α-Amylase concentrations measured in the tracheal aspirates of standard-cuff and tapered-cuff patients. (A and B) Percentages of patients whose α-amylase levels were greater than 1,685 μg/ml at admission (day 1) and 24 h later (day 2), respectively. (C and D) Box plots of α-amylase levels on days 1 and 2, respectively: internal horizontal lines are the medians, lower and upper box limits are the 25 to 75% interquartile range, respectively, T-bars represent the ranges, and • are outliers.