Abstract:Objective To explore the value of loop-mediated isothermal amplification （LAMP） chip in analyzing the etiology of bronchoalveolar lavage fluid （BALF） for diagnosing hospital acquired pneumonia （HAP）. Methods Of 457 patients with HAP in Zhongda Hospital of Southeast University from December 2018 to December 2019, 82 patients （44 males and 38 females） were selected to take BALF specimens for simultaneous detection of pathogens by LAMP chip and routine bacterial culture. Results The positive rates of pathogens were 37.80% （31 cases） detected by LAMP chip and 32.93% （27 cases）detected by routine bacterial culture. There was a good agreement in detecting the pathogens by LAMP chip and conventional bacterial culture（Kappa=0.756，P＜0.05）， especially in Acinetobacter baumannii （18.29% vs 14.63%, Kappa=0.779）, followed by Pseudomonas aeruginosa （17.07% vs 10.98%, Kappa=0.749） and Klebsiella pneumoniae （9.76% vs 3.66%, Kappa=0.520）. The overall positive rate for 13 pathogens detection by LAMP chip was statistically higher than that by bacterial culture（74.39% vs 31.71%, P＜0.01）. LAMP chip method had the better detection effect on methicillin-resistant Staphylococcus aureus （8.54% vs 0, P＜0.05） and common respiratory pathogens, such as Tubercle bacilli, Legionella, Mycoplasma and Chlamydia, which weren't determined by ordinary bacterial culture. Conclusion LAMP chip can quickly detect common respiratory pathogens in BALF of HAP patients, which is helpful for the early identification of HAP pathogens and provides rapid and reliable laboratory evidence for targeted treatment.