the ICU with plasmapheresis. The difference between the calculated mortality rate based on initial APACHE II scores (52 ± 22.1), and 28-day mortality of all patients (20%), was significant (P < 0.05). The enhancement of APACHE II (from 19.9 ± 6.6 to 12.6 ± 8.5), MODS (from 8.6 ± 3.6 to 5.2 ± 3.4), and SOFA (from 9.1 ± 2.4 to 5.5 ± 4.3) scores between the baseline and the end of the procedure was statistically significant (P < 0.01). The changes in hemodynamic parameters were not significant (Table 1). Despite the improvements in oxygen delivery, oxygen consumption and oxygen extraction ratio being not significant before the first plasmapheresis, the decrease in plasma lactate level (48.2 ± 29.3) was statistically significant at the end of the procedure (20.7 ± 16.2) (P < 0.007), and correlated with the 28-day mortality. The change in plasma C-reactive protein from 124.5 ± 43.2 to 36.9 ± 20.4 was also significant (P < 0.05).

Table 1

As the sepsis is described as 'malign intravascular inflammatory' caused by mediators, the hypothesis is that removing those mediators will improve the therapeutic efforts. We thought that in the early stages of sepsis, plasmapheresis may be considered a therapeutic method even during progressive sepsis that is complicated with disseminated intravascular coagulation.