Donnelly J P
Department of Haematology, University Hospital, Nijmegen, The Netherlands.
J Antimicrob Chemother. 1993 Jun;31(6):813-29. doi: 10.1093/jac/31.6.813.
Selective decontamination of the digestive tract (SDD) is an established form of infection prevention which relies upon local antibiotic action to afford suppression of potential pathogens while preserving 'colonization resistance' (CR). However, CR has never been shown conclusively to play a decisive role in either achieving or maintaining effective prophylaxis in patients and by employing absorbable antimicrobials or parenteral antibiotics, prophylaxis is actually achieved by both local and systemic action. The role of prophylaxis in neutropenic patients is also far from clear since morbidity and mortality remain the same whether or not prophylactic antibacterials are given and most patients still require empirical therapy for fever. In addition, the Gram-positive cocci, rather than Gram-negative bacilli presently predominate as pathogens. There is also an increasing trend towards including fungal and viral infection as targets for prophylaxis. Moreover, current anti-infective strategies are more akin to 'pre-emptive therapy' (PET) since the antimicrobials are available systemically and given at optimum therapeutic doses and there is little to distinguish treatment given to prevent colonization from progressing to infection from that used to arrest incipient infection or effect a cure of established infection. In contrast, SDD as originally conceived may well prove cost-effective for the prevention of infection in intensive care although neither the optimum regimen nor the patient group who would gain most benefit have been defined. None the less, by affording protection against Gram-negative sepsis, both SDD and PET would reduce the pressure on the clinicians to treat empirically and shift the emphasis once more on appropriate investigations which would involve the microbiologist more directly and immediately in patient care. Any savings from lowering the drug usage could then be diverted to improving diagnosis and providing the regular monitoring that is essential to the success of both PET and SDD.
消化道选择性去污（SDD）是一种既定的感染预防形式，它依靠局部抗生素作用来抑制潜在病原体，同时保留“定植抗力”（CR）。然而，从未有确凿证据表明CR在患者实现或维持有效预防方面起决定性作用，而且通过使用可吸收抗菌药物或肠外抗生素，预防实际上是通过局部和全身作用实现的。预防在中性粒细胞减少患者中的作用也远未明确，因为无论是否给予预防性抗菌药物，发病率和死亡率都保持不变，而且大多数患者仍需要针对发热进行经验性治疗。此外，目前作为病原体的主要是革兰氏阳性球菌，而非革兰氏阴性杆菌。将真菌和病毒感染纳入预防目标的趋势也在增加。此外，当前的抗感染策略更类似于“抢先治疗”（PET），因为抗菌药物可全身获得并以最佳治疗剂量给药，而且预防定植进展为感染所给予的治疗与用于阻止初期感染或治愈已确诊感染的治疗几乎没有区别。相比之下，最初设想的SDD在预防重症监护中的感染方面可能很有成本效益，尽管尚未确定最佳方案或最能从中受益的患者群体。尽管如此，通过提供针对革兰氏阴性败血症的保护，SDD和PET都将减轻临床医生进行经验性治疗的压力，并再次将重点转向适当的检查，这将使微生物学家更直接、更及时地参与患者护理。然后，因减少药物使用而节省的任何费用都可转而用于改善诊断并提供PET和SDD成功所必需的定期监测。
