Infection Control & Hospital Epidemiology
139
Fig. 7. Appraisal of quality of study methodology of all included randomized control trials (RCTs).
1981 and 2006. However, we did not observe a statistically sig- nificant change in the proportion of postoperative infections among patients who received currently recommended antibiotic prophylaxis in RCTs for appendectomy, cesarean section, or TRPB. To our knowledge, there are no previous reports on temporal trends of the efficacy of currently recommended anti- biotic prophylaxis agents for various surgical procedures. Among the 4 procedures, colorectal surgery had the highest (14%) and TRPB had the lowest (1.2%) pooled postoperative infection proportion. Our findings for colorectal surgery are robust; the trends
remained significant even after adjusting for the type of surgery and antibiotics used and after excluding the last RCT conducted in 2005, which showed high SSI rate (Supplementary Table 4). The results remained significant in a subanalysis of 22 RCTs that had prophylactic antibiotic administration within 60 minutes or at the time of anesthesia induction, had patient follow-up of at least 4 weeks, and included surgical incision and organ space infections. The main group of pathogens associated with SSIs following colorectal surgery include mixed aerobic and anaerobic bacteria including Enterobacteriaceae and Bacteroides spp, most of which originate from the patient’s own intestinal microbiota.90 The reduction in efficacy could be explained by the rise in intestinal colonization of antibiotic-resistant Enterobacteriaceae and Bacteroides spp. A recent meta-analysis reported a significant increase in the burden of extended-spectrum β-lactamase–pro- ducing Enterobacteriaceae (ESBL-PE) among healthy individuals worldwide, with an annual rate of ~5%.91 Similarly, reported increasing rates of cefoxitin- and cefotetan-resistant Bacteroides spp have been reported. In Europe, the cefoxitin-resistant Bacteroides fragilis group increased from 3.2% in 1988–1989 to 17.2% in 2008–2009.92 In United States between 1990 and 1996, cefotetan-resistance among Bacteroides spp increased annually by 5%.93 Our findings are also consistent with the results of an RCT
that demonstrated superior efficacy of ertapenem over cefotetan (the currently recommended prophylaxis agent) in preventing SSIs following colorectal surgery. In this study, the proportion of SSIs in the ertapenem group was significantly lower (18% vs 31%; absolute difference = −13%; 95% CI, −19.5 to −6.5) compared with the cefotetan group.45 Ertapenem is a broad-spectrum antibiotic with activity against ESBL-PE that has superior activity against anaerobic bacteria including Bacteroides spp.94 In this RCT,45 the anaerobic bacteria and gram-negative bacilli isolated from SSIs were less resistant to ertapenem than cefotetan, indi- cating the superior efficacy of ertapenem.
For patients who underwent appendectomy due to simple appendicitis, we did not observe a significant change in the trend in the proportion of SSIs using the current recommended anti- biotic prophylaxis agents (cefotetan, cefoxitin, or cefazolin plus metronidazole). Although the predominant pathogens associated with SSIs following appendectomy are similar to those following colorectal surgery, there has been no significant change in SSI trends. Some possible explanations include the small number of RCTs, the fact that it is a relatively clean procedure with less contamination of the operative area than with colorectal surgery, and the low postoperative SSI rate (3% for appendectomy vs 14% for colorectal surgery). As with appendectomy, we did not observe a significant
change in SSI trends following cesarean sections. The most common pathogens associated with SSIs following cesarean sec- tion include Staphylococcus aureus, E. coli, and coagulase negative staphylococci.95 Methicillin-resistant S. aureus (MRSA) and ESBL-PE are resistant to first-generation cephalosporins includ- ing cefazolin. However, the low SSI rate (pooled proportion of SSI=4.1%) following cesarean section could be a reason for not finding a significant change, as studies with large numbers of patients are required to observe a significant change in the trend. Among patients who underwent TRPB included in 15 RCTs
conducted between 1991 and 2016, we did not observe a sig- nificant change in trends in the proportion of postprocedural infections (UTIs and sepsis) using the current recommended antibiotic prophylaxis agents, fluoroquinolones. Esherichia coli is the most common pathogen associated with infections following TRPB. Although several recent studies, including a meta-analysis of 9 prospective cohort studies,96 reported an increased risk of infections following TRPB among patients colonized with fluoroquinolone-resistant Enterobacteriaceae, we did not observe a significant change in the proportion of infections over time in our study despite the increasing prevalence of ESBL-PE among healthy carriers worldwide.91 Possible explanation for this finding include very low infection rate following TRPB (pooled propor- tion of infections following TRPB=1.2%) and an insufficient number of RCTs. This review has several limitations. First, heterogeneity among
studies in terms of the nature of SSI surveillance, duration of surgery, case mix of patients, infection control practices, appro- priate timing of antibiotics, dosage of antibiotics, and types of surgeries performed may have influenced the overall infection rates. However, we used random-effects models to estimate the pooled proportion of infections, and the rising trend of SSIs observed after colorectal surgery was robust in several sensitivity
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156
