Risk factors for acquisition of ventilator-associated pneumonia in adult intensive care units

OBJECTIVE Ventilator Associated Pneumonia (VAP) has an imperative place amongst nosocomial infections leading to increase morbidity and mortality rates. The present study aimed to determine risk factors for acquisition of ventilator- associated pneumonia in an intensive care unit (ICU). METHODS A nested case-control study was carried out from September 2007 to June 2008. All 183 patients hospitalized at the adult ICU ward in Be'sat Hospital, Sanandaj city western Iran over a 48 hour period were included. Bacteriologic diagnosis and antibiotic susceptibility patterns were performed based on Edward & Ewing's methods and CLSI system guidelines. Results : Of the 149 samples which were taken from endotracheal tubes of 183 patients, 48 cases were diagnosed for VAP with an incidence rate of 26.2%. Mean duration of hospitalization was 23.4±10.2 days. The maximum and minimum antibiotic resistance for the gram negative bacteria was 93.3% for Cefalotin and 50% for Amikacin. The main risk factors for acquisition of ventilator- associated pneumonia were mechanical ventilation (Adjusted OR: 1.55, 95% CI: 1.37-1.74), history of antibiotic consumption (AOR: 8.92, CI: 1.16- 66.66) and fever (AOR: 3.11, CI: 1.22- 7.93). CONCLUSIONS VAP is significantly related to ICU hospitalization, mechanical ventilation and history of antibiotics consumption. Cefalotin and Amikacin showed the highest and lowest antibiotic resistance against gram negative bacteria respectively.