Predictive values of serum amyloid A, toll‐like receptor 4, and sTREM‐1 for ventilator‐associated pneumonia in elderly patients undergoing abdominal surgery with tracheal intubation and general anesthesia

Objectives This study aimed to conduct a retrospective study to identify inflammatory biomarkers for predicting ventilator‐associated pneumonia in elderly patients. Methods Our retrospective study included 265 elderly patients (age ≥60 years) undergoing abdominal surgery with tracheal intubation and general anesthesia, with 93 experiencing varying degrees of ventilator‐associated pneumonia during hospitalization, and 172 without. Serum concentrations of serum amyloid A (SAA), toll‐like receptor 4 (TLR4), and soluble myeloid triggering receptor 1 (sTREM‐1) were measured at 24 h post‐operation using enzyme‐linked immunosorbent assay. Comparisons of SAA, TLR4, and sTREM‐1 and other risk factors at 24 h post‐operation between elderly patients with and without ventilator‐associated pneumonia were performed. Results The study revealed a 35.1% incidence of postoperative ventilator‐associated pneumonia among elderly patients. Upregulations of SAA, TLR4, and sTREM‐1 were observed in patients with ventilator‐associated pneumonia. Chronic obstructive pulmonary disease, smoking, and tracheal intubation were identified as independent risk factors. The joint prediction model was demonstrated with superior predictive accuracy (area under the curve = 0.89) compared to individual biomarkers. Correlations with procalcitonin further supported the predictive potential of SAA, TLR4, and sTREM‐1 in an inflammatory response. Conclusions SAA, TLR4, and sTREM‐1, particularly when combined, serve as valuable prognostic indicators for postoperative ventilator‐associated pneumonia in elderly patients undergoing abdominal surgery with tracheal intubation and general anesthesia. The joint prediction model offered a promising tool for early risk assessment.