To investigate the disease characteristics and prognosis of elderly patients with ventilator-associated pneumonia (VAP) in the intensive care unit (ICU).

A total of 110 elderly VAP patients admitted to the ICU of Ruijin Hospital, Shanghai Jiaotong University School of Medicine from March 2024 to June 2025 were selected as the VAP group, and 110 age-matched patients without VAP admitted to ICU during the same period were included in the control group. General demographic data, sputum culture bacteriological findings, drug sensitivity test results of main pathogenic bacteria, laboratory data, and ICU monitoring results were collected for both groups. Weaning success, weaning failure requiring tracheotomy long-term mechanical ventilation, and mortality were recorded for both groups. Binary logistic regression models were used to analyze the risk factors affecting the incidence of VAP and its later deaths in elderly patients with mechanical ventilation. SPSS 26.0 was used for statistical analysis. Data comparison between two groups was performed using t test or ${\chi }^2$ test depending on data type.

Using VAP occurrence as the dependent variable (0=no, 1=yes), binary logistic multivariate analysis indicated that underlying pulmonary comordities (OR=3.086, 95%CI 1.807–5.270), albumin < 30 g/L (OR=3.209, 95%CI 2.025–5.087), mechanical ventilation duration > 5 d (OR=5.191, 95%CI 2.735–9.854), acute physiology and chronic health evaluation (APACHE) Ⅱ score > 15 points (OR=5.888, 95%CI 2.611–13.282), re-intubation (OR=2.092, 95%CI 1.338–3.270), and mental coma (OR=2.401, 95%CI 1.697–3.397) were independent risk factors for VAP in elderly ICU patients with mechanical ventilation. In total, 136 pathogenic strains were cultured from VAP 110 patients, including 107 Gram-negative strains (78.68%), 23 Gram-positive strains (16.91%), and 6 fungi (4.41%). The most common pathogens were Acinetobacter baumannii (37 strains, 27.21%), Pseudomonas aeruginosa (23 strains, 16.91%), Klebsiella pneumoniae (16 strains, 11.76%), and Staphylococcus aureus (12 strains, 8.82%). The average weaning duration in the VAP group was longer than that in the control group. The weaning success rate in the VAP group (46.36%, 51/110) was significantly lower than that in the control group (85.45%. 94/110). The proportion of weaning failure requiring tracheotomy long-term mechanical ventilation (12.73%, 14/110) and mortality (40.91%, 45/110) in the VAP group were significantly higher than those (3.65%, 4/110; 12.00%, 12/110) in the control group (P<0.05). Using the prognosis of VAP patients as the dependent variable (survival=0, death=1), binary logistic multivariate regression analysis identified age ≥ 80 years (OR=5.635, 95%CI 2.980–10.655), albumin level < 30 g/L (OR=2.370, 95%CI 1.592–3.529), mechanical ventilation duration > 15 d (OR=3.310, 95%CI 1.465–7.481), APACHE Ⅱ score > 15 points (OR=1.941, 95%CI 1.191–3.161), and multidrug-resistant organism infection (OR=1.831, 95%CI 1.297–2.586) as independent risk factors affecting the prognosis of VAP patients (all P<0.05).

The later death rate and weaning failure rate of elderly ICU patients receiving mechanical ventilation with VAP are significantly higher than those without VAP. It is suggested that the patients with high-risk VAP and death risk should be effectively screened according to the results of the study in clinical practice. At the same time, the results of pathogen and drug sensitivity test should be used as reference to rationally apply antibiotics to reduce the risk of VAP and later deaths.