[RESULTS] Horses of group K required significantly higher concentrations of isoflurane ( group A : 1.08 0.1 % ; group K : 1.34 0.2 % ) and had an overall lower MAP ( group A : 88.4 10.3 mmHg ; group K : 76.6 11.6 mmHg ) and CO ( group A : 36.9 11.7 l/min ; group K : 28.5 7.2 l/min ) but needed significantly more dobutamine ( group A : 0.37 0.17 g/kg/min ; group K : 0.99 0.46 g/kg/min ) compared to group A. Complete relaxation occurred 9.5 2.5 minutes after atracurium bolus and lasted for 25 7.1 minutes .