Fig. 4. Time (min) at which intubation was attempted in part II is plotted for each infant ( open symbols ) and child ( closed symbols ). If intubating conditions were good ( circles ) or excellent ( triangles ), time of attempted intubation for the next patient was decreased 0.5 min. If intubating conditions were poor ( inverted triangles ), time of attempted intubation for the next patient was increased 0.5 min.