Effects of the beta-2 receptor agonist terbutaline on hemodynamics and gas-exchange in endotoxin shock

The effects of the beta-2 receptor agonist, terbutaline, on hemodynamics and gas-exchange were evaluated in sheep exposed to endotoxin shock. Terbutaline was not given until signs of shock and lung injury had developed. Twenty sheep were anesthetized and ventilated without PEEP. After 90 min of stabilization (t = 0) all animals received E. coli endotoxin 10 micrograms/kg by i.v. infusion during 15 min. Thirty minutes later (t = 30) 10 animals (group TER) received i.v. infusion of terbutaline, 20 micrograms/kg/h, during 4 hours, while the other 10 served as controls (group S). The endotoxin infusion resulted in marked increase in pulmonary artery pressure (PAP) and a significant decrease in mean arterial pressure (MAP), respiratory compliance, arterial oxygen tension (PaO2) and oxygen delivery index (DO2) in both groups (t = 15 and t = 30). After 4 hours the PAP had decreased significantly in the terbutaline treated animals, but remained high in the controls (p less than 0.01). Also, MAP, PaO2, DO2 and compliance improved significantly in the terbutaline treated animals. The wet to dry weight ratio of the lungs was 4.85 +/- 0.2 in the terbutaline treated and 5.35 +/- 0.5 in the controls (p less than 0.05). It was concluded that terbutaline treatment improves gas-exchange and hemodynamics in sheep exposed to endotoxin shock.