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Critical Care Research and Practice
Volume 2010, Article ID 501031, 11 pages
http://dx.doi.org/10.1155/2010/501031
Review Article

Selective Decontamination of the Digestive Tract Reduces Pneumonia and Mortality

1Department of Intensive Care Medicine, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
2Laboratory of Experimental Intensive Care and Anesthesiology (L.E.I.C.A), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands

Received 29 July 2010; Accepted 20 September 2010

Academic Editor: J. L. Vincent

Copyright © 2010 Lenneke E. M. Haas and Marcus J. Schultz. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Selective decontamination of the digestive tract (SDD) has been subject of numerous randomized controlled trials in critically ill patients. Almost all clinical trials showed SDD to prevent pneumonia. Nevertheless, SDD has remained a controversial strategy. One reason for why clinicians remained reluctant to implement SDD into daily practice could be that mortality was reduced in only 2 trials. Another reason could be the heterogeneity of trials of SDD. Indeed, many different prophylactic antimicrobial regimes were tested, and dissimilar diagnostic criteria for pneumonia were applied amongst the trials. This heterogeneity impeded interpretation and comparison of trial results. Two other hampering factors for implementation of SDD have been concerns over the risk of antimicrobial resistance and fear for escalation of costs associated with the use of prophylactic antimicrobials. This paper describes the concept of SDD, summarizes the results of published trials of SDD in mixed medical-surgical intensive care units, and rationalizes the risk of antimicrobial resistance and rise of costs associated with this potentially life-saving preventive strategy.

1. Introduction

Potentially pathogenic microorganisms such as Gram-negative bacteria (including Pseudomonas aeruginosa), Gram-positive bacteria (including Staphylococcus aureus), and yeasts rapidly colonize stomach and intestines of critically ill patients [1]. Retrograde colonization of the oral cavity and throat may occur, and microaspiration into the lung could eventually result in pneumonia [2]. Prevention of colonization of oral cavity, throat, stomach, and intestines could reduce the incidence of respiratory tract infections, thereby improving outcome of intensive care unit (ICU) patients.

Selective decontamination of the digestive tract (SDD) is one strategy to prevent colonization of oral cavity, throat, stomach, and intestines of ICU patients. Numerous randomized controlled clinical trials have suggested SDD a beneficial strategy. Indeed, reductions in the incidence of pneumonia have been achieved with the use of SDD in critically ill patients [3]. However, only 2 trials showed SDD to reduce mortality [4, 5]. This may have caused caregivers to become indisposed to apply this strategy in daily practice. In addition, fear for emergence of antimicrobial resistance and escalation of costs associated with SDD, at least in part, hampered widespread implementation of this preventive strategy.

It should be noticed that the concept of colonization and infection as presented by Stoutenbeek and van Saene concerned trauma patients. It can be questioned whether this concept holds true for other ICU patients. Indeed, these patients are older, have significant comorbidities, and are frequently on antibiotics already at or before admission to the ICU.

We here describe the concept of SDD. We summarize the numerous clinical trials of SDD, focusing on trials applying the original SDD strategy in mixed medical-surgical ICUs and having pneumonia and/or mortality as a primary endpoint. Concerns over bacterial resistance and costs associated with SDD are discussed and rationalized.

2. ICU-Related Infections

2.1. Incidence and Outcome

ICU-related infections, in particular pneumonia, constitute a major problem during critical illness [6, 7]. Up to 50% of critically ill patients develop pneumonia [8]. When critically ill patients develop pneumonia, ICU and hospital mortality may double [9]. In accordance, patients with pneumonia need mechanical ventilation for a longer period of time and have a prolonged stay in ICU and hospital [10, 11]. Consequently, costs rise when pneumonia develops [1214].

2.2. Primary and Secondary Endogenous versus Exogenous Infections

ICU-related infections can be classified into primary endogenous, secondary endogenous, and exogenous infections [15].

Primary endogenous infections are caused by pathogens carried in throat, stomach, and/or intestines of patient on ICU-admission. They occur generally within one week after admission and can be prevented by parenteral antibiotics administered directly after admission to the ICU.

Secondary endogenous infections may also occur soon after admission to the ICU. Contrary to primary endogenous infections, pathogens involved with secondary endogenous infections are not carried in throat, stomach, and/or intestines on admission but acquired during stay in ICU, and mostly from other patients via the hands of caregivers. Most of these infections could be banned if colonization is prevented.

Exogenous infections can occur at any time during stay in ICU and occur when exogenous pathogens are accidentally introduced into a sterile internal organ without previous carriage.

2.3. Pathogenic Microorganisms of ICU-Related Infections

Micro-organisms differ in their pathogenicity. For example, fast majorities of ICU patients carry Enterococcus spp. in high concentrations in the intestines; infections caused by these microorganisms are rare. Conversely, 30%–40% of ICU patients who carry aerobic Gram-negative bacteria (including P. aeruginosa and Klebsiella spp.) in the oral cavity, throat or intestines develop an infection caused by these organisms.

The pathogenicity can be expressed in the Intrinsic Pathogenicity Index (IPI) [16]. IPI is number of patients infected by species /number of patients carrying species in throat or intestines. The range of IPI is from 0 to 1. Carriage of a microorganism with an IPI close to 0 will seldom be followed by an infection. Carriage of a microorganism with an IPI close to 1 will almost always be followed by an infection. According to the IPI, microorganisms can be divided in low, potentially and highly pathogenic microorganisms (Table 1). Prevention of carriage with pathogens with an IPI close to 1 is thought to benefit ICU patients.

tab1
Table 1: Pathogenicity of microorganisms.

3. Prevention of ICU-Related Infections

3.1. Selective Decontamination of the Digestive Tract

Multiple strategies to reduce the incidence of respiratory infections in ICU patients have been evaluated, including SDD. Van der Waaij et al. were the first to describe the concept of SDD in 1971 [17]. The concept of SDD is based on colonization resistance—the intact, anaerobic intestinal flora is protective against secondary colonization with Gram-negative aerobic bacteria. Disturbance or loss of this anaerobic flora leads to increased colonization and increased risk of infection with facultative aerobic bacteria. SDD should prevent colonization with aerobic Gram-negative bacteria and other pathogens, without disrupting the anaerobic flora with the aim to reduce the incidence of secondary infections.

