Within each age group , there were 3 escalating dose levels , including a loading dose ( LD , g/kg ) followed by a maintenance dose ( MD , g kg ( -1 ) h ( -1 ) ) for 6-24 hours : level 1 , 0.05 LD/MD ; level 2 , 0.1 LD/MD ; and level 3 , 0.2 LD/MD .