[Duration of the preventive use of antibiotics in colorectal surgery--single administration versus short-term prevention]

Antibiotics for preventing infection at the surgical site: Single dose vs. multiple doses

Background

Surgical site infections are common and expensive infections that can cause fatalities or poor patient outcomes. To prevent these infections, antibiotic prophylaxis is used. However, excessive antibiotic use is related to higher costs and the emergence of antimicrobial resistance.

Objectives

The present meta-analysis aimed to compare the effectiveness of a single dosage versus several doses of antibiotics in preventing the development of surgical site infections.

Methods

PubMed was used to find clinical trials evaluating the effectiveness of a single dosage versus several doses of antibiotics in avoiding the development of surgical site infections. The study included trials that were published between 1984 and 2022. Seventy-four clinical trials were included in the analysis. Odds ratios were used to compare groups with 95% confidence intervals. The data were displayed using OR to generate a forest plot. Review Manager (RevMan version 5.4) was used to do the meta-analysis.

Results

Regarding clean operations, there were 389 surgical site infections out of 5,634 patients in a single dose group (6.90%) and 349 surgical site infections out of 5,621 patients in multiple doses group (6.21%) (OR = 1.11, lower CI = 0.95, upper CI = 1.30). Regarding clean-contaminated operations, there were 137 surgical site infections out of 2,715 patients in a single dose group (5.05%) and 137 surgical site infections out of 2,355 patients in multiple doses group (5.82%) (OR = 0.87, lower CI = 0.68, upper CI = 1.11). Regarding contaminated operations, there were 302 surgical site infections out of 3,262 patients in a single dose group (9.26%) and 276 surgical site infections out of 3,212 patients in multiple doses group (8.59%) (OR = 1.11, lower CI = 0.84, upper CI = 1.47). In general, there were 828 surgical site infections out of 11,611 patients in a single dose group (7.13%) and 762 surgical site infections out of 11,188 patients in multiple doses group (6.81%) (OR = 1.05, lower CI = 0.93, upper CI = 1.20). The difference between groups was not significant.

Conclusion

The present study showed that using a single-dose antimicrobial prophylaxis was equally effective as using multiple doses of antibiotics in decreasing surgical site infections.

Antimicrobial prophylaxis for colorectal surgery

BACKGROUND

Research shows that administration of prophylactic antibiotics before colorectal surgery prevents postoperative surgical wound infection. The best antibiotic choice, timing of administration and route of administration remain undetermined.

OBJECTIVES

To establish the effectiveness of antimicrobial prophylaxis for the prevention of surgical wound infection in patients undergoing colorectal surgery. Specifically to determine:1. whether antimicrobial prophylaxis reduces the risk of surgical wound infection;2. the target spectrum of bacteria (aerobic or anaerobic bacteria, or both);3. the best timing and duration of antibiotic administration;4. the most effective route of antibiotic administration (intravenous, oral or both);5. whether any antibiotic is clearly more effective than the currently recommended gold standard specified in published guidelines;6. whether antibiotics should be given before or after surgery.

SEARCH METHODS

For the original review published in 2009 we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE (Ovid) and EMBASE (Ovid). For the update of this review we rewrote the search strategies and extended the search to cover from 1954 for MEDLINE and 1974 for EMBASE up to 7 January 2013. We searched CENTRAL on the same date (Issue 12, 2012).

SELECTION CRITERIA

Randomised controlled trials of prophylactic antibiotic use in elective and emergency colorectal surgery, with surgical wound infection as an outcome.

DATA COLLECTION AND ANALYSIS

Data were abstracted and reviewed by one review author and checked by another only for the single, dichotomous outcome of surgical wound infection. Quality of evidence was assessed using GRADE methods.