3.2. Components of SDD

SDD classically consists of 4 components [18] (Figure 1): (I)selective eradication of pathogenic microorganisms in the oral cavity and decontamination of the stomach and intestines by local administration of nonabsorbable antimicrobial agents—the first is reached by application of a paste, gel, or lozenge to the oropharynx, the second by administration of a suspension through a nasogastric tube; (II)systemic prophylaxis by a short course of an intravenous antimicrobial agent—to prevent respiratory infections that may occur during the ICU stay, caused by commensal respiratory flora;(III)high levels of hygiene to prevent cross-contamination;(IV)surveillance cultures (regular cultures of throat swabs and feces/rectum) to monitor the effectiveness of SDD.

501031.fig.001
Figure 1: The 4 components of the original SDD regimen.

It has been suggested that failure to apply this complete 4-component model reduces the effectiveness of SDD [19], although this has neither been tested nor proven.

4. Studies of SDD

4.1. Search Strategy

We identified relevant publications on SDD by searching the PubMed, EMBASE, and Cochrane Library databases using the following terms or MeSH subject heading: [intensive care], [critical care], [critical illness], [critical mortality], [infections], [pneumonia], [infection control], [selective digestive decontamination], [antibiotic prophylaxis], [antibacterial agents/therapeutic use], [bacterial infections/prevention and control], [drug resistance (microbial/bacterial)], [costs and cost analysis], [cost–benefit analysis], [cost-effectiveness analysis], [economics], [drug costs], and [health care costs]. Reference lists from identified citations and relevant review articles were hand searched for additional potentially relevant publications and abstracts.

With this search strategy, trials analyzing the oral decontamination strategy were also found, but subsequently we focused on the complete SDD regimen. We also restricted our search to trials performed in mixed medical-surgical ICUs and to studies that had pneumonia and/or mortality as the primary endpoint. Adjacent to this, we looked for studies that focused on antimicrobial resistance induced by SDD and studies that analyzed costs of SDD treatment.

4.2. Search Results

The search yielded 336 manuscripts of potential interest. Studies that were performed in specific subgroups of ICU-patients, such as neurosurgical patients, liver transplant patients, burn patients, trauma patients, patients with severe pancreatitis, and patients after open-heart surgery, after gastrectomy or after oesophageal resection, were excluded. We also excluded studies of SDD in the pediatric ICU setting. We subsequently focused on mortality and pneumonia, antimicrobial resistance, and costs. This left us with 20 publications on trials (Table 2), and 15 meta-analyses (Table 3). addition, our search yielded several publications dealing with antimicrobial resistance (Table 4) and costs of SDD, respectively.

tab2
Table 2: Incidence and relative risks of pneumonia and mortality in trials of SDD in mixed medical-surgical ICUs.
tab3
Table 3: Odds ratios for pneumonia and mortality in meta-analyses of trials of SDD.
tab4
Table 4: SDD and the emergence of antimicrobial resistance, in areas with high and low endemicity.
4.3. Study Heterogeneity

Although we focused on trials applying the classical 4-component SDD, studies remained heterogenic.

Different methods of randomization were used, for example inclusion per time period or per ICU. There was also great variation in the number of patients included in the retrieved trials.

Second, there was great diversity in used prophylactic antimicrobials. In the original design, SDD consisted of locally applied polymyxin E, tobramycin, and amphotericin B plus systemically applied cefotaxim [74]. In one trial locally applied amphotericin B was replaced by nystatin [27]. In other trials tobramyein was replaced by a quinolone [4, 23, 75], gentamicin [66, 76], or neomycin [27, 34]. In many trials, cefotaxim was replaced by another antimicrobial, such as ceftazidime [30], ceftriaxone [77], ciprofloxacin [56, 75], ofloxacin [33], or trimethoprim [4].

Third, criteria for pneumonia were very diverse. Indeed, clinical, radiological, and microbial criteria versus bronchoscopic techniques with quantitative cultures were used. Consequently, the incidence of VAP ranged from as low as less than 10% to as high as 85%. Also, great variation in the mortality of the control group was seen in the different trials, making comparison of studies more difficult.

5. The Effect of SDD on the Incidence of Pneumonia and Mortality

With the exception of 3 trials [25, 28, 31], a reduction of the incidence of pneumonia was seen with the use of SDD (Table 2). Reductions were larger in trials that used more loose criteria for pneumonia. It can be argued that in trials that used only clinical and/or radiologic criteria with or without positive cultures of tracheal secretions the reduction in respiratory tract infections was in fact a reduction in purulent bronchitis and not a reduction in pneumonia per se [3]. All meta-analyses demonstrated a reduction of the incidence of pneumonia with the use of SDD (Table 3).

There were only 2 small studies that demonstrated a reduction of mortality with the use of SDD [4, 5]. Notably, most studies were too small to show a significant effect of SDD on mortality (Table 2). Two recently published well-powered trials also show SDD to reduce mortality of ICU patients [36, 37]. With the exception of 1 meta-analysis [38], reduced mortality rates of ICU patients were seen with the use of SDD (Table 3).

6. Effects of SDD on Microbial Resistance

One concern with prophylactic use of antimicrobial agents is the risk of the emergence of resistant pathogens [78, 79]. Notably, in most trials colonization with resistant bacteria or an increase of superinfections was not reported (Table 4). One trial that specifically addressed the issue of microbial resistance found that resistance rates were actually higher in the control population than in the SDD-treated population [36]. In addition, a reduction in the incidence of multiresistant Klebsiella spp. with SDD use was seen in 3 other trials [65, 80, 81].

However, more recently it was shown that SDD was associated with a gradual increase of rates of ceftazidime-resistant Gram-negative bacteria in the respiratory tract [72]. The rate of resistant Gram-negative bacteria in the gastrointestinal tract significantly increased after discontinuation of SDD [72].

