Etiology And Risk Factors Of Late-Onset Hospital-Acquired Pneumonia In Respiratory Intensive Care Unit

Objective:To explore the clinical feature,risk factors,etiology and prognosis of late-onset hospital-acquired pneumonia(L-HAP) in respiratory ICU.Method:In retrospective case control study,30 L-HAP patients in respiratory ICU and 30 ICU patients without HAP were enrolled to investigate the features and risk factors of L-HAP.Stratification was made according to the onset time of L-HAP,we described the etiology of each stage and analyzed the possible risk factors and pathogen distribution according to the coverage of antibiotics before onset.Results:L-HAP occurred on the day 6 to day 53 after admission,on the average of day 22.1±12.7.The monofactor of L-HAP was unconsciousness,aspiration,tracheal intubation or incision receiving mechanical ventilation,hypoalbuminemia,long-term use of proton pump inhibitor.The Logistic binary regression showed that mechanical ventilation and hypoalbuminemia were independent risk factor of HAP.Compared to the control group,patients that had longer stay in hospital and antibiotic usage,and also had higher mortality in L-HAP group.Gram negative bacilli accounted for 71.4%of pathogen in L-HAP.Acinetobacter baumannii,Pseudomonas aeruginosa and Staphylococcus aureus accounted for 62.5%,28.6%and 25.0%of mortalily respectively.In different period,sex,age,underlying diseases were similar,but the antibiotics usage before HAP onset within seven days was quite different.The continuous use of antibiotics in the first period(6.2±1.3 days) was mainly the 3rd and 4th cephalosporin,the second period(6.3±1.4 days) with mainly use of the 3rd and 4th cephalosporin,β-1actam/enzyme inhibitor and quinolone,and the third period (6.8±0.4 days) with mainly use of the 3rd and 4th cephalosporin and carbapenem, respectively.The incidence of negative sputum culture in each period was 11.1%, 16.7%,66.7%,respectively.Subgroup study showed that pathogen of each stage was different,the pathogen of the first period was mainly Acinetobacter baumannii, and in second period Pseudomonas aeruginosa,Acinetobacter baumannii and Staphylococcus aureus were dominated,and the third period is mainly Pseudomonas aeruginosa. Conclusion:The independent risk factors of L-HAP were mechanical ventilation and hypoalbuminemia.The onset of L-HAP promoted the patients death,increased the length of RICU stay and use of antibiotics.The pathogen features of L-HAP were closely associated with the use of antibiotics before onset.Each stage had characteristic pathogen.