Intravenous anti- IgY-antibodies do not decrease pulmonary bacterial concentrations in a porcine model of ventilator-associated pneumonia

Abstract

Ventilator associated pneumonia (VAP) caused by P. aeruginosa is a cause of morbidity and mortality in critically ill patients. The spread of pathogens with anti-microbial resistance mandates the investigation of novel therapies. Specific polyclonal anti- P. aeruginosa IgY-antibodies ( Pa- IgY) might be effective for VAP caused by P. aeruginosa. The objective of this study was to investigate if intravenous Pa- IgY decreases the lower airway concentration of P. aeruginosa in VAP. We used a double blind randomized placebo controlled porcine model of VAP caused by P. aeruginosa . Eighteen pigs were randomized to either receive intravenous Pa- IgY or placebo. Repeated registration of physiological parameters and sampling was performed for 27 h. Concentration of P. aeruginosa in BAL-cultures was similar in both groups with 10 4.97 ± 10 2.09 CFU/mL in the intervention group vs 10 4.37 ± 10 2.62 CFU/mL in the control group at the end of the experiment. The intervention group had higher heart rate, cardiac index, oxygen delivery and arterial oxygen tension/fraction of inspired oxygen-ratio, but lower plasma lactate and blood hemoglobin levels than the control group. In summary, in an anesthetized and mechanically ventilated porcine model of VAP, Pa- IgY at the dose used did not decrease concentrations of P. aeruginosa in the lower airways.