SDD may promote colonization with Gram-positive bacteria. The rate of colonization with Gram-positive strains was significantly higher, and more cases of Gram-positive bacteremia occurred in SDD-treated patients [33, 34].

Two meta-analyses showed that resistance against SDD antimicrobials is not emerging with long-term use [43, 50]. Use of SDD was even associated with a lower rate of colonization as well as infection with resistant Gram-negative bacteria [34, 65, 82].

Additional research is mandatory to determine whether SDD is a safe strategy with respect to the risk of emergence of antimicrobial resistance, especially in countries with higher endemicity of multidrug-resistant pathogens, because with the available evidence this risk cannot completely be denied.

7. Costs of SDD

Several studies compared costs of antimicrobial therapies between the SDD strategy and the control strategy, though in all these trials cost was only a secondary endpoint.

Costs have been calculated in different ways. One trial showed no differences in costs between the SDD strategy and the control strategy [67]. Studies that used cefotaxime showed a reduction of costs. Two other trials, however, showed higher costs with SDD when a quinolone was given for systemic prophylaxis [33, 75].

Four trials analyzed total ICU costs per survivor [5, 61, 77, 83]. These trials showed a reduction of costs with the use of SDD, which was the result of reductions in length of stay and reduced use of systemic antibiotics.

8. Discussion

The findings of our review of the literature can be summarized as follows: (I) numerous trials of SDD show a reduction of the incidence of pneumonia with this preventive strategy, (II) well-powered trials of SDD show a reduction of mortality with SDD, (III) although SDD is associated with induction of antimicrobial resistance in some studies, it certainly was not a problem in all trials, and (IV) SDD seems to be a cost-effective strategy.

Preventive measures against pneumonia in critically ill patients include, but may not be restricted to, early weaning from mechanical ventilation, hand hygiene, aspiration precautions, and prevention of contamination—at times summarized with the acronym “WHAP” [84]. It has been demonstrated that an educational initiative on WHAP, directed at respiratory care practitioners and ICU-nurses, was associated with decreases in VAP incidence rates of up to 61% [84]. One of the problems with the interpretation of the trials of SDD is that it is uncertain whether the caregivers complied with these prevention strategies. Indeed, only “high levels of hygiene” is a component of SDD.

Interpretation and comparison of the results of trials of SDD are complicated by the many dissimilarities amongst SDD regimens that were applied. We tried to solve this issue by focusing on studies that investigated the effect of the classical SDD regimen, applying all 4 components thought to be important for its efficacy [18]. Nevertheless, large differences remained present. Interpretation and comparison of the results of trials of SDD are also complicated by the difference in quality of the individual studies. For instance, large variation in the incidence of pneumonia was seen, due to difference in the way pneumonia was diagnosed. The incidence of pneumonia in studies that used bronchoscopic techniques with quantitative cultures was half of that in studies made the diagnosis of pneumonia on clinical and radiological criteria. Nevertheless, since all studies showed a positive effect of SDD with respect to the rate of pneumonia, we consider the evidence for SDD as an effective prophylactic strategy sufficient. Thereby it can be questioned if it is necessary to give the “full” protocol, with intestinal decontamination and systemic cefotaxime. In the light of the recently published work by de Smet et al. the role of intestinal decontamination and of systemic cefotaxime seems to be questionable [37].

The fast majority of trials of SDD showed no effect on mortality. It should be noted, however, that most studies were underpowered to show any effect on mortality. The last 2 trials of SDD, however, were adequately powered [36, 37]. Since these 2 trials showed SDD to reduce mortality of ICU patients, we also consider the evidence for SDD as a life-saving strategy sufficient.

It can be questioned if SDD should be given to all ICU patients or restricted to selected groups. We have solely focused on the effect of SDD in patients in mixed medical-surgical ICUs.

The emergence of antimicrobial resistance with SDD has been the subject of numerous hot debates [8587]. It has been argued that the use of SDD would promote the growth of resistant bacteria. In theory, this is a potential adverse effect of SDD treatment, but in low antibiotic resistance endemic areas this seems not to be a problem. The 2 trials that investigated resistance were performed in The Netherlands, a country with the lowest use of outpatient antibiotics, generally a narrower spectrum antibiotic for hospitalized patients, a low incidence of methicillin-resistant S. aureus, vancomycin-resistant Enterococci (VRE) other multidrug-resistant pathogens, and extended spectrum bèta-lactamase (ESBL) producing pathogens [88, 89]. This situation is markedly different from other centers across the world.

Because SDD is not active against resistant Gram-positive bacteria, it may promote colonization with bacteria such as S. Aureus, and E. faecalis and it can lead to infections with these bacteria in critically ill patients [9092]. Patients’ illness causes conversion of carriage of normal to abnormal flora. Most ICU patients have bacterial overgrowth. The increased spontaneous mutations lead to polyclonality and antimicrobial resistance [93]. In this way, treatment with SDD could promote gut overgrowth of intrinsically resistant bacteria, such as MRSA and VRE, although with endemicity no increase has been found [36, 94, 95]. However, it cannot be excluded that in countries where VRE is endemic, SDD can have a negative effect on VRE. On the other hand, the reduced prescription of systemic-broad spectrum antibiotics in SDD-treated patients may also lead to decreased incidence of VRE. Although SDD does exert selection pressure on plasmid-mediated ESBL, emergence of ESBL-producing bacteria due to SDD has not been found.

SDD seems a safe strategy with regard to the emergence of antibiotic resistance in low antibiotic resistance endemic areas, but with the available evidence, we cannot say that SDD is also a safe strategy in high endemicity areas. We should consider giving SDD only in low endemic areas till results in high endemic areas are available. Additional research is also mandatory to determine what to do when resistant pathogens do emerge.

Another concern with SDD is the cost associated with this preventive strategy. Costs of SDD have been calculated in several studies, but most of these were not designed to analyze cost-effectiveness. The absence of studies on costs and cost-effectiveness is remarkable. It could be that a proper economic analysis in the ICU setting is difficult to perform, because it is hard to quantify the relative contribution of a single strategy. For example, the price of intravenous antibiotics can vary widely between hospitals, because the price is dependent on negotiations between local pharmacy and manufacturers.

