Clinical Features and Antimicrobial Resistance of Bacterial Agents of Ventilator-Associated Tracheobronchitis in Hamedan, Iran

Abstract

Objectives: Ventilator-associated tracheobronchitis (VAT) is a common cause of mortality and morbidity in patients admitted to intensive care units (ICUs). This study was conducted to evaluate the clinical course, etiology, and antimicrobial resistance of bacterial agents of VAT in ICUs in Hamedan, Iran. Methods: During a 12-month period, all patients with VAT in a medical and a surgical ICU were included. The criteria for the diagnosis of VAT were fever, mucus production, a positive culture of tracheal secretions, and the absence of lung infiltration. Clinical course, including changes in temperature and tracheal secretions, and outcomes were followed. The endotracheal aspirates were cultured on blood agar and chocolate agar, and antimicrobial susceptibility testing of isolates were performed using the disk diffusion method. Results: Of the 1 070 ICU patients, 69 (6.4%) were diagnosed with VAT. The mean interval between the patient’s intubation and the onset of symptoms was 4.7±8.5 days. The mean duration of response to treatment was 4.9±4.7 days. A total of 23 patients (33.3%) progressed to ventilator-associated pneumonia (VAP), and 38 patients (55.0%) died. The most prevalent bacterial isolates included Acinetobacter baumannii (24.6%), Pseudomonas aeruginosa (20.2%), and Enterobacter(13.0%). P. aeruginosa and Enterobacter were the most prevalent bacteria in surgical ICU, and A. baumannii and K. pneumoniae were the most common in the medical ICU. All A. baumannii and Citrobacter species were multidrug-resistant (MDR). MDR pathogens were more prevalent in medical ICU compared to surgical ICU (p < 0.001). Conclusions: VAT increases the rates of progression to VAP, the need for tracheostomy, and the incidence of mortality in ICUs. Most bacterial agents of VAT are MDR. Preventive policies for VAP, including the use of ventilator care bundle, and appropriate empirical antibiotic therapy for VAT may reduce the incidence of VAP.

Keywords

• Ventilator-Associated Tracheobronchitis
• Antibiotic Resistance
• Nosocomial Infections