The primary endpoint was the percentage of patients meeting criteria for ETI , including either one or more major criteria ( respiratory arrest , respiratory pauses with unconsciousness , severe hemodynamic instability , intolerance ) or at least two minor criteria ( reduction of at least @ % of basal PaO@/FiO@ ratio , increase of @ % of PaCO@ , worsening of alertness , respiratory distress , SpO@ less than @ % , exhaustion ) .