The most important cost component associated with SDD is the cost of antibiotics. As the aim of SDD is to reduce in ICU infections, including pneumonia, a reduction in total antibiotic use can be expected. Overall hospital costs may be lower, in part due to the decrease rate of pneumonia. Development of pneumonia is associated with up to 5 extra days of ICU treatment. Prevention of pneumonia substantially decreases the length of ICU stay and thus reduces costs per patient.

9. Conclusion

Numerous randomized controlled trials have shown that SDD reduces the incidence of pneumonia. Two recently published well-powered trials also show SDD to reduce mortality of ICU patients. SDD can be associated with induction of antimicrobial resistance, but this seems not to be a clinical problem, at least not in countries with low endemicity. Finally, SDD seems to be a cost-effective strategy. Based on these findings, we favor the use of SDD in ICU patients.

References

  1. J. C. Marshall, “Gastrointestinal flora and its alterations in critical illness,” Current Opinion in Clinical Nutrition and Metabolic Care, vol. 2, no. 5, pp. 405–411, 1999. View at Publisher · View at Google Scholar · View at Scopus
  2. G. C. du Moulin, D. G. Paterson, J. Hedley-Whyte, and A. Lisbon, “Aspiration of gastric bacteria in antacid-treated patients: a frequent cause of postoperative colonisation of the airway,” Lancet, vol. 1, no. 8266, pp. 242–245, 1982. View at Google Scholar · View at Scopus
  3. M. J. Schultz, E. de Jonge, and J. Kesecioglu, “Selective decontamination of the digestive tract reduces mortality in critically ill patients,” Critical Care, vol. 7, no. 2, pp. 107–110, 2003. View at Publisher · View at Google Scholar · View at Scopus
  4. C. Ulrich, J. E. Harinck-de Weerd, N. C. Bakker, K. Jacz, L. Doornbos, and V. A. de Ridder, “Selective decontamination of the digestive tract with norfloxacin in the prevention of ICU-acquired infections: a prospective randomized study,” Intensive Care Medicine, vol. 15, no. 7, pp. 424–431, 1989. View at Google Scholar · View at Scopus
  5. L. A. Rocha, M. J. Martin, S. Pita et al., “Prevention of nosocomial infection in critically ill patients by selective decontamination of the digestive tract. A randomized, double blind, placebo-controlled study,” Intensive Care Medicine, vol. 18, no. 7, pp. 398–404, 1992. View at Publisher · View at Google Scholar · View at Scopus
  6. J. P. Burke, “Infection control—a problem for patient safety,” New England Journal of Medicine, vol. 348, no. 7, pp. 651–656, 2003. View at Publisher · View at Google Scholar · View at PubMed · View at Scopus
  7. S. Hugonnet, I. Uçkay, and D. Pittet, “Staffing level: a determinant of late-onset ventilator-associated pneumonia,” Critical Care, vol. 11, no. 4, article R80, 2007. View at Publisher · View at Google Scholar · View at PubMed
  8. J.-L. Vincent, J. Rello, J. Marshall et al., “International study of the prevalence and outcomes of infection in intensive care units,” Journal of the American Medical Association, vol. 302, no. 21, pp. 2323–2329, 2009. View at Publisher · View at Google Scholar · View at PubMed
  9. J.-L. Vincent, “Nosocomial infections in adult intensive-care units,” Lancet, vol. 361, no. 9374, pp. 2068–2077, 2003. View at Publisher · View at Google Scholar · View at PubMed · View at Scopus
  10. D. K. Heyland, D. J. Cook, L. Griffith, S. P. Keenan, and C. Brun-Buisson, “The attributable morbidity and mortality of ventilator-associated pneumonia in the critically ill patient,” American Journal of Respiratory and Critical Care Medicine, vol. 159, no. 4, pp. 1249–1256, 1999. View at Google Scholar
  11. N. Safdar and C. Abad, “Educational interventions for prevention of healthcare-associated infection: a systematic review,” Critical Care Medicine, vol. 36, no. 3, pp. 933–940, 2008. View at Google Scholar · View at Scopus
  12. D. J. Cook, “Ventilator associated pneumonia: perspectives on the burden of illness,” Intensive Care Medicine, vol. 26, no. 1, pp. S31–S37, 2000. View at Google Scholar · View at Scopus
  13. P. Ylipalosaari, T. I. Ala-Kokko, J. Laurila, P. Ohtonen, and H. Syrjälä, “Intensive care unit acquired infection has no impact on long-term survival or quality of life: a prospective cohort study,” Critical Care, vol. 11, no. 2, article R35, 2007. View at Publisher · View at Google Scholar · View at PubMed
  14. N. Safdar, C. Dezfulian, H. R. Collard, and S. Saint, “Clinical and economic consequences of ventilator-associated pneumonia: a systematic review,” Critical Care Medicine, vol. 33, no. 10, pp. 2184–2202, 2005. View at Publisher · View at Google Scholar · View at Scopus
  15. H. K. F. Van Saene, V. Damjanovic, A. E. Murray, and M. A. de la Cal, “How to classify infections in intensive care units—the carrier state, a criterion whose time has come?” Journal of Hospital Infection, vol. 33, no. 1, pp. 1–12, 1996. View at Publisher · View at Google Scholar · View at Scopus
  16. E. M. Leonard, H. K. F. van Saene, P. Shears, J. Walker, and P. K. H. Tam, “Pathogenesis of colonization and infection in a neonatal surgical unit,” Critical Care Medicine, vol. 18, no. 3, pp. 264–269, 1990. View at Google Scholar · View at Scopus
  17. D. van der Waaij, J. M. Berghuis-de Vries, and J. E. van der Lekkerkerk-Wees, “Colonization resistance of the digestive tract in conventional and antibiotic-treated mice,” Journal of Hygiene, vol. 69, no. 3, pp. 405–411, 1971. View at Google Scholar · View at Scopus
