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

Fariba Lahoorpour,Abdorrahim Afkhamzadeh,Ali Delpisheh

doi:10.12669/pjms.295.3375

Abstract

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). 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). 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.

Highlights

Ventilator-associated pneumonia (VAP) occurs almost 48 hours after the initiation of endotracheal intubation and mechanical ventilation (MV).[1]
VAP is associated with considerable morbidity, including prolonged intensive care unit (ICU) hospitalization, extended mechanical ventilation and increased costs of hospitalization.[4]
Definitions: Pneumonia was considered ventilator associated when its onset occurred after 48 hours of mechanical ventilation and it was diagnosed when new, persistent pulmonary infiltrates appeared on chest radiographs along with at least two of following criteria: fever of ≥ 38°C, leukocytosis of 10,000\ mm[3] or more, and purulent respiratory secretions

Summary

Introduction

Ventilator-associated pneumonia (VAP) occurs almost 48 hours after the initiation of endotracheal intubation and mechanical ventilation (MV).[1] The incidence of VAP varies from 9% to 60% of patients, based on the definition, type of hospital or ICU, study population and levels of antibiotic exposure. VAP is the main cause of nosocomial and acquired infections in ICUs.[2] Many predisposing factors including age and severity of the underlying diseases are associated with developing VAP. History of antibiotic exposure and duration of mechanical ventilation are involved.[3] VAP is associated with considerable morbidity, including prolonged ICU hospitalization, extended mechanical ventilation and increased costs of hospitalization.[4] Risk of VAP will be significantly increased up to 1-3% in intubated patients for each day requirement for mechanical ventilation.[5,6]

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Results

Conclusion