Enrique Serrano

Oxidative stress in critically ill patients with systemic inflammatory response syndrome

ObjectiveTo evaluate whether critically ill patients with systemic inflammatory response syndrome, on admission to an intensive care unit, had more severe oxidative stress than those without this syndrome. DesignA prospective, cohort study. SettingA mixed medical and surgical adult intensive care unit with 12 beds. PatientsA total of 68 consecutive patients admitted to the intensive care unit. InterventionsVenous blood samples were routinely obtained within 24 hrs of admission. Measurements and Main ResultsPatients’ plasma total antioxidant capacity, the lipid peroxidation products malondialdehyde and 4-hydroxynonenal, reduced sulfhydryl groups, and nitrites/nitrates were measured by spectrophotometric technique at admission to the intensive care unit. Myeloperoxidase (enzyme-linked immunosorbent assay) and polymorphonuclear elastase (immuno-activation assay) were also measured on admission to the intensive care unit. The patients with criteria of systemic inflammatory response syndrome (n = 20) had higher Acute Physiology and Chronic health Evaluation III scores (determined by collecting the worst value within 24 hrs after admission to the intensive care unit) and plasma concentrations of lipid peroxidation products and nitrites/nitrates and lower plasma concentration of reduced sulfhydryl groups and plasma total antioxidant capacity than patients without the syndrome (n = 48). Moreover, the markers for leukocyte activation, myeloperoxidase and polymorphonuclear elastase, presented higher concentrations in the plasma of patients with systemic inflammatory response syndrome. ConclusionsPatients admitted to the intensive care unit with criteria of systemic inflammatory response syndrome had a more severe oxidative stress than patients without this syndrome.

Plasma redox status relates to severity in critically ill patients

Objective To determine the relation between plasma redox status and severity of illness for patients admitted to an intensive care unit (ICU). Design A prospective cohort study. Setting A mixed medical and surgical adult ICU with 12 beds. Patients A total of 73 consecutive patients admitted to the ICU. Interventions Venous blood samples were routinely obtained within 24 hrs of admission. Measurements and Main Results Plasma total antioxidant capacity and lipoperoxides were measured by spectrophotometric technique at admission to the ICU. The plasma ratio total antioxidant capacity (mM)/lipoperoxides (&mgr;M) was used as an index of plasma redox status. Plasma concentration of the markers of leukocyte activation myeloperoxidase (enzyme-linked immunosorbent assay) and polymorphonuclear-elastase (immunoactivation assay) were also measured at admission to the ICU. Analysis of correlation between plasma ratio total antioxidant capacity/lipoperoxides and APACHE III score showed a negative association (p < .001, Spearman correlation test). Myeloperoxidase and polymorphonuclear-elastase correlated positively with Acute Physiology and Chronic Health Evaluation III scores (r2 = 0.58;p < .001; and r2 = 0.05;p = .035; respectively). Conclusions Plasma redox status relates to severity in critically ill patients. We propose that it would be reasonable to provide antioxidant therapy as part of routine management of patients admitted to a mixed ICU, regardless of the specific reason for ICU admission. Plasma redox status might become useful to evaluate the risk in critically ill patients.

Hormone replacement therapy for oxidative stress in postmenopausal women with hot flushes

Objective To assess the association of hot flushes during postmenopause with oxidative stress and to determine whether hormone replacement therapy (HRT) affects the plasma redox status of postmenopausal women. Methods We conducted a prospective clinical study of 49 postmenopausal women who have (n = 29) or do not have (n = 20) hot flushes. Twelve of the postmenopausal women with hot flushes and six without were treated with HRT (estradiol patches and medroxyprogesterone acetate) for 4 months. Plasma level of estradiol, total antioxidant status, reduced sulfhydryl groups, lipoperoxides, total cholesterol, and triglycerides were measured at 4-month intervals in both groups, before and after treatment. Results Postmenopausal women who have hot flushes, had lower total basal antioxidant status in plasma (.9 ± .01 compared with 1.14 ± .01 mmol/L), lower concentration of reduced sulfhydryl groups (145 ± 4 compared with 200 ± 3 μmol/L), and higher concentration of lipoperoxides (2.88 ± .04 compared with 2.61 ± .04 μmol/L) than women without hot flushes. After HRT, total antioxidant status and reduced sulfhydryl groups increased, and lipoperoxides decreased similarly in both groups. Hormone replacement therapy decreased the frequency of hot flushes per day from 11.2 ± 0.8 to 1.4 ± 0.3. Conclusion Hot flushes in postmenopausal women were associated with the oxidative process. Hormone replacement therapy decreases oxidative stress and the number of episodes of hot flushes. Because oxidative stress is associated with a high risk for cardiovascular diseases, HRT might protect women with hot flushes.