  18. D. Th. Sleijfer, N. H. Mulder, H. G. de Vries-Hospers et al., “Infection prevention in granulocytopenic patients by selective decontamination of the digestive tract,” European Journal of Cancer and Clinical Oncology, vol. 16, no. 6, pp. 859–869, 1980. View at Google Scholar · View at Scopus
  19. J. H. Rommes, D. F. Zandstra, and H. K. F. van Saene, “Selective digestive decontamination reduces mortality among intensive care patients,” Nederlands Tijdschrift voor Geneeskunde, vol. 143, no. 12, pp. 602–605, 1999. View at Google Scholar · View at Scopus
  20. I. M. Ledingham, S. R. Alcock, A. T. Eastaway, J. C. McDonald, I. C. McKay, and G. Ramsay, “Triple regimen of selective decontamination of the digestive tract, systemic cefotaxime, and microbiological surveillance for prevention of acquired infection in intensive care,” Lancet, vol. 1, no. 8589, pp. 785–790, 1988. View at Google Scholar
  21. J. Godard, C. Guillaume, M.-E. Reverdy et al., “Intestinal decontamination in a polyvalent ICU. A double-blind study,” Intensive Care Medicine, vol. 16, no. 5, pp. 307–311, 1990. View at Publisher · View at Google Scholar
  22. P. McClelland, A. E. Murray, P. S. Williams et al., “Reducing sepsis in severe combined acute renal and respiratory failure by selective decontamination of the digestive tract,” Critical Care Medicine, vol. 18, no. 9, pp. 935–939, 1990. View at Google Scholar
  23. S. J. A. Aerdts, R. van Dalen, H. A. L. Clasener, J. Festen, H. J. J. van Lier, and E. J. Vollaard, “Antibiotic prophylaxis of respiratory tract infection in mechanically ventilated patients; a prospective, blinded, randomized trial of the effect of a novel regimen,” Chest, vol. 100, no. 3, pp. 783–791, 1991. View at Google Scholar · View at Scopus
  24. P. Blair, B. J. Rowlands, K. Lowry, H. Webb, P. Armstrong, and J. Smilie, “Selective decontamination of the digestive tract: a stratified, randomized, prospective study in a mixed intensive care unit,” Surgery, vol. 110, no. 2, pp. 303–310, 1991. View at Google Scholar
  25. R. G. Finch, P. Romlinson, and M. Holliday, “Selective decontamination of the digestive tract (SDD) in the prevention of secondary sepsis in a medical/surgical intensive care unit,” in Proceedings of the 17th Congress of Chemotherapy, Berlin, Germany, 1991, abstract 471.
  26. P. Gaussorgues, M. Salord, S. Sirodot et al., “Efficiency of selective decontamination of the digestive tract on the occurence of nosocomial bacteremia in patients on mechanical ventilation receiving betamimetic therapy,” Réanimation, Soins Intensifs, Médecine d'Urgence, vol. 7, pp. 169–174, 1991. View at Google Scholar
  27. F. R. Cockerill III, S. R. Muller, J. P. Anhalt et al., “Prevention of infection in critically ill patients by selective decontamination of the digestive tract,” Annals of Internal Medicine, vol. 117, no. 7, pp. 545–553, 1992. View at Google Scholar
  28. J. M. J. Hammond, P. D. Potgieter, G. L. Saunders, and A. A. Forder, “Double-blind study of selective decontamination of the digestive tract in intensive care,” Lancet, vol. 340, no. 8810, pp. 5–9, 1992. View at Publisher · View at Google Scholar
  29. S. Jacobs, J. E. Foweraker, and S. E. Roberts, “Effectiveness of selective decontamination of the digestive tract (SDD) in an ICU with a policy encouraging a low gastric pH,” Clinical Intensive Care, vol. 3, no. 1, pp. 52–58, 1992. View at Google Scholar
  30. R. Winter, H. Humphreys, A. Pick, A. P. MacGowan, S. M. Willatts, and D. C. E. Speller, “A controlled trial of selective decontamination of the digestive tract in intensive care and its effect on nosocomial infection,” Journal of Antimicrobial Chemotherapy, vol. 30, no. 1, pp. 73–87, 1992. View at Google Scholar
  31. M. Ferrer, A. Torres, J. González et al., “Utility of selective digestive decontamination in mechanically ventilated patients,” Annals of Internal Medicine, vol. 120, no. 5, pp. 389–395, 1994. View at Google Scholar
  32. M. Palomar, F. Alvarez-Lerma, R. Jorda, and B. Bermejo, “Prevention of nosocomial infection in mechanically ventilated patients: Selective digestive decontamination versus sucralfate,” Clinical Intensive Care, vol. 8, no. 5, pp. 228–235, 1997. View at Google Scholar
  33. C. Verwaest, J. Verhaegen, P. Ferdinande et al., “Randomized, controlled trial of selective digestive decontamination in 600 mechanically ventilated patients in a multidisciplinary intensive care unit,” Critical Care Medicine, vol. 25, no. 1, pp. 63–71, 1997. View at Publisher · View at Google Scholar
  34. M. Sánchez García, J. A. Cambronero Galache, J. López Diaz et al., “Effectiveness and cost of selective decontamination of the digestive tract in critically III intubated patients: a randomized, double-blind, placebo-controlled, multicenter trial,” American Journal of Respiratory and Critical Care Medicine, vol. 158, no. 3, pp. 908–916, 1998. View at Google Scholar
  35. M. L. Parra Moreno, S. Arias Rivera, M. Á. de La Cal López et al., “Effect of selective digestive decontamination on the nosocomial infection and multiresistant microorganisms incidence in critically ill patients,” Medicina Clinica, vol. 118, no. 10, pp. 361–364, 2002. View at Google Scholar
  36. E. de Jonge, M. J. Schultz, L. Spanjaard et al., “Effects of selective decontamination of digestive tract on mortality and acquisition of resistant bacteria in intensive care: a randomised controlled trial,” Lancet, vol. 362, no. 9389, pp. 1011–1016, 2003. View at Publisher · View at Google Scholar · View at PubMed
