Croce M A, Fabian T C, Stewart R M, Pritchard F E, Minard G, Trenthem L, Kudsk K A
Department of Surgery, University of Tennessee, Memphis.
J Trauma. 1993 Aug;35(2):303-9; discussion 309-11. doi: 10.1097/00005373-199308000-00022.
Combination therapy for nosocomial pneumonia with a beta-lactam and aminoglycoside is widely accepted because of synergy and reduction of resistant bacteria. This prospective study of 109 trauma patients (94 blunt, 15 penetrating) with nosocomial pneumonia was performed in consecutive phases. In phase 1, patients were randomized to an anti-pseudomonal third-generation cephalosporin--cefoperazone or ceftazidime. Gentamicin was added to each regimen in phase 2. The mean age of the patients was 37 years, the mean ISS was 31, and there were no differences among the four treatment groups relative to associated injuries. Patients receiving monotherapy had a 56% cure rate compared with 31% for combination therapy (p < 0.04). Persistence rates were similar in these two groups (15% and 20%), but superinfection was significantly higher in the combination group (49% vs. 28%; p < 0.04). The predominant superinfecting organism was methicillin-resistant Staphylococcus aureus (MRSA). Nine patients died (5% monotherapy, 10% combination), and eight had a superinfection. We conclude that monotherapy had a higher cure rate than combination therapy for empiric therapy of pneumonia in our trauma patients. Combination therapy failed because of superinfection (primarily MRSA). Emergence of MRSA may be from host overgrowth or plasmid-mediated induction of resistance, possibly caused by gentamicin.
β-内酰胺类药物与氨基糖苷类药物联合治疗医院获得性肺炎因具有协同作用且能减少耐药菌而被广泛接受。本前瞻性研究连续分阶段纳入了109例患有医院获得性肺炎的创伤患者（94例钝性伤，15例穿透伤）。在第1阶段，患者被随机分为接受抗假单胞菌第三代头孢菌素——头孢哌酮或头孢他啶治疗。在第2阶段，每种治疗方案中均加用庆大霉素。患者的平均年龄为37岁，平均损伤严重度评分（ISS）为31，四个治疗组在相关损伤方面无差异。接受单药治疗的患者治愈率为56%，而联合治疗组为31%（p<0.04）。这两组的持续感染率相似（分别为15%和20%），但联合治疗组的二重感染率显著更高（49%对28%；p<0.04）。主要的二重感染病原体是耐甲氧西林金黄色葡萄球菌（MRSA）。9例患者死亡（单药治疗组5%，联合治疗组10%），8例发生二重感染。我们得出结论，在我们的创伤患者中，经验性治疗肺炎时单药治疗的治愈率高于联合治疗。联合治疗因二重感染（主要是MRSA）而失败。MRSA的出现可能源于宿主菌过度生长或质粒介导的耐药性诱导，可能是由庆大霉素引起的。
