Virus Etiology And Prognosis Analysis Of Severe Pneumonia In Adults With Mechanical Ventilation

BackgroundThe prognosis of severe pneumonia is poor,and the mortality rate is as high as17%-49%.Foreign research show that viral pneumonia accounts for 22% of community-acquired pneumonia.The current research on viral pneumonia is mostly focused on patients with mild symptoms,and there are few reports on the epidemiology of respiratory viruses in adult patients with severe pneumonia on mechanical ventilation.The relationship between the positive respiratory virus and the clinical situation in patients with severe pneumonia still needs to be further studied.ObjectiveScreen the prevalence of respiratory viruses in adult patients with severe pneumonia which needed mechanical ventilation.Explore the similarities and differences of the test results of throat swabs,ETA,and BALF.Explore the correlation between positive respiratory virus and clinical.Materials and MethodsThis study is a single-center prospective observational study.From March 1,2019 to June 30,2020,a total of 115 cases of adult mechanically ventilated severe pneumonia in the Critical Care Medicine Department of the First Affiliated Hospital of Guangzhou Medical University were included.Patient’s throat swabs,endotracheal aspiration,and bronchoalveolar lavage fluid were taken to detect 25 common respiratory viruses within 48 hours of enrollment and on the 7th day.And record its demographic data and vital signs.Detect inspection index of respiratory,heart,liver,kidney,coagulation,infection,immunity and other functions.Radiological findings were also recorded.Survival status was followed up 90 days after enrollment.Primary outcome was 90-day survival.Secondary outcome include: time of mechanical ventilation,ICU stay,hospitalization stay,and total hospitalization expenses.The purpose of this study is to obtain the etiology of severe pneumonia,the similarities and differences of virus test results of three different airway secretions,and the relationship between virus positive and prognosis.Results1.A total of 115 adult patients with severe pneumonia which needed mechanical ventilation were enrolled from March 1,2019 to June 30,2020,of which60.00% were respiratory virus-positive patients.2.Among the respiratory viruses,the positive rate in order is: human cytomegalovirus 43(37.39%),adenovirus 13(11.30%),influenza virus type A H1N120096(5.22%),etc.Nineteen patients(16.52%)had mixed infections of two respiratory viruses.One person(0.87%)had a combined infection of three respiratory viruses.Eight people(6.96%)had a new viral infection in the hospital.3.The respiratory secretions of different parts were collected for virus detection,and the virus positive detection rate: BALF approximate to ETA> throat swab.Viral load: BALF>ETA>throat swab.Ct value: throat swab>ETA(29.45(27.51-36.11)vs.19.79(20.79-31.66),P=0.001);ETA>BALF(27.02±7.13 vs.24.16±6.07,P=0.04);throat swab>BALF(27.96±4.17 vs.23.42±7.17,P=0.02).4.The 90-day mortality rate of the virus-positive group was 27.54%,and the90-day mortality rate of the virus-negative group was 32.61%.There was no statistical difference between them.Compared with the virus-negative group,the virus-positive group had more in days of invasive mechanical ventilation(32.00(13.00-60.00)vs.17.00(10.00-34.25),P=0.02),days of ICU hospitalization(36.00(17.00-60.50)vs.22.00(12.75-38.00),P=0.02),days of total hospitalization(51.00(34.50-77.50)vs.32.00(21.00-58.25),P<0.01),the total hospitalization cost(ten thousand yuan)(28.88(10.32-55.06)vs.17.02(6.67-45.68),P=0.04).Conclusion60% of mechanically ventilated patients with severe pneumonia tested positive for respiratory virus nucleic acid.Bronchoalveolar lavage fluid has a higher virus-positive detection rate and viral load.Compared with the virus-negative group,although the 90-day mortality rate of the virus-positive group is not different,the mechanical ventilation time,ICU stay time,total length of hospital stay and hospitalization costs increased.