  37. A. M. G. A. de Smet, J. A. J. W. Kluytmans, B. S. Cooper et al., “Decontamination of the digestive tract and oropharynx in ICU patients,” New England Journal of Medicine, vol. 360, no. 1, pp. 20–31, 2009. View at Publisher · View at Google Scholar · View at PubMed
  38. C. M. J. E. Vandenbroucke-Grauls and J. P. Vandenbroucke, “Effect of selective decontamination of the digestive tract on respiratory tract infections and mortality in the intensive care unit,” Lancet, vol. 338, no. 8771, pp. 859–862, 1991. View at Google Scholar
  39. S. J. A. Aerdts, H. A. L. Clasener, P. H. B. Blair et al., “Meta-analysis of randomised controlled trials of selective decontamination of the digestive tract. selective decontamination of the digestive tract,” British Medical Journal, vol. 307, no. 6903, pp. 525–532, 1993. View at Google Scholar
  40. D. K. Heyland, D. J. Cook, R. Jaeschke, L. Griffith, H. N. Lee, and G. H. Guyatt, “Selective decontamination of the digestive tract: an overview,” Chest, vol. 105, no. 4, pp. 1221–1229, 1994. View at Google Scholar
  41. M. H. Kollef, “The role of selective digestive tract decontamination on mortality and respiratory tract infections: a meta-analysis,” Chest, vol. 105, no. 4, pp. 1101–1108, 1994. View at Google Scholar
  42. J. C. Hurley, “Prophylaxis with enteral antibiotics in ventilated patients: selective decontamination or selective cross-infection?” Antimicrobial Agents and Chemotherapy, vol. 39, no. 4, pp. 941–947, 1995. View at Google Scholar
  43. R. D'Amico, S. Pifferi, C. Leonetti, V. Torri, A. Tinazzi, and A. Liberati, “Effectiveness of antibiotic prophylaxis in critically ill adult patients: systematic review of randomised controlled trials,” British Medical Journal, vol. 316, no. 7140, pp. 1275–1285, 1998. View at Google Scholar · View at Scopus
  44. A. B. Nathens and J. C. Marshall, “Selective decontamination of the digestive tract in surgical patients: a systematic review of the evidence,” Archives of Surgery, vol. 134, no. 2, pp. 170–176, 1999. View at Publisher · View at Google Scholar
  45. A. Liberati, R. D'Amico, S. Pifferi, and E. Telaro, “Antibiotic prophylaxis in intensive care units: meta-analyses versus clinical practice,” Intensive Care Medicine, vol. 26, no. 1, pp. S38–S44, 2000. View at Google Scholar
  46. R. Redman, E. Ludington, M. Crocker et al., “Analysis of respiratory and non-respiratory infections in published trials of selective digestive decontamination,” Intensive Care Medicine, vol. 27, supplement 1, p. S285, 2001. View at Google Scholar
  47. A. Liberati, R. D'Amico, S. Pifferi, V. Torri, and L. Brazzi, “Antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving intensive care,” Cochrane Database of Systematic Reviews, no. 1, Article ID CD000022, 2004. View at Google Scholar
  48. L. Silvestri, H. K. F. van Saene, M. Milanese, D. Gregori, and A. Gullo, “Selective decontamination of the digestive tract reduces bacterial bloodstream infection and mortality in critically ill patients. Systematic review of randomized, controlled trials,” Journal of Hospital Infection, vol. 65, no. 3, pp. 187–203, 2007. View at Publisher · View at Google Scholar · View at PubMed
  49. L. Silvestri, H. K. F. van Saene, A. Casarin, G. Berlot, and A. Gullo, “Impact of selective decontamination of the digestive tract on carriage and infection due to Gram-negative and Gram-positive bacteria: a systematic review of randomised controlled trials,” Anaesthesia and Intensive Care, vol. 36, no. 3, pp. 324–338, 2008. View at Google Scholar
  50. L. Silvestri, H. K. F. van Saene, I. Weir, and A. Gullo, “Survival benefit of the full selective digestive decontamination regimen,” Journal of Critical Care, vol. 24, no. 3, pp. 474.e7–474.e14, 2009. View at Publisher · View at Google Scholar · View at PubMed
  51. A. Liberati, R. D'Amico, S. Pifferi, V. Torri, and L. Brazzi, “Antibiotic prophylaxis to reduce respiratory tract infections and mortality in adults receiving intensive care,” Cochrane Database of Systematic Reviews, no. 4, Article ID CD000022, 2009. View at Google Scholar
  52. H. Gastinne, “Selective digestive decontamination, effects onepidemiology andbacterial resistances. Practical considerations,” Reanimation, vol. 16, no. 3, pp. 250–255, 2007. View at Publisher · View at Google Scholar
  53. J. Wiener, G. Itokazu, C. Nathan, S. A. Kabins, and R. A. Weinstein, “A randomized, double-blind, placebo-controlled trial of selective digestive decontamination in a medical-surgical intensive care unit,” Clinical Infectious Diseases, vol. 20, no. 4, pp. 861–867, 1995. View at Google Scholar
  54. W. Lingnau, J. Berger, F. Javorsky, M. Fille, F. Allerberger, and H. Benzer, “Changing bacterial ecology during a five year period of selective intestinal decontamination,” Journal of Hospital Infection, vol. 39, no. 3, pp. 195–206, 1998. View at Publisher · View at Google Scholar
  55. M. A. de la Cal, E. Cerdá, H. K. F. van Saene et al., “Effectiveness and safety of enteral vancomycin to control endemicity of methicillin-resistant Staphylococcus aureus in a medical/surgical intensive care unit,” Journal of Hospital Infection, vol. 56, no. 3, pp. 175–183, 2004. View at Publisher · View at Google Scholar · View at PubMed
  56. W. A. Krueger, F.-P. Lenhart, G. Neeser et al., “Influence of combined intravenous and topical antibiotic prophylaxis on the incidence of infections, organ dysfunctions, and mortality in critically III surgical patients: a prospective, stratified, randomized, double-blind, placebo-controlled clinical trial,” American Journal of Respiratory and Critical Care Medicine, vol. 166, no. 8, pp. 1029–1037, 2002. View at Publisher · View at Google Scholar
