Artificial ventilation as a risk factor causing hospital-acquired pneumonia (hap) in patients treated in the intensive care unit of a cardiac surgery hospital

Abstract

Hospital-acquired pneumonia (HAP) is the most common purulent septic infection among patients treated in intensive care units (ICUs) at cardiac surgery hospitals. Risk factors that can cause HAP, in particular, contribution made by artificial ventilation (AV) have not been studied enough. Our objective was to examine an epidemiological role played by AV in HAP occurrence among children and adults treated in the intensive care unit at a cardiac surgery hospital. We examined health records of 5318 patients (503 children and 4815 adults) who had a cardiac surgery due to congenital heart diseases or acquired cardiovascular disorders over 1 year. HAP was identified according to the epidemiological standards for case definition. Besides, we took into account pre-nosologic HAP cases, that is, patients already having certain pathological symptoms typical for purulent septic infections, but still, even combined, these symptoms were not enough to diagnose a typical HAP case in accordance with the standard case definition. Data were statistically analyzed by calculating the χ2 goodness-of-fit test. We established that most HAP cases occurred among patients of a cardiac surgery hospital who were being treated in the intensive care unit after a surgery. We proved AV to be the leading risk factor causing HAP. Higher incidence rates of HAP were detected among children in comparison with adults. We showed that Klebsiella pneumoniaе was the primary infectious agent that caused HAP. Particularly, background respiratory diseases and diseases of the central nervous system were proven to be endogenous risk factors of developing HAP among patients treated in the ICU at a cardiac surgery hospital.