MAIN RESULTS

This updated review includes 260 trials and 68 different antibiotics, including 24 cephalosporins and 43,451 participants. Many studies had multiple variables that separated the two study groups; these could not be compared to other studies that tested one antibiotic and had a single variable separating the two groups. We did not consider the risk of bias arising from attrition and lack of blinding of outcome assessors to affect the results for surgical wound infection.Meta-analyses demonstrated a statistically significant difference in postoperative surgical wound infection when prophylactic antibiotics were compared to placebo/no treatment (risk ratio (RR) 0.34, 95% confidence interval (CI) 0.28 to 0.41, high quality evidence). This translates to a reduction in risk from 39% to 13% with prophylactic antibiotics. The slightly higher risk of wound infection with short-term compared with long-term duration antibiotic did not reach statistical significance (RR 1.10, 95% CI 0.93 to 1.30). Similarly risk of would infection was slightly higher with single-dose antibiotics when compared with multiple dose antibiotics, but the results are compatible with benefit and harm (RR 1.30, 95% CI 0.81 to 2.10). Additional aerobic coverage and additional anaerobic coverage both showed statistically significant improvements in surgical wound infection rates (RR 0.44, 95% CI 0.29 to 0.68 and RR 0.47, 95% CI 0.31 to 0.71, respectively), as did combined oral and intravenous antibiotic prophylaxis when compared to intravenous alone (RR 0.56, 95% CI 0.43 to 0.74), or oral alone (RR 0.56, 95% CI 0.40 to 0.76). Comparison of an antibiotic with anaerobic specificity to one with aerobic specificity showed no significant advantage for either one (RR 0.84, 95% CI 0.30 to 2.36). Two small studies compared giving antibiotics before or after surgery and no significant difference in this timing was found (RR 0.67, 95% CI 0.21 to 2.15). Established gold-standard regimens recommended in major guidelines were no less effective than any other antibiotic choice.

AUTHORS' CONCLUSIONS

This review has found high quality evidence that antibiotics covering aerobic and anaerobic bacteria delivered orally or intravenously (or both) prior to elective colorectal surgery reduce the risk of surgical wound infection. Our review shows that antibiotics delivered within this framework can reduce the risk of postoperative surgical wound infection by as much as 75%. It is not known whether oral antibiotics would still have these effects when the colon is not empty. This aspect of antibiotic dosing has not been tested. Further research is required to establish the optimal timing and duration of dosing, and the frequency of longer-term adverse effects such as Clostridium difficile pseudomembranous colitis.

Antimicrobial prophylaxis for colorectal surgery

BACKGROUND

Research shows that administration of prophylactic antibiotics before colorectal surgery prevents postoperative surgical wound infection (SWI). The best antibiotic choice, timing of administration and route of administration remain undetermined.

OBJECTIVES

To establish the effectiveness of antimicrobial prophylaxis for the prevention of SWI in patients undergoing colorectal surgery: specifically to determine, 1 Whether it reduces risk of SWI. 2 The target spectrum/a of bacteria (aerobic and/or anaerobic). 3 The best timing and duration of antibiotic administration. 4 The most effective route of antibiotic administration (intravenous, oral or both). 5 Whether any antibiotic is clearly more effective than the currently recommended gold standard.

SEARCH STRATEGY

CENTRAL, MEDLINE, and EMBASE, were searched from January, 1980 to December, 2007.

SELECTION CRITERIA

Randomised controlled trials of prophylactic antibiotic use in elective and emergency colorectal surgery, with SWI as an outcome.

DATA COLLECTION AND ANALYSIS

Data were abstracted and reviewed by three authors for only the single, dichotomous outcome of SWI.

MAIN RESULTS

The review included 182 trials (30,880 participants), and 50 different antibiotics, including 17 cephalosporins. Many studies had multiple variables that separated the two study groups and could not be compared to other studies that tested one antibiotic and had a single variable separating the two groups. Meta-analyses demonstrated a statistically significant difference in postoperative SWI when prophylactic antibiotics were compared to placebo/no treatment (relative risk (RR) 0.30, 95% confidence intervals (CI) 0.22 to 0.41). No statistically significant differences were shown when comparing short- and long-term duration of prophylaxis (RR 1.06, 95% CI 0.89 to 1.27); or single dose versus multiple dose antibiotics (RR 1.17, 95% CI 0.67 to 2.05). Additional aerobic coverage and additional anaerobic coverage both showed statistically significant improvements in SWI rates (RR 0.41, 95% CI 0.23 to 0.71 and RR 0.55, 95% CI 0.35 to 0.85, respectively); as did combined oral and intravenous antibiotic prophylaxis when compared to intravenous alone (RR 0.55, 95% CI 0.41 to 0.74), or oral alone (RR 0.34, 95% CI 0.13 to 0.87). Established gold standard regimens were no less effective than any other antibiotic choice.

AUTHORS' CONCLUSIONS

Antibiotics covering aerobic and aerobic bacteria should be delivered orally and intravenously prior to colorectal surgery. Antibiotics delivered within this framework will reduce the risk of postoperative SWI by at least 75%. Further research is required to establish the optimal timing and duration of dosing, and frequency of longer-term adverse effects such as Clostridium difficile pseudomembranous colitis.

Antimicrobial prophylaxis for abdominal surgery: is there a need for metronidazole?