  57. A. Heininger, E. Meyer, F. Schwab, M. Marschal, K. Unertl, and W. A. Krueger, “Effects of long-term routine use of selective digestive decontamination on antimicrobial resistance,” Intensive Care Medicine, vol. 32, no. 10, pp. 1569–1576, 2006. View at Publisher · View at Google Scholar · View at PubMed
  58. P. M. Arnow, G. C. Carandang, R. Zabner, and M. E. Irwin, “Randomized controlled trial of selective bowel decontamination for prevention of infections following liver transplantation,” Clinical Infectious Diseases, vol. 22, no. 6, pp. 997–1003, 1996. View at Google Scholar
  59. W. C. Hellinger, J. D. Yao, S. Alvarez et al., “A randomized, prospective, double-blinded evaluation of selective bowel decontamination in liver transplantation,” Transplantation, vol. 73, no. 12, pp. 1904–1909, 2002. View at Google Scholar
  60. D. C. J. J. Bergmans, M. J. M. Bonten, C. A. Gaillard et al., “Prevention of ventilator-associated pneumonia by oral decontamination: a prospective, randomized, double-blind, placebo-controlled study,” American Journal of Respiratory and Critical Care Medicine, vol. 164, no. 3, pp. 382–388, 2001. View at Google Scholar
  61. A. M. Korinek, M. J. Laisne, M. H. Nicolas, L. Raskine, V. Deroin, and M. J. Sanson-Lepors, “Selective decontamination of the digestive tract in neurosurgical intensive care unit patients: a double-blind, randomized, placebo-controlled study,” Critical Care Medicine, vol. 21, no. 10, pp. 1466–1473, 1993. View at Google Scholar
  62. A. M. Korinek, “Ecological impact of preventive antibiotherapy,” Annales Francaises d'Anesthesie et de Reanimation, vol. 19, no. 5, pp. 418–423, 2000. View at Google Scholar
  63. J. Pugin, R. Auckenthaler, D. P. Lew, and P. M. Suter, “Oropharyngeal decontamination decreases incidence of ventilator-associated pneumonia: a randomized, placebo-controlled, double-blind clinical trial,” Journal of the American Medical Association, vol. 265, no. 20, pp. 2704–2710, 1991. View at Publisher · View at Google Scholar
  64. H. M. Schardey, U. Joosten, U. Finks et al., “The prevention of anastomotic leakage after total gastrectomy with local decontamination: a prospective, randomized, double-blind, placebo-controlled multicenter trial,” Annals of Surgery, vol. 225, no. 2, pp. 172–180, 1997. View at Publisher · View at Google Scholar
  65. C. Brun-Buisson, P. Legrand, A. Rauss et al., “Intestinal decontamination for control of nosocomial multiresistant gram-negative bacilli. Study of an outbreak in an intensive care unit,” Annals of Internal Medicine, vol. 110, no. 11, pp. 873–881, 1989. View at Google Scholar
  66. K. Unertl, G. Ruckdeschel, H. K. Selbmann et al., “Prevention of colonization and respiratory infections in long-term ventilated patients by local antimicrobial prophylaxis,” Intensive Care Medicine, vol. 13, no. 2, pp. 106–113, 1987. View at Google Scholar
  67. P. H. J. van der Voort, E. N. van Roon, G. A. Kampinga et al., “A before-after study of multi-resistance and cost of selective decontamination of the digestive tract,” Infection, vol. 32, no. 5, pp. 271–277, 2004. View at Publisher · View at Google Scholar
  68. M. Leone, J. Albanese, F. Antonini, A. Nguyen-Michel, and C. Martin, “Long-term (6-year) effect of selective digestive decontamination on antimicrobial resistance in intensive care, multiple-trauma patients,” Critical Care Medicine, vol. 31, no. 8, pp. 2090–2095, 2003. View at Publisher · View at Google Scholar · View at PubMed
  69. G. L. Saunders, J. M. J. Hammond, P. D. Potgieter, H. A. Plumb, and A. A. Forder, “Microbiological surveillance during selective decontamination of the digestive tract (SDD),” Journal of Antimicrobial Chemotherapy, vol. 34, no. 4, pp. 529–544, 1994. View at Google Scholar
  70. W. A. Krueger, A. Heininger, and K. E. Unertl, “Selective digestive tract decontamination in intensive care medicine. Fundamentals and current evaluation,” Anaesthesist, vol. 52, no. 2, pp. 142–152, 2003. View at Publisher · View at Google Scholar · View at PubMed
  71. L. A. Rocha, M. J. Martin, S. Pita et al., “Prevention of nosocomial infection in critically ill patients by selective decontamination of the digestive tract. A randomized, double blind, placebo-controlled study,” Intensive Care Medicine, vol. 18, no. 7, pp. 398–404, 1992. View at Publisher · View at Google Scholar
  72. E. A. N. Oostdijk, A. M. G. A. de Smet, H. E. M. Blok et al., “Ecological effects of selective decontamination on resistant gram-negative bacterial colonization,” American Journal of Respiratory and Critical Care Medicine, vol. 181, no. 5, pp. 452–457, 2010. View at Publisher · View at Google Scholar · View at PubMed
  73. J. M. J. Hammond and P. D. Potgieter, “Long-term effects of selective decontamination on antimicrobial resistance,” Critical Care Medicine, vol. 23, no. 4, pp. 637–645, 1995. View at Google Scholar
  74. C. P. Stoutenbeek, H. K. F. van Saene, D. R. Miranda, and D. F. Zandstra, “A new technique of infection prevention in the intensive care unit by selective decontamination of the digestive tract,” Acta Anaesthesiologica Belgica, vol. 34, no. 3, pp. 209–221, 1983. View at Google Scholar
  75. W. Lingnau, J. Berger, F. Javorsky, P. Lejeune, N. Mutz, and H. Benzer, “Selective intestinal decontamination in multiple trauma patients: prospective, controlled trial,” Journal of Trauma, vol. 42, no. 4, pp. 687–694, 1997. View at Google Scholar
