Effects of glucocorticoids in ventilated piglets with severe pneumonia

There is clinical evidence suggesting that glucocorticolds may be useful in severe pneumonia, but the pathogenic mechanisms explaining these beneficial effects are unknown. The aim of the present study was to determine the effects of adding glucocorticoids to antibiotic treatment in an experimental model of severe pneumonia. In total, 15 Lagerwhite-Landrace piglets were ventilated for 96 h. After intubation, a 75 mL solution containing Pseudomonas aeruginosa (106 cfu center dot mL(-1)) was bronchoscopically inoculated. The animals were randomised into three groups 12 h after inoculation: 1) untreated; 2) treated with ciprofloxacin; and 3) treated with ciprofloxacin plus methylprednisolone. Physiological and laboratory parameters were monitored throughout the study. Pro-inflammatory cytokines were measured in serum and bronchoalveolar lavage (BAL). Histopathology of the lungs and cultures from blood, BAL and lungs were performed. At the end of the study, piglets receiving the antibiotic plus glucocorticoids showed: 1) a decrease in the concentration of interieukin-6 in BAL; and 2) a decrease in the global bacterial burden both in BAL and lung tissue. In conclusion, in this experimental model of pneumonia, the association of glucocorticolds with antibiotics attenuates local inflammatory response and decreases bacterial burden in the lung.