Risk factor analysis of pneumonias developing after open heart surgery

Introduction

Pneumonia after cardiac surgery have an important role among the infections that originate from hospitals as they increase mortality, morbidity and costs. To decrease the pneumonia incidence after open heart surgery, we should analyse the risk factors correctly and eliminate the preventable risk factors.

Methods

In our study 1000 consecutive patients who had open heart surgery since January 2002 in Siyami Ersek Thoracic and Cardiovascular Surgery Center were followed about pneumonia prospectively. Pneumonia is defined with Center of Disease Control–ABD criteria. In identifications of microorganisms, classical methods and BBL Chrystal Gram Positive ve BBL Gram Negative (Becton Dickenson) kits were used. Data have been analysed statistically in the SPSS for Windows 10.0 programme. In univariant analysis a t test was used, in group variants chi square tests were used. P < 0.05 was considered statistically significant. To determine the independent risk factors multivariant logistic regression analysis was used.

Results

In 991 patients, data were found suitable for the study. The mean patients' age is 57.6 ± 13 years. Demographic data of the patients are shown in Table 1. The pneumonia ratio is 1000 device day/12.5. By univariant analysis age, emergency operation, low EF, operation time, intubation time, respiratory interventions, reintubation, enteral feeding, reoperation, resuscitation, presence of any complication, readmission to the ICU, and usage of blood derivatives are found to be the risk factors for pneumonia after cardiac surgery. Independent risk factors of pneumonia development are shown in Table 2.

Table 1

Table 2

Conclusion

Nosocomial pneumonia is one of the most significant infections among cardiac surgery patients in the postoperative period. In different studies the frequency of nosocomial pneumonia was found between 0.2% and 9.7% and the mortality rate between 23% and 51%. According to our study older age and emergency-operated patients are under higher risk of pneumonia after cardiac surgery. The risk factors like intubation time, enteral feeding, usage of blood and blood derivatives must be controlled in preoperative, intraoperative and postoperative periods.