When OPLS-DA (R2Y = 0.63, Q2Y = 0.47, p < 0.01) was used to analyze 105 lipids, the most discriminant lipids were VLDL-4 and 5 free and total cholesterol, triglycerides within HDL-2, HDL-3, LDL-1 and HDL and intermediate density lipoprotein total and free cholesterol, apolipoprotein-B, and phospholipid in those with VAP and HDL-4 total cholesterol, and HDL and HDL-4 free cholesterol in those with brain injuries. Here, APOB is linked to ventilator-associated pneumonia.