Figure 4.

Boxplot summary of von Willebrand factor (vWF) levels expressed as a percentage of a normal pooled plasma control reference. Median levels of vWF were 368% (range, 116% to 742%) pre-intubation, 312% (range, 40% to 814%) immediately post-intubation, and 359% (range, 91% to 653%) at 12 to 26 hours post-intubation. There was no statistically significant difference among the levels of vWF at the three different time points (p = 0.57). The horizontal line represents the median, the box encompasses the 25^th to 75^th percentile, and error bars encompass the 10^th to 90^th percentile.