Research Of Trans-bronchoscopic Catheter Aspiration For The Etiological Diagnosis Of Severe Pneumonia

Objective:By comparing different trans-bronchoscopic sampling methods for etiological diagnosis of severe pneumonia,this study aimed to explore the feasibility of sampling by trans-bronchoscopic catheter aspiration and its significance for etiological diagnosis of severe pneumonia.Methods : Select 60 patients with severe pneumonia who had underwent invasive mechanical ventilation in the ICU of Respiratory Department of Shaoyang Central Hospital and 30 outpatients without pulmonary infection from December 2014 to December 2015,all the patients were observed for any adverse reactions with trans-bronchoscopic catheter aspiration,and the sampling methods including trans-bronchoscopic catheter aspiration,trans-bronchoscopic direct sputum aspiration and alveolar lavage were compared for pathogen positivity in sputum culture obtained by these methods,as well as the sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of these methods.Results : 1.All the 90 patients completed trans-bronchoscopic catheter aspiration successfully without experiencing any adverse reaction.2.The sputum culture positivity was 75%,38.3% and 56.7%,respectively,when using trans-bronchoscopic catheter aspiration,trans-bronchoscopic direct sputum aspiration and alveolar lavage,where trans-bronchoscopic catheter aspiration showed statistically significant differences from both trans-bronchoscopic direct aspiration and alveolar lavage(χ2=16.43,P<0.005;χ2=4.48,P<0.05).The sensitivity of the three methods was 75%,38.3% and 56.7%,respectively,where trans-bronchoscopic catheter aspiration showed statistically significant differences from both trans-bronchoscopic direct aspiration and alveolar lavage(χ2=16.43,P<0.005;χ2=4.48,P<0.05).The specificity was 100%,96.67% and 96.67%,respectively,where trans-bronchoscopic catheter aspiration showed no statistically significant difference from trans-bronchoscopic direct aspiration or alveolar lavage(χ2=1.02,P﹥0.05;χ2=1.02,P﹥0.05).The accuracy was 83.33%,57.78% and 70.00%,respectively,where trans-bronchoscopic catheter aspiration showed statistically significant differences from both trans-bronchoscopic direct aspiration and alveolar lavage(χ2=15.24,P<0.005,χ2=4.47,P<0.05).The positive predictive values were 100.00%,95.83% and 97.14%,respectively,where trans-bronchoscopic catheter aspiration showed no statistically significantdifference from trans-bronchoscopic direct aspiration or alveolar lavage(Fisher’s exact probability test for fourfold table,P=0.35,P=0.44);the negative predictive values were 66.67%,43.94% and 52.73%,respectively,where trans-bronchoscopic catheter aspiration showed statistically significant difference from trans-bronchoscopic direct aspiration(χ2=5.55,P<0.05),and no statistically significant difference from alveolar lavage(χ2=1.99,P﹥0.05).Conclusion : 1.Sampling with trans-bronchoscopic catheter aspiration is feasible in clinical practice.2.Sampling by trans-bronchoscopic catheter aspiration could improve pathogen positivity in etiological diagnosis of severe pneumonia,which,in addition to high sensitivity and accuracy,supports its further application.