To study the prevalence, risk factors and outcomes of nosocomial tracheobronchitis (NTB), a prospective observational cohort study was conducted in patients on mechanical ventilation (IVL) for more than 48 hours. Only the first episodes of NTB were analyzed. Patients with nosocomial pneumonia, which was not preceded by nosocomial tracheobronchitis, were not included in the study.

The study lasted 6.5 years. Over the entire period, the development of nosocomial tracheobronchitis was recorded in 201 (10.6%) patients out of 1889 people meeting the inclusion criteria. In patients with therapeutic pathology, NTB developed on average over 11.8 ± 7.2 days of mechanical ventilation, in patients with surgical pathology - over 13.1 ± 9.3 days.

The use of antibiotics during the hospital stay was an important risk factor for the development of nosocomial tracheobronchitis (patients with surgical pathology: OS = 5.02; p less than 0.001; patients with therapeutic pathology: OS = 1.89; p less than 0.001)

NTB developed more often in patients with surgical pathology than in patients with therapeutic pathology (15.3% vs 9.9%, respectively, OS = 1.64; p = 0.01). The risk factors for the development of NTB in patients with therapeutic pathology were the age of more than 60 years (OS = 1.80; p = 0.001), the presence of COPD (OS = 1.57; p = 0.007 ) and the appointment of antimicrobials in the 2 weeks before ICU admission (OR = 1.52; p = 0.007).

The most common causative agents of NTB in patients with surgical and therapeutic pathology were Pseudomonas aeruginosa (31.8% and 28%, respectively), Staphylococcus aureus (20 , 4% and 17.8%, respectively) and Acinetobacter baumannii (13.6 and 26.5%, respectively).

There was no statistically significant difference between the incidence of nosocomial pneumonia in patients with previous NTB and in patients without previous NTB, as well as in patients who received antibiotics compared to those who did have not received any. At the same time, mortality was significantly lower in the group of patients with therapeutic pathology who received antibiotics.

The development of NTB has led to a significant increase in the length of stay in ICU and the duration of mechanical ventilation, even if the patients did not develop nosocomial pneumonia afterwards.

The results of this study show that NTB is common in ICU patients. Additional studies are needed to assess the effect of antibiotic therapy on NTB outcomes.