Role of platelet-activating factor antagonism in haemorrhagic shock in pigs

This study aimed at evaluating the role of platelet-activating factor (PAF) antagonism in haemorrhagic shock in juvenile pigs. The animals were bled to a mean arterial pressure of 30 mm Hg which was maintained for 30 min, then they were resuscitated using normal saline 50 ml/kg. Seven pigs received BB-882 (a potent novel PAF antagonist) 1 mg/kg as bolus during resuscitation followed by continuous infusion of 1 mg/kg/h. Seven pigs received only vehicle. The group treated with BB-882 had significantly higher central venous pressure, mean pulmonary artery pressure and pulmonary capillary wedge pressure. The mean arterial pressure and cardiac output were similar in the two groups, while the systemic vascular resistance was significantly reduced by the drug. The BB-882 group had significantly more tachycardia and less arterial pH. Oxygen delivery and consumption and lactic acidaemia were similar in the two groups. These effects were not attributed to anaerobic metabolism and may indicate that PAF antagonism protected against ischaemia and improved the microcirculation in the haemorrhagic shock in pigs.