There were no critical events in either group : In PRO , mean BP during MRI ( from 52 8 to 58 mmHg ) was significantly less than before anesthesia ( 80 12 mmHg ) , while HR remained relatively constant ( range of 97-103 ) at its baseline of 108 21 , but in DEX , mean BP remained unchanged ( from 76 12 to 78 15 ) during anesthesia compared with before anesthesia ( 79 14 mmHg ) , while HR decreased ( 74 16 to 78 15 ) during anesthesia from its baseline ( 102 17 ) .