F2 and infection: In laboratory investigations, only differences in prothrombin time (medians, 13 (IQR 2–17) vs. 18 (IQR 14–23); p = 0.01) and in levels of serum lactate (medians, 2.0 (1.1–2.3) vs. 3.4 (IQR 2.2–5.9); p = 0.03) were observed between lipid A variant infections and infections with wild-type strains (Table 4).