Figure 1. Kaplan-Meier survival curve for the 96-hour sepsis study.

The survival comparison in canines receiving haptoglobin or no haptoglobin with (A) or without (B) RBC exchange transfusion after S. aureus challenge. P values are denoted by asterisks indicating significance in comparison between each panel group using stratified log rank tests. (C and D) Mean shock scores (± SEM) at serial time points. The shock score accounts for the level of vasopressor support (norepinephrine) needed to maintain the mean arterial pressure at a preset normal level for canines (mean 80 mmHg). Shock score is compared over 96 hours in canines receiving haptoglobin or no haptoglobin with (C) or without (D) RBC exchange transfusion. Changes from baseline are shown for each study group plotted from a common origin the mean value for animals at baseline. P values indicate significance in each group comparison in each panel and are denoted by asterisks (for changes over time) or crosses (comparing haptoglobin vs. no haptoglobin at each time point). (E and F) Mean (± SEM) lung injury scores (LIS) at serial time points. The LIS detects pulmonary damage via measurements in mean pulmonary artery pressure, alveolar-arterial oxygen gradient, plateau pressure, oxygen saturation, and respiratory rate. The LIS is plotted over time (x axis) for animals receiving haptoglobin or no haptoglobin with (E) or without (F) RBC exchange transfusion. Changes from baseline are shown for each study group plotted from a common origin, with the mean value for animals at baseline. P values indicate significance in each group comparison in each panel and are denoted by asterisks (for changes over time) or crosses (comparing haptoglobin vs. no haptoglobin at each time point). Comparisons of all variables (except survival) were made based on contrasts in linear mixed models, which allow us to account for repeated measurements of each animal and the actual pairing of animals within each cycle.