Effect of N-acetylcysteine treatment on oxidative stress and inflammation after severe burn.

Oxidative stress and inflammation generate edema in burns. The aim of our study was to assess effect of N-acetylcysteine (NAC) on oxidative stress, inflammation, fluid requirement, multiple organ dysfunction (MOD) score and vasoactive drug requirement. In this study 15 patients were on standard therapy, whereas for other 15 patients NAC was supplemented. Blood samples were taken on admission and on the next five consecutive mornings. Levels of malondialdehyde, protein sulfhydril (PSH) groups, reduced gluthation (GSH), activity of myeloperoxidase, catalase and superoxide dismutase enzymes and induced free radical generating capacity were measured as well as concentrations of TNF-α, IL-6, IL-8, and IL-10. MOD score, use of vasopressor agents and fluid utilisation were recorded daily. NAC treatment increased GSH level on days 4-5 (p<0.05) and PSH level on days 2-6 (p<0.05) compared to controls. Plasma IL-6 was lower on days 4-5 (p<0.05), IL-8 on days 4-6 (p<0.05) and IL-10 on days 4-6 (p<0.05) in NAC group. NAC group received less catecholamines than controls (p<0.01) from day 4 without significant differences in MOD score. NAC treatment is associated with a diminished oxidative stress reflected in preserved antioxidant levels, lower inflammation mirrored in lower interleukin levels and less vasopressor requirement.

Effect of N-acetylcysteine treatment on the expression of leukocyte surface markers after burn injury.

Oxidative stress and inflammatory processes generate edema in burns. Treatment of consequent hypovolemia is a challenge. The aim of study was to assess if glutathione pro-drug N-acetylcysteine (NAC) can influence inflammation and fluid requirement. We also aimed to compare organ functions scores and vasoactive drug requirement. This prospective randomised study involved 28 patients with burn injury affecting more than 20% of body surface area. Fourteen patients were on standard therapy, whereas for other 14 patients NAC was supplemented. Blood samples were taken on admission and on the next five consecutive mornings. Leukocyte surface marker expressions were determined, multiple organ function scores, use of vasopressor agents and fluid requirements were recorded daily. Expression of CD11a (p < 0.05), CD18 (p < 0.05) and CD97 (p < 0.01) on the granulocytes were significantly lower in the NAC treated group, similarly to lymphocyte CD 49d (p < 0.05) and monocyte CD 49d (p < 0.01) and CD 97 (p < 0.05) expression. No significant difference was found in the fluid requirement between groups but patients the NAC group required less vasopressor and inotropic drugs from day 4. NAC treatment is associated with a less pronounced inflammation reflected in lower CD marker expression and vasopressor requirement.

Extravascular lung water index as a sign of developing sepsis in burns.

Sepsis and multiple organ failure remain the leading cause of mortality and morbidity in burns. The aim of our study was to analyse the predictive value of extravascular lung water index (EVLWI) in the development of severe septic complications and mortality. The records of 28 patients with total burned surface area >20% were analysed (EVLWI, procalcitonin (PCT), intrathoracic blood volume index (ITBVI), positive end-expiratory pressure (PEEP), Baltimore Sepsis Scale (BaSS)). Diagnosis of infection (day 0) was based on consensus conference of the American Burn Association. EVLWI correlated with PCT (r=0.597), and PEEP (r=0.501) on day 0 and with BaSS (r=0.524) and MODS (r=0.513) from day 1. EVLWI was elevated (p<0.05) from one day before diagnosis of infection, PCT was higher (p<0.05) from day 0 only. ROC analysis for EVLWI on day -1 and for PCT on day 0 showed similar areas under curve (0.760; 0.766). EVLWI >9 ml kg(-1) on day -1 predicted sepsis (89% sensitivity, 72% specificity). After antibiotic treatment EVLWI remained high in non-survivors, decreased in survivors, whereas PCT decreased in both groups. Our data suggest that EVLWI is an early warning sign of developing infection and its continuous elevation can predict poor prognosis in burns.