Comparison of prophylactic ampicillin/sulbactam with gentamicin and metronidazole in elective colorectal surgery: a randomized clinical study

Comparison of Cefazolin/Metronidazole to Ampicillin/Sulbactam as Preoperative Antibiotics in Colorectal Surgery: A Retrospective, Single-Center Cohort Study

AIM

The use of prophylactic antibiotics prior to colorectal surgery reduces surgical site infections. Cefazolin and metronidazole are used as a standard regimen. Ampicillin/sulbactam may be an alternative, but current data are limited. We compared the efficacy of ampicillin/sulbactam with cefazolin and metronidazole as prophylactic antibiotics.

METHODS

Patients who underwent colorectal surgery at Inha University Hospital between 2010 and 2020 were treated prophylactically with cefazolin and metronidazole or ampicillin/sulbactam, and observed for 30 days following surgery. The primary outcome was surgical site infections. The secondary outcomes were deep/organ infections and the need for drainage.

RESULTS

SSIs occurred in 2.6% (17/646) of the ampicillin/sulbactam group, whose rate was not inferior to the occurrence in the group receiving cefazolin and metronidazole (3.8%, 21/556). There was no significant difference between the two groups in the secondary outcomes.

CONCLUSIONS

Compared to the cefazolin and metronidazole combination, ampicillin/sulbactam is not inferior as a preoperative prophylactic antibiotic regimen for colorectal surgery.

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.

Dosis única preoperatoria de metronidazol más gentamicina para profilaxis antibiótica en cirugía colorrectal

BACKGROUND AND OBJECTIVE

To prove that a single-preoperative dose (SD) of metronidazole plus gentamicin guarantees the same clinical effectiveness than the same dose administered in a multiple-perioperative schedule (MD), with a reduction of the direct costs.

PATIENTS AND METHOD

A retrospective cohort study with patients undergoing elective colorectal surgery between 1995 and 2003 was designed. Patients in the cohort of cases received a SD of metronidazole 1500 mg plus gentamicin 240 mg between 1999 and 2003. Patients included in the cohort of controls received the same dose of antibiotics in a MD schedule between 1995 and 1997. Clinical effectiveness was evaluated as length of stay, mortality and rate of surgical-related infections. Economic analysis was performed using direct costs of therapy exclusively.

RESULTS

414 patients were included in the cohort of MD and 978 were included in the cohort of SD. Total length of stay (standard deviation) was 15.1 (16.2 days), with a significant reduction in the SD cohort versus the MD cohort: 14.0 (15.4) days versus 17.5 (17.8) days (p < 0.001). No differences in mortality (overall rate 3.2%) or surgical infection rate (overall rate 8.6%) between cohorts were found. SD schedule produces a 35% cost-reduction per procedure.

CONCLUSIONS

Attending the clinical effectiveness, no differences between SD and MD cohorts were found. Therefore, according to logistics advantages and costs reduction, the SD of antibiotic is considered the most efficient option.

New perspectives in antibiotic prophylaxis for intra-abdominal surgery

Effective management of intra-abdominal infections requires a combination of preoperative preparation, antibiotic prophylaxis and appropriate surgical technique. Antibacterial prophylaxis should provide coverage of all likely pathogens, including aerobic and anaerobic organisms. Whereas antibacterial combination therapy is appropriate in certain situations, single-agent prophylaxis is appropriate for the majority of patients and ampicillin/sulbactam, with its broad-spectrum anti-aerobic/anti-anaerobic activity, is an attractive prophylactic option. Surgery involving the gastrointestinal tract provides a special challenge by virtue of its high, predominantly anaerobic, bacterial load. However, the requirement for prophylaxis varies depending upon the precise site of intervention. Biliary tract surgery requires prophylaxis in high-risk patients only, whereas hepatobiliary or pancreatic surgery requires prophylaxis in all patients. Gastroduodenal operations require prophylaxis in the presence of risk factors, such as abnormal gastric acidity or bleeding. Colorectal procedures present a high risk of anaerobic infection and sepsis, and require adequate prophylaxis combined with a thorough preoperative preparation designed to reduce considerably the bacterial load of the bowel. Where peritonitis does follow intra-abdominal surgery, patients should receive antibacterial therapy commensurate with the risk of serious infection. A small proportion of patients will be at risk of severe infection and will require triple-agent therapy. However, most patients are likely to develop mild-to-moderate infections only and can be treated with a single, broad-spectrum antibiotic agent, such as ampicillin/sulbactam, a beta-lactam/beta-lactamase inhibitor.

Efficacy and cost of ampicillin-sulbactam and ticarcillin-clavulanate in the treatment of hospitalized patients with bacterial infections

STUDY OBJECTIVE

To evaluate the efficacy and cost of treatment with two beta-lactam/beta-lactamase-inhibitor combinations.

DESIGN

Retrospective, open-label multicenter study.

SETTING

Fifty-four hospitals across the United States.

PATIENTS

Eight hundred ninety patients with skin and soft tissue, intraabdominal, gynecologic, respiratory, urinary tract, or other infections that required parenteral antibiotic therapy.

INTERVENTION

Patients were administered either ampicillin-sulbactam 1.5 or 3.0 g every 6 hours or ticarcillin-clavulanate 3.1 g every 6 hours.

MEASUREMENTS AND MAIN RESULTS

The agents did not differ significantly in efficacy for most infections; although, ampicillin-sulbactam was bacteriologically superior to ticarcillin-clavulanate in the treatment of intraabdominal infections (p=0.0011). Costs of ampicillin-sulbactam, particularly the 1.5-g dose, were lower than those of ticarcillin-clavulanate for skin and soft tissue (p<0.001), intraabdominal (p=0.005), and respiratory tract (p<0.001) infections.

CONCLUSION

Ampicillin-sulbactam provides effective coverage for patients with the above infections and is as effective as the broader-spectrum agent.

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.