下呼吸道感染是一组多发病、常见病,往往反复发作,不断加重支气管、肺组织的病理损害,促使形成慢性阻塞性肺气肿、肺心病。近年来,由于抗生素的滥用及器械检查的增加,医院获得性肺炎发病率、病死率均较高,肺部感染的病原谱亦有较大变化,革兰氏阴性杆菌取代了革兰氏阳性球菌成为主要致病菌。该类细菌常对多类抗生素耐药,造成临床治疗困难,尤其对老年人及肿瘤、免疫功能低下等病患者构成严重危害。用于治疗下呼吸道感染的抗菌药物品种较多,常用的大环内酯类、第一代头孢菌素主要针对革兰氏阳性球菌,后者对革兰氏阴性杆菌复盖面窄,而氨基糖苷类因肾、耳毒性,其应用受一定限制。 Lower respiratory tract infection is a group of frequently-occurring disease, common disease, often recurrent, increasing the bronchial, lung tissue pathological damage, prompting the formation of chronic obstructive pulmonary emphysema, pulmonary heart disease. In recent years, due to the abuse of antibiotics and the increase of equipment inspection, the incidence of hospital-acquired pneumonia and case fatality were high, and the pathogenic spectrum of lung infection also changed greatly. Gram-negative bacilli replaced Gram-positive cocci Become the main pathogen. Such bacteria often resistant to many types of antibiotics, resulting in clinical treatment difficulties, especially for the elderly and cancer, immune dysfunction and other diseases constitute a serious hazard. For the treatment of lower respiratory tract infections more antibacterial drugs, commonly used macrolides, first-generation cephalosporins mainly against Gram-positive cocci, the latter of Gram-negative bacilli coverage narrow, and amino Glycosides due to kidney, ototoxicity, its application is subject to certain restrictions.