Change Of Pathogens And Risk Factors For Ventilator-associated Pneumonia In Infants With Congenial Heart Disease After Surgery

Objective: To investigate the pathogens distribution, drug sensitivity and risk factors of children with ventilator-associated pneumonia after cardiac surgeries of congenital heart diseases, and provide the basis for the clinical prevention from VAP.Methods: A Retrospective analysis has been made on the patients in the PICU who received mechanical ventilation for 48 hours or longer after cardiac surgeries of congenital heart diseases from January 2012 to December 2014. In accordance with the clinical manifestation, laboratory examination and sputum culture, we divided the patients into VAP group and non-VAP group. The pathogens of VAP group in sputum were cultured and related drug sensitivity was analyzed; the risk factors of postoperative VAP in patients with congenital heart disease were analyzed by logistic regression analysis.Results:312 cases of patients received mechanical ventilation for more than 48 h, in which 53 cases were complicated by VAP. The incidence of VAP is 17.0%. The sputum culture of 51 cases was positive in 53 cases with VAP, and the others were diagnosed with VAP according to higher temperature, emerging pulmonary crackles, increased inflammatory markers and abnormal X-ray. The results of sputum culture showed 63 positive strains including 49 strains Gram-negative bacteria(77.8%), 9 strains Gram-positive bacteria(14%) and 5 strains fungi(8%).The drug sensitivity tests indicated that there gram-negative pathogens had resistance to cefotaxime, ceftazidime and amoxicillin, piperacillin, with a resistance rate of above 74%, and demonstrated sensitivity to amikacin, polymyxin and meropenem(resistance rate of 19%~32%). The resistance rate of gram-positive pathogens to sulfonamide and penicillin is higher, but the test indicated that all of the gram-positive pathogens had sensitivity to vancomycin. Moreover, Fungi were sensitive to the common antifungal drugs such as 5- fluorine cytosine, amphotericin B, itraconazole and fluconazole. Single factor analysis showed albumin levels, preoperative antibiotics, preoperative pulmonary infection, duration of mechanical ventilation, times of tracheal intubation, times of anesthesia agents, duration of cardiopulmonary bypass, times of aortic occlusion and the use of histamin2-receptor blockade were significant different between the two groups(P<0.05); Logistic regression was analyzed for related factors, the result of which showed that albumin levels <35(g/L), duration of mechanical ventilation≥7d, times of tracheal intubation≥3, duration of cardiopulmonary bypass≥100 min and times of aortic occlusion≥60 min were independent risk factors for VAP in children with congenial heart disease after surgery.Conclusions : The main pathogens for VAP in children with congenial heart disease after surgery are Gram-negative bacteria. The antibiotics should be used reasoningly according to the pathogen distribution and drug sensitivity test results. Based on related risk factors of VAP, efficient measures should be taken to reduce the morbidity of VAP in children after cardiac surgeries of congenital heart diseases.