To investigate the etiological characteristics and risk factors of hospital acquired pneumonia (HAP) in respiratory intensive care unit (RICU).

One hundred and sixty patients admitted to the RICU of Second Affiliated Hospital of Anhui Medical University from March 2018 to August 2021, and 54 patients complicated with HAP were selected. The pathogenic bacteria of HAP were isolated and identified using the microbial identification system. The paper method was used to test drug sensitivity. Univariate analysis was used to identify the influencing factors of HAP. Multivariate Logistic regression was used to identify the independent risk factors for HAP.

Among the 54 HAP patients, 81 strains of pathogenic bacteria were isolated, including 62 Gram-negative bacteria, 6 Gram-positive bacteria, and 13 fungi. The drug resistance rates of Klebsiella pneumoniae to ceftazidime (85.19%) and cefazolin (77.78%) were high. Pseudomonas aeruginosa had high resistance rates to ceftazidime (94.74%) and cefoperazone/sulbactam (78.95%). Univariate analysis showed that there were no significant differences in gender, body mass index, smoking history, or hypertension history between the HAP group and non-HAP group (P＞0.05), but there were statistically significant differences in age, diabetes history, mechanical ventilation time, oral cleanliness, albumin level, pulmonary disease, hospital stay, and broad-spectrum antibiotic application between the two groups (P＜0.05). Multivariate Logistic regression analysis showed that age＞70 years, mechanical ventilation time＞7 d, history of diabetes mellitus, oral cleanliness, albumin＜30 g/L, pulmonary disease, length of hospital stay, and broad-spectrum antibiotic use were the independent risk factors for HAP among RICU patients.

Gram-negative bacteria are the main pathogenic bacteria of HAP among RICU patients. Age, mechanical ventilation time, diabetes history, oral cleanliness, albumin level, pulmonary disease, hospital stay, and broad-spectrum antibiotic use are the independent risk factors for HAP among RICU patients.