Effects of Polymyxin B-Immobilized Fiber Hemoperfusion on Amino Acid Imbalance in Septic Encephalopathy

Abstract

Background: Septic encephalopathy is a common term denoting the signs of progressing central nervous system dysfunction in septic patients. Metabolic alterations including amino acid imbalance are involved in the pathogenesis of septic encephalopathy. The aim of the present study was to determine whether the ratio of branched-chain amino acids to aromatic amino acids is altered in patients with septic encephalopathy and whether polymyxin B-immobilized fiber (PMX-F) hemoperfusion affects this balance. Methods: 16 septic patients with encephalopathy, 10 septic patients without encephalopathy, and 20 healthy controls were included in this study. Sepsis was diagnosed according to the ACCP/SCCM Consensus Conference criteria. Plasma endotoxin levels, interleukin-6 (IL-6) levels, and amino acid ratios were measured before and after PMX-F treatment. Results: Within 12 h of the onset of septic encephalopathy, plasma endotoxin and IL-6 levels were increased significantly in septic patients with encephalopathy in comparison to those in septic patients without encephalopathy (endotoxin, p < 0.05; IL-6, p < 0.01) and those in healthy controls (endotoxin; p < 0.001; IL-6, p < 0.001). The ratio of branched-chain amino acids to aromatic amino acids in septic patients with encephalopathy was decreased in comparison to the ratio in septic patients without encephalopathy (p < 0.05) and that in healthy controls (p < 0.01). PMX-F treatment reduced plasma endotoxin (p < 0.01) and IL-6 levels (p < 0.01) and increased the ratio of branched-chain amino acids to aromatic amino acids (p < 0.01). Conclusion: The amino acid imbalance in patients with septic encephalopathy may be a marker for the severity of the septic syndrome, and PMX-F hemoperfusion is effective in ameliorating the increased plasma endotoxin and IL-6 levels and the amino acid imbalance in these patients.

Changes of rScO2 and ScvO2 in childrenwith sepsis‑related encephalopathywith different prognoses and clinical features

“…Terborg et al (11) have pointed out that vasomotor dysfunction which was regarded as the main cause of sepsis-associated encephalopathy, often leads to dysregulation of cerebral blood flow and can directly affect brain function and cerebral blood circulation. Studies have shown that patients with sepsis have relatively high levels of aromatic amino acids in plasma, which can easily lead to the production of pseudo-neurotransmitters, affect neuronal function, and cause symptoms and signs of various neurological impairments including disturbance of consciousness (12,13). Sharshar et al (14) performed pathological examination on the brain tissue of patients who died of sepsis and found that the incidence of microabscess was high and microabscess may be one of the causes of sepsis-associated encephalopathy.…”

Changes in Plasma Interleukin-18 by Direct Hemoperfusion with Polymyxin B-Immobilized Fiber in Patients with Septic Shock

“…Hemoperfusion by PMX-F is reported to be safe and effective for sepsis or septic shock and was performed as described previously [6][7][8]13] . PMX is bound by means of its amino group to ␣ -chloracetamidemethyl polystyrene fi bers, and PMX-F consists of a mean 7 mg PMX/1 g fi ber.…”

“…The adsorbent column used clinically is a 170-ml polypropylene tube containing 53 g of PMX-F bound covalently to 370 mg PMX. PMX-F therapy was repeated twice with a 24-hour interval as described previously [7,13] . Access to the circulation for direct hemoperfusion with PMX-F was obtained via a double-lumen catheter (Arrow International Inc., Reading, Pa., USA) inserted into the femoral vein by Seldinger's method.…”

“…Each sample was kept at -80 ° C prior to assay. Blood endotoxin concentrations were determined by the endospecy test [7,13] ; the normal upper limit being 9.8 pg/ml. Plasma IL-18 concentrations were measured by enzymelinked immunosorbent assay (MBL, Nagoya, Japan; intra-and interassay coeffi cients of variation were 5.03 and 6.25%, respectively).…”

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“…PMX-F treatment is indicated for use in patients with sepsis or septic shock caused by Gram-negative bacteria. Because of the high affinity of PMX-F for endotoxin, the rationale underlying extracorporeal therapy would be to remove circulating endotoxin by adsorption, thus preventing progression of the biological cascade of sepsis [10,11]. …”