To investigate the clinical and pathogenic characteristics of ventilator-associated pneumonia (VAP) after severe stroke.

Total of 121 mechanically ventilated patients with severe stroke admitted to the intensive care unit of Shanghai Putuo District Central Hospital from January 2018 to January 2023 were divided into VAP group (53 cases) and non-VAP group (68 cases) according to whether complicated with VAP. The clinical characteristics and risk factors of VAP, incidence of VAP at different mechanical ventilation times, and etiological distribution and drug susceptibility characteristics of VAP were analyzed. Measurement data were measured by independent sample t-test or U test and count data were compared by Pearson Chi-square test or Fisher’s exact probability. The risk factors associated with VAP were analyzed by Univariate analysis and multivariate binary Logistic regression analysis.

There were 53 VAP cases in 121 mechanically ventilated patients, and the incidence rate was 43.8% (53/121). The gender, stroke types, the way of endotracheal intubation, rate of gastric tube retention and complications between VAP and non-VAP groups were without significant differences (all P > 0.05), but age, stroke severity, mechanical ventilation duration, length of hospitalization, medical cost, good prognosis and hospital mortality between the two groups were with significant differences (all P < 0.05). Multivariate Logistic regression analysis showed that age (OR = 2.092, 95%CI: 1.507-2.905, P < 0.001) and Glasgow Coma Scale score (OR = 0.248, 95%CI: 0.103-0.599, P = 0.002) were both independent risk factors for VAP. The incidence of VAP was 28.3% (17/60) among patients for 1-7 d, and the incidence of VAP among patients for 8-14 d was 49.0% (24/49), with significant difference (χ² = 4.900, P = 0.027). Compared with patients with mechanical ventilation for 8-14 d (49.0%, 24/49), the incidence of VAP among patients with mechanical ventilation over 14 d was 100% (12/12), with significant difference (P = 0.001). The pathogen distribution of VAP: total of 95 strains of pathogenic bacteria were isolated from the sputum of 53 patients with VAP, including 75.8% (72/95) of Gram-negative bacteria, 16.8% (16/95) of Gram-positive cocci, and 7.4% (7/95) of fungi. Acinetobacter baumannii accounted for the highest proportion of Gram-negative bacteria up to 34.7% (25/72). Gram-positive bacteria were mainly Staphylococcus aureus [56.3 (9/16)]. The drug susceptibility test results showed that the phenomenon of VAP drug-resistance was severe, with Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli being the four most important Gram-negative resistant bacteria, only sensitive to polymyxin, tigecycline and meropenem. Staphylococcus aureus was the leading Gram-positive resistant bacteria [9 (56.3%)], with extensive resistance to many other antibiotics, except for the low resistance rate to vancomycin [1 (11.1%)], linezolid [1 (11.1%)] and teicoplanin [1 (11.1%)].

Patients with severe stroke had a high incidence of VAP, and age and stroke severity were independent risk factors for VAP, and Acinetobacter baumannii and Staphylococcus aureus were the Gram-negative and positive strains with the highest resistance rate, respectively. VAP has serious adverse effects on stroke prognosis, and aggressive measures are needed to reduce the occurrence of VAP.