  76. J. Flaherty, C. Nathan, S. A. Kabins, and R. A. Weinstein, “Pilot trial of selective decontamination for prevention of bacterial infection in an intensive care unit,” Journal of Infectious Diseases, vol. 162, no. 6, pp. 1393–1397, 1990. View at Google Scholar
  77. M. Sánchez García, J. A. Cambronero Galache, J. López Diaz et al., “Effectiveness and cost of selective decontamination of the digestive tract in critically III intubated patients: a randomized, double-blind, placebo-controlled, multicenter trial,” American Journal of Respiratory and Critical Care Medicine, vol. 158, no. 3, pp. 908–916, 1998. View at Google Scholar
  78. C. D. Salgado, N. O'Grady, and B. M. Farr, “Prevention and control of antimicrobial-resistant infections in intensive care patients,” Critical Care Medicine, vol. 33, no. 10, pp. 2373–2382, 2005. View at Publisher · View at Google Scholar
  79. A. J. Bastin and K. B. Ryanna, “Use of selective decontamination of the digestive tract in United Kingdom intensive care units,” Anaesthesia, vol. 64, no. 1, pp. 46–49, 2009. View at Publisher · View at Google Scholar · View at PubMed
  80. M. E. Taylor and B. A. Oppenheim, “Selective decontamination of the gastrointestinal tract as an infection control measure,” Journal of Hospital Infection, vol. 17, no. 4, pp. 271–278, 1991. View at Publisher · View at Google Scholar
  81. C. Brun-Buisson and H. K. F. van Saene, “SDD and the novel extended-broad-spectrum β-lactamases,” Journal of Antimicrobial Chemotherapy, vol. 28, no. 1, pp. 145–147, 1991. View at Google Scholar
  82. E. de Jonge, “Effects of selective decontamination of digestive tract on mortality and antibiotic resistance in the intensive-care unit,” Current Opinion in Critical Care, vol. 11, no. 2, pp. 144–149, 2005. View at Publisher · View at Google Scholar
  83. C. P. Stoutenbeek, H. K. F. Saene, and D. F. Zandstra, “Prevention of multiple organ system failure by selective decontamination of the digestive tract in multiple trauma patients,” in The Immune Consequences of Trauma, Shock and Sepsis, E. Faist, A. E. Baue, and F. W. Schildberg, Eds., pp. 1055–1066, Pabst Science, Lengerich, Germany, 1996. View at Google Scholar
  84. H. M. Babcock, J. E. Zack, T. Garrison et al., “An educational intervention to reduce ventilator-associated pneumonia in an integrated health system: a comparison of effects,” Chest, vol. 125, no. 6, pp. 2224–2231, 2004. View at Publisher · View at Google Scholar
  85. M. J. M. Bonten and W. A. Krueger, “Selective decontamination of the digestive tract: cumulating evidence, at last?” Seminars in Respiratory and Critical Care Medicine, vol. 27, no. 1, pp. 18–22, 2006. View at Google Scholar
  86. L. Silvestri and H. K. F. van Saene, “Selective decontamination of the digestive tract does not increase resistance in critically ill patients: evidence from randomized controlled trials,” Critical Care Medicine, vol. 34, no. 7, pp. 2027–2030, 2006. View at Publisher · View at Google Scholar · View at PubMed
  87. R. G. Wunderink, “Welkommen to our world: emergence of antibiotic resistance with selective decontamination of the digestive tract,” American Journal of Respiratory and Critical Care Medicine, vol. 181, no. 5, pp. 426–427, 2010. View at Publisher · View at Google Scholar · View at PubMed
  88. H. Goossens, M. Ferech, R. Vander Stichele et al., “Outpatient antibiotic use in Europe and association with resistance: a cross-national database study,” Lancet, vol. 365, no. 9459, pp. 579–587, 2005. View at Publisher · View at Google Scholar · View at PubMed
  89. R. Cantón, A. Novais, A. Valverde et al., “Prevalence and spread of extended-spectrum β-lactamase-producing Enterobacteriaceae in Europe,” Clinical Microbiology and Infection, vol. 14, no. 1, pp. 144–153, 2008. View at Publisher · View at Google Scholar · View at PubMed
  90. A. Kaufhold, W. Behrendt, T. Krauss, and H. van Saene, “Selective decontamination of the digestive tract and methicillin-resistant Staphylococcus aureus,” Lancet, vol. 339, no. 8806, pp. 1411–1412, 1992. View at Publisher · View at Google Scholar
  91. M. J. M. Bonten, C. A. Gaillard, F. H. van Tiel, S. van der Geest, and E. E. Stobberingh, “Colonization and infection with Enterococcus faecalis in intensive care units: the role of antimicrobial agents,” Antimicrobial Agents and Chemotherapy, vol. 39, no. 12, pp. 2783–2786, 1995. View at Google Scholar
  92. Y. W. J. Sijpkens, E. J. Buurke, C. Ulrich, and G. J. van Asselt, “Enterococcus faecalis colonisation and endocarditis in five intensive care patients as late sequelae of selective decontamination,” Intensive Care Medicine, vol. 21, no. 3, pp. 231–234, 1995. View at Publisher · View at Google Scholar
  93. V. Damjanovic and H. K. F. van Saene, “Microbial mutation as a source of polyclonality in the gut of the critically ill,” Journal of Hospital Infection, vol. 59, no. 4, pp. 374–375, 2005. View at Publisher · View at Google Scholar · View at PubMed
  94. W. A. Krueger, “Selective digestive decontamination,” Journal fur Anasthesie und Intensivbehandlung, vol. 11, no. 1, pp. 153–154, 2004. View at Google Scholar
  95. A. Heininger, E. Meyer, F. Schwab, M. Marschal, K. Unertl, and W. A. Krueger, “Effects of long-term routine use of selective digestive decontamination on antimicrobial resistance,” Intensive Care Medicine, vol. 32, no. 10, pp. 1569–1576, 2006. View at Publisher · View at Google Scholar · View at PubMed