Table 2.
Redox characteristics of plasma in adults with sepsis
| Patient groups | Method | Reference | ||
|---|---|---|---|---|
| Anti-oxidant | ||||
| Ascorbate (mg/L) | Control: 1.71 ± 0.46 | Sepsis: 0.55 ± 0.28 | Spectrophotometric assay | [116] |
| Control: 4.5 to 12 | Critically injured: 1.1 ± 0.3 | HPLC | [117] | |
| Retinol (μg/L) | Control: 735 ± 183 | Septic shock: 265 ± 193 | HPLC | [118] |
| Tocopherol (mg/L) | Control: 11.5 ± 1.3 | Septic shock: 3.6 ± 2.0 | HPLC | [118] |
| β-Carotene (μg/L) | Control: 619 ± 259 | Septic shock: <101 | HPLC | [118] |
| Lycopene (μg/L) | Control: 522 ± 184 | Septic shock: <154 | HPLC | [118] |
| Oxidative stress biomarkers | ||||
| Total plasma thiols (R-SH) (μmol/L) | Control: 364 ± 22 | Sepsis: 138 ± 14 | Ellman's method | [119] |
| Lipid peroxidation (μmol/L) | Control: <2 | Patients with >3 failing organs: 4.9 ± 2.3 | TBARS assay | [118] |
| Control: 0.92 ± 0.39 | Sepsis survivors: 0.99 ± 0.14 | TBARS assay | [120] | |
| Sepsis non-survivors: 3.33 ± 2.29 | ||||
| Lipid peroxidation (nmol/mg of protein) | Sepsis (day 1): 2.4 | Sepsis (day 7): 2.9 | FOX assay | [121] |
| Total anti-oxidant capacity (nmol/mg of protein)a | Sepsis (day 1): 1.5 | Sepsis (day 7): 1.1 | ABTS assay | [121] |
| Total anti-oxidant capacity (%) | Control: 57.3 to 60.3 | Survivors: 51.4 to 55.4 | ABTS assay | [30] |
| Non-survivors: 46.1 to 47.6 | ||||
| Total anti-oxidant capacity (μmol/L) | Control: 354 ± 9 | Sepsis: 265 ± 32 | TRAP assay | [31] |
| Septic shock: 452 ± 34 |
aThe use of total anti-oxidant capacity assays is associated with some pitfalls; therefore, the results obtained with such methods should be taken with some caution. For example, urate interferes with both the ABTS and the TRAP assays, potentially leading to falsely high values [23]. Urate increases in many pathophysiological conditions, for example, in renal failure, which may develop in sepsis. Another problem is that plasma contains a complex mixture of anti-oxidants that react at different rates, so some of them may not be detected by rapid assays [23]. ABTS, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid); FOX, ferrous oxidation-xylenol orange; HPLC, high-performance liquid chromatography; TBARS, thiobarbituric acid reactive substances; TRAP, total radical-trapping antioxidant potential.