Mechanical ventilation (MV) can induce lung oxidative stress, which plays an important role in pulmonary injury. This study compared protective conventional mechanical ventilation (CMV) and high-frequency oscillatory ventilation (HFOV) for oxygenation, oxidative stress, inflammatory and histopathological lung injury in a rabbit model of acute lung injury (ALI). Rabbits (n = 30) were ventilated at FiO(2) 1.0. Lung injury was induced by tracheal saline infusion (30 mL/kg, 38°C). Animals were randomly assigned to: (a) sham control (CG: tidal volume [V(T)] 6 mL/kg, positive end expiratory pressure [PEEP] 5 cmH(2)O, respiratory rate [RR] 40 ipm); (b) ALI + CMV (CMVG: V(T) 6 mL/kg, PEEP 10 cmH(2)O, RR 40 ipm); or (c) ALI + HFOV (HFG: mean airway pressure [Paw] 14 cmH(2)O, RR 10 Hz) groups. Lung oxidative stress was assessed by total antioxidant performance assay, inflammatory response by the number of polymorphonuclear leukocytes/bronchoalveolar lavage fluid/lung and pulmonary histological damage was quantified by a score. Ventilatory and hemodynamic parameters were recorded every 30 min. Both ALI groups showed worse oxygenation after lung injury induction. After four hours of ventilation, HFG showed better oxygenation (partial pressure of oxygen [PaO(2)] - CG: 465.9 ± 30.5 = HFG: 399.1 ± 98.2 > CMVG: 232.7 ± 104 mmHg, P < 0.05) and inflammatory responses (CMVG: 4.27 ± 1.50 > HFG: 0.33 ± 0.20 = CG: 0.16 ± 0.15; polymorphonuclear cells/bronchoalveolar lavage fluid/lung, P < 0.05), less histopathological injury score (CMVG: 5 [1-16] > HFG: 1 [0-5] > CG: 0 [0-3]; P < 0.05), and lower lung oxidative stress than CMVG (CG: 59.4 ± 4.52 = HFG: 69.0 ± 4.99 > CMVG: 47.6 ± 2.58% protection/g protein, P < 0.05). This study showed that HFOV had an important protective role in ALI. It improved oxygenation, reduced inflammatory process and histopathological damage, and attenuated oxidative lung injury compared with protective CMV under these experimental conditions considering the study limitations.

BACKGROUND: Conventional mechanical ventilation (CMV) is fundamental in acute respiratory

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OBJECTIVES: To review the literature on the most up-to-date knowledge in pathophysiology, management and prevention of drowning accidents in the pediatric age group to propose a protocol for the care of these patients in the emergency department. METHODS: Systematic literature review in PubMed, Embase and Cochrane Library databases using drowning, pediatrics, emergency treatment and accident prevention descriptors, including articles published in the last 5 years that cover the objectives of the present study. RESULTS: Worst drowning outcomes are associated with age < 5 years, submersion time > 5 minutes, higher Szpilman score, and admission with lower Glasgow Coma Scale, hypothermia < 30°C, acidosis, hyperglycemia, hypernatremia, hyperkalemia, elevation of lactate and liver enzymes and an abnormal chest X-ray. CONCLUSIONS: The analysis of prognostic factors through a review of the current literature provided the development of an algorithm for managing drowning patients in pediatric emergency and reinforced the importance of working preventive measures collectively.