Resumen

MAZULLO FILHO, João Batista Raposo et al. The effects of mechanical ventilation on oxidative stress. Rev. bras. ter. intensiva [online]. 2012, vol.24, n.1, pp. 23-29. ISSN 0103-507X.  http://dx.doi.org/10.1590/S0103-507X2012000100004.

OBJECTIVE: Mechanical ventilation is a mainstay of therapy in intensive care units; however, its deleterious effects need to be assessed. Therefore, we aimed to assess oxidative stress in patients admitted to an intensive care unit undergoing invasive mechanical ventilation. METHODS: This cross-sectional study included 12 invasive mechanical ventilation patients. Blood samples (3 mL) were collected on the first and last days on invasive mechanical ventilation. Thiobarbituric acid-reacting substances (TBARS) were assessed in plasma, and superoxide dismutase (SOD) and catalase (CAT) were assessed in erythrocytes. RESULTS: The mean age was 64.8 ± 17.6 years, the tidal volume (VT) 382 ± 44.5 mL, and the APACHE II score 15 ± 7. When initial and final TBARS were compared, a significant difference was identified (3.54 ± 0.74 vs. 4.96 ± 1.47, p = 0.04). Antioxidant enzymes showed no significant differences. Correlations between PaO₂/FiO₂ and TBARS (r = 0.4), SOD and PaO₂/FiO₂ (r = 0.51) and APACHE II and SOD (r = 0.56) were identified. Six patients died. CONCLUSION: Patients undergoing invasive mechanical ventilation can develop redox state changes, showing increased TBARS and reduced antioxidant enzymes.

Palabras llave : Oxidative stress; Intensive care units; Respiration, artificial; Thiobarbituric acid reactive substances.