Niederman M S
Department of Medicine and the Division of Pulmonary and Critical Care Medicine, Winthrop-University Hospital, Mineola, NY, USA.
Crit Care Med. 2001 Apr;29(4 Suppl):N114-20. doi: 10.1097/00003246-200104001-00011.
Antibiotic-resistant organisms are common in intensive care unit infection and can be either Gram-positive or Gram-negative. A number of studies have evaluated whether these organisms can lead to excess morbidity, mortality, or cost. In general, the studies are confounded by a number of methodologic issues, including the selection of an appropriate control population. Cases and controls must be appropriately matched for the presence of infection, the presence of infection with similar organisms (but ones that are either antibiotic-sensitive or -resistant), and severity of illness. In addition, studies must account for the therapies given to patients who are infected with resistant organisms because resistance is an important risk factor for inadequate empirical therapy, and such therapy is itself a potent determinant of a number of adverse outcomes, including mortality. To date, the data with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus are inconsistent with regard to the effect on mortality rates, although infection with both organisms can lead to excess length of stay and increased cost of care. When studies have been adequately controlled and powered, infection with vancomycin-resistant enterococcus has had more of an effect on the mortality rate than infection with antibiotic-sensitive enterococci. Infection with resistant Gram-negatives also has adverse impact on outcome, with excess mortality being seen in patient groups infected with Acinetobacter and Pseudomonas aeruginosa. If we are to minimize the effect of resistance on medical outcomes and cost, it will be necessary to have a current knowledge of each intensive care unit's pathogens and susceptibility patterns, so that empirical therapy will have a good likelihood of being effective. In addition, new therapeutic agents may improve on the efficacy of older agents and could reduce cost if they allow for some patients to leave the hospital and to finish therapy with an oral formulation of a highly bioavailable agent.
耐抗生素微生物在重症监护病房感染中很常见，可为革兰氏阳性菌或革兰氏阴性菌。许多研究评估了这些微生物是否会导致更高的发病率、死亡率或成本。总体而言，这些研究受到一些方法学问题的困扰，包括选择合适的对照人群。病例和对照必须在感染的存在、相似微生物（但对抗生素敏感或耐药）感染的存在以及疾病严重程度方面进行适当匹配。此外，研究必须考虑给予感染耐药微生物患者的治疗，因为耐药是经验性治疗不足的重要危险因素，而这种治疗本身是包括死亡率在内的许多不良结局的有力决定因素。迄今为止，关于耐甲氧西林金黄色葡萄球菌和耐万古霉素肠球菌的数据在对死亡率的影响方面并不一致，尽管感染这两种微生物都会导致住院时间延长和护理成本增加。当研究得到充分控制且有足够的样本量时，耐万古霉素肠球菌感染对死亡率的影响比对抗生素敏感肠球菌感染的影响更大。革兰氏阴性耐药菌感染也会对结局产生不利影响，在感染不动杆菌和铜绿假单胞菌的患者群体中可见死亡率过高。如果我们要尽量减少耐药性对医疗结局和成本的影响，就有必要了解每个重症监护病房当前的病原体和药敏模式，以便经验性治疗有很大的有效可能性。此外，新的治疗药物可能会提高旧药物的疗效，如果它们能让一些患者出院并用高生物利用度药物的口服制剂完成治疗，还可以降低成本。
