The pony as a model for septic shock.

This study was conducted to determine the feasibility of using alert, conscious ponies as a model for septic shock in man. Ten ponies were given 0.7-5 X 10(9) organisms/kg of body weight of live E coli intravenously over one hour. All ponies died and exhibited signs of low cardiac output septic shock. significant decreases were found in cardiac index to 3.15 +/- 0.1 liters/min/m2 (P less than 0.05), white blood cell count to 1,930 +/- 100 cells/m3 (P less than 0.05), preterminal blood glucose to 75 +/- 5 mg/dl (P less than 0.05), PaO2 to 75.7 +/- 5.7 mm Hg (P less than 0.05), and pH to 7.15 +/- 0.5 (P less than 0.05). Increases were noted in systemic resistance to 3,869 +/- 322 dynes/dic/cm-5 (P less than 0.05), pulmonary resistance to 770.8 +/- 11.12 dynes/sec/cm-5 (P less than 0.05), pulmonary arterial pressure to 41 +/- 7 mm Hg (P less than 0.05), pulmonary wedge pressure to 19.5 +/- 2.5 mm Hg (P less than 0.05), intrapulmonary shunt to 16.43 +/- l.73% (P less than 0.05), early blood glucose to 204 +/- 9.0 mg/dl (P less than 0.05), and excess lactate concentration to 53.06 +/- 5.3 mg/dl (P less than 0.05). From these data it appears that the septic pony shows changes similar to low output septic shock documented in man.