Among these 300 patients, 126 patients had confirmed VAP, while 174 did not meet the criteria for VAP.<h4>Results</h4>The reference ranges of serum presepsin, PCT, and LBP in patients with confirmed VAP were all higher than those in patients with VAP criteria not fulfilled (<i>p</i> < 0.0001). Here, LBP is linked to ventilator-associated pneumonia.