The objective of the present multicenter observational study was to assess postoperative infections as a function of risk factors and antibiotic prophylaxis under everyday clinical conditions. 2513 patients from 114 centers in Germany who received infection prophylaxis prior to elective colonic resection were included in the study between 1st September 1996 and 30th September 1997. In the descriptive analysis of the study it was noted that 36.1% of the patients had received no prophylaxis with metronidazole despite the fact that the study protocol recommended the use of this drug in preoperative antibiotic combinations. The present analysis therefore considers the influence of metronidazole on the postoperative infection rate. To exclude any bias due to intergroup differences in risk profile, the groups with and without metronidazole were subjected to a matched-pair analysis. Matching parameters were: duration of operation, blood loss, age, diabetes mellitus, hepatic, renal, or chronic airways disease, immunosuppressive therapy, and rectal resection. This led to the formation of 800 pairs that were matched with respect to these parameters. The 800 pairs were then stratified into the following treatment groups: Group 1: long-acting cephalosporin (ceftriaxone) with or without metronidazole (n = 2 x 491); Group 2: short-acting cephalosporins with or without metronidazole (n = 2 x 133); Group 3: broad-spectrum penicillins with or without metronidazole (n = 2 x 176). In all three treatment groups combination therapy with metronidazole was found to be significantly superior. Postoperative infection rates with and without metronidazole were 9.4% and 18.7% respectively in Group 1, 12.0% and 25.6% respectively in Group 2, and 19.9% and 29.0% respectively in Group 3. The lowest infection rate was thus achieved by means of preoperative infection prophylaxis with ceftriaxone plus metronidazole. Thus, preoperative administration of metronidazole in addition to a long-acting beta-lactam antibiotic is strongly advised in elective colon surgery, as absence of antibiotic cover against anaerobic colonic flora leads to a significantly higher postoperative infection rate.

Antimicrobial prophylaxis in colorectal surgery: a systematic review of randomized controlled trials

BACKGROUND

A systematic review was carried out to assess the relative efficacy of antimicrobial prophylaxis for the prevention of postoperative wound infection in patients undergoing colorectal surgery.

METHODS

MEDLINE, EMBASE, the Cochrane Trials Register and the references cited in retrieved studies were searched to identify relevant trials published between 1984 and 1995.

RESULTS

Some 147 relevant trials were identified. The quality of trials has improved over the past 12 years. The results confirm that the use of antimicrobial prophylaxis is effective for the prevention of surgical wound infection after colorectal surgery. There was no significant difference in the rate of surgical wound infections between many different regimens. However, certain regimens appear to be inadequate (e.g. metronidazole alone, doxycycline alone, piperacillin alone, oral neomycin plus erythromycin on the day before operation). A single dose administered immediately before the operation (or short-term use) is as effective as long-term postoperative antimicrobial prophylaxis (odds ratio 1.17 (95 per cent confidence interval (c.i.) 0.90-1.53)). There is no convincing evidence to suggest that the new-generation cephalosporins are more effective than first-generation cephalosporins (odds ratio 1.07 (95 per cent c.i. 0.54-2.12)).

CONCLUSION

Antibiotics selected for prophylaxis in colorectal surgery should be active against both aerobic and anaerobic bacteria. Administration should be timed to make sure that the tissue concentration of antibiotics around the wound area is sufficiently high when bacterial contamination occurs. Guidelines should be developed locally in order to achieve a more cost-effective use of antimicrobial prophylaxis in colorectal surgery.

[Etiology and consequences of postoperative wound infection]

The incidence of postoperative wound infection ranges between 4.6% and 36% after gastrointestinal operations respectively. To evaluate the factors which influence the postoperative wound infection we prospectively analyzed our patients between 1/1989 and 1/1990. 444 patients from three general surgical units of our clinic entered this study. The overall wound infection rate was 6.3%. We classified the patients into 3 operative groups: Group I: subcutaneous operations; Group II: intraabdominal operations without opening the GI-tract; Group III: gastrointestinal operations. Wound infection rate in group I was 1.8%, in group II 7.3% and in group III 13.7%. The differences were highly significant. Both univariate (chi 2-test) as well as a multivariate (Cox-Model) analysis were done. We figured out that classification of patients (p = 0.000), operation time (p = 0.009), operating room (p = 0.000), intensive care unit (p = 0.026), long-term antibiotic prophylaxis (p = 0.001), subcutaneous haematoma (p = 0.000) and length of closed drainage time (p = 0.001) are of significant value. In the Cox model the classification of patients into 3 groups surpassed all the other factors. Postoperative hospital stay was lengthened in patients with wound infection significantly (p = 0.0025).