铜绿假单胞菌和不动杆菌引起的院内感染 ,使用单一抗菌药通常很难根除 ,而使用联合疗法可以扩大抗菌谱、减小毒性和预防耐药突变株的出现。对于严重感染应考虑使用左氧氟沙星或环丙沙星与其它抗生素联用 ,本研究的目的比较左氧氟沙星或环丙沙星与阿米卡星、头孢吡肟、头孢他啶 Pseudomonas aeruginosa and Acinetobacter nosocomial infections, the use of a single antibacterial drug is usually difficult to eradicate, and the use of combination therapy can expand the antibacterial spectrum, reduce toxicity and prevent the emergence of drug-resistant mutant strains. For serious infections should consider the use of levofloxacin or ciprofloxacin combined with other antibiotics, the purpose of this study to compare levofloxacin or ciprofloxacin and amikacin, cefepime, ceftazidime