Nosocomial Pneumonia in a Pediatric Intensive Care Unit

Background: Nosocomial pneumonia (NP) is the second most common hospital acquired infection. Understanding the pattern of occurrence, risk factors and etiological agents of NP in a PICU, is essential for developing effective infection control measures. This prospective observational study was conducted in a PICU of a tertiary care teaching hospital, to determine the incidence, etiology and risk factors for NP.

Materials And Methods: Patients admitted to the PICU, over a period of 1 year who had endotracheal (ET) intubation, were enrolled consecutively into the study. Demographic details were recorded at the time of inclusion. Diagnosis of NP was based on CDC criteria (1988). Semiquantiative assay of endotracheal aspirate (ETA) with a colony count of > 10(5) cfu/mL was taken as evidence of infection. Colonisation was defined as isolation of organism with <10(5) cfu/mL. Age, nutritional status, number and duration of intubations, duration of mechanical ventilation, sedation, nasogastric feeding were the risk factors studied for development of NP. Intubation attempts of more than one were defined as reintubation. Risk factors found significant on univariate analysis, were subjected to multiple regression analysis to determine the most important predictors of NP.

Results: The study group comprised of 72 children with a median age of 3.7 years and boys: girls ratio of 1.9:1. Twenty two of 72 (30.5%) developed NP; the predominant isolates from ETA were Acinetobacter anitratus(12), Pseudomonas aeruginosa (5), Klebsiella sp(3) and Staphylococcus aureus and E.coli(1) each. Additionally 18(39%) had evidence of ET colonization, with Acinetobacter sp being the commonest 9(50%). Re-intubation, prolonged duration of intubation and mechanical ventilation were the significant risk factors on univariate analysis for development of NP. On multiple regression analysis, reintubation was the only independent risk factor for NP(OR 0.72, 95%CI 0.55-0.94). Overall mortality was 21%(15/72);7(47%)of these deaths were secondary to NP.

Conclusions: NP developed in nearly one third of the intubated patients; Gram negative organisms were the predominant etiological agents and associated with high mortality. Re-intubation, prolonged duration of intubation and mechanical ventilation were the significant risk factors on univariate analysis for development of NP. On multiple regression analysis, reintubation was the only independent risk factor for NP.