Clinical Research Directory

Inclusion Criteria: * Age 18 years and above * The preliminary clinical diagnosis is a patient with lower respiratory tract infection * Meets the criteria for severe pneumonia, which means one of the following conditions exists: ① Main criteria: septic shock requiring vasoactive drug support; Respiratory failure requiring mechanical ventilation; ② Secondary criteria: Meet at least 3 or more criteria, including respiratory rate\>30 times/minute; Oxygenation index (PaO ₂/FiO ₂)\<250; Multiple leaf segment infiltration; Consciousness disorders/orientation disorders; Urea nitrogen level\>20mg/dL; White blood cell count\<4 \* 10 \^ 9/L; platelet count\<100 \* 10 \^ 9/L; core body temperature\<36.8 ° C; hypotension requiring active fluid resuscitation * The patient agrees to undergo bronchoscopy and bronchoalveolar lavage, and agrees to perform AI-ROSE testing on the bronchoalveolar lavage fluid Exclusion Criteria: * Patients with poor basic condition, severe illness, and inability to tolerate bronchoscopy examination * The bronchoalveolar lavage fluid sample is not qualified