Single-dose oral ciprofloxacin plus parenteral metronidazole for perioperative antibiotic prophylaxis in colorectal surgery

The Role of Oral Antibiotic Preparation in Elective Colorectal Surgery: A Meta-analysis

OBJECTIVES

To compare the impact of the use of oral antibiotics (OAB) with or without mechanical bowel preparation (MBP) on outcome in elective colorectal surgery.

SUMMARY BACKGROUND DATA

Meta-analyses have demonstrated that MBP does not impact upon postoperative morbidity or mortality, and as such it should not be prescribed routinely. However, recent evidence from large retrospective cohort and database studies has suggested that there may be a role for combined OAB and MBP, or OAB alone in the prevention of surgical site infection (SSI).

METHODS

A meta-analysis of randomized controlled trials and cohort studies including adult patients undergoing elective colorectal surgery, receiving OAB with or without MBP was performed. The outcome measures examined were SSI, anastomotic leak, 30-day mortality, overall morbidity, development of ileus, reoperation and Clostridium difficile infection.

RESULTS

A total of 40 studies with 69,517 patients (28 randomized controlled trials, n = 6437 and 12 cohort studies, n = 63,080) were included. The combination of MBP+OAB versus MBP alone was associated with a significant reduction in SSI [risk ratio (RR) 0.51, 95% confidence interval (CI) 0.46-0.56, P < 0.00001, I = 13%], anastomotic leak (RR 0.62, 95% CI 0.55-0.70, P < 0.00001, I = 0%), 30-day mortality (RR 0.58, 95% CI 0.44-0.76, P < 0.0001, I = 0%), overall morbidity (RR 0.67, 95% CI 0.63-0.71, P < 0.00001, I = 0%), and development of ileus (RR 0.72, 95% CI 0.52-0.98, P = 0.04, I = 36%), with no difference in Clostridium difficile infection rates. When a combination of MBP+OAB was compared with OAB alone, no significant difference was seen in SSI or anastomotic leak rates, but there was a significant reduction in 30-day mortality, and incidence of postoperative ileus with the combination. There is minimal literature available on the comparison between combined MBP+OAB versus no preparation, OAB alone versus no preparation, and OAB versus MBP.

CONCLUSIONS

Current evidence suggests a potentially significant role for OAB preparation, either in combination with MBP or alone, in the prevention of postoperative complications in elective colorectal surgery. Further high-quality evidence is required to differentiate between the benefits of combined MBP+OAB or OAB alone.

The role of oral antibiotics prophylaxis in prevention of surgical site infection in colorectal surgery

BACKGROUND

Surgical site infection (SSI) continues to be a challenge in colorectal surgery. Over the years, various modalities have been used in an attempt to reduce SSI risk in elective colorectal surgery, which include mechanical bowel preparation before surgery, oral antibiotics and intravenous antibiotic prophylaxis at induction of surgery. Even though IV antibiotics have become standard practice, there has been a debate on the exact role of oral antibiotics.

AIM

The primary aim was to identify the role of oral antibiotics in reduction of SSI in elective colorectal surgery. The secondary aim was to explore any potential benefit in the use of mechanical bowel preparation (MBP) in relation to SSI in elective colorectal surgery.

METHODS

Medline, Embase and the Cochrane Library were searched. Any randomised controlled trials (RCTs) or cohort studies after 1980, which investigated the effectiveness of oral antibiotic prophylaxis and/or MBP in preventing SSIs in elective colorectal surgery were included.

RESULTS

Twenty-three RCTs and eight cohorts were included. The results indicate a statistically significant advantage in preventing SSIs with the combined usage of oral and systemic antibiotic prophylaxis. Furthermore, our analysis of the cohort studies shows no benefits in the use of MBP in prevention of SSIs.

CONCLUSIONS

The addition of oral antibiotics to systemic antibiotics could potentially reduce the risk of SSIs in elective colorectal surgery. Additionally, MBP does not seem to provide a clear benefit with regard to SSI prevention.

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.

Septic complications of elective laparoscopic colorectal resection

BACKGROUND

We set out to determine the rate and pattern of septic complications of the surgical wound, abdominal cavity, and urinary and respiratory tracts following laparoscopic colorectal resection.

METHODS

A longitudinal database of 500 consecutive cases of colorectal resections was reviewed.

RESULTS

The total wound infection rate was 7.2% (36/500) and included infections of the abdominal wall wounds (32/500, 6.4%) and the perineal wounds (4/50, 8%). The anastomotic leak rate in 418 patients who underwent resection with primary anastomosis was 3.3% (14/418). Intraabdominal abscesses were diagnosed in 1% (5/500) of patients. Urinary tract infections were rare (3/500, 0.6%), as was postoperative pneumonia (6/500, 1%).

CONCLUSIONS

This study confirms the low rate of postoperative pneumonia observed with all other minimally invasive procedures. Intraabdominal abscesses, urinary tract infections, and postoperative pneumonia occur considerably less frequently than in reported historical controls for open surgery. The rates of abdominal wound infection and anastomotic leak in laparoscopic colorectal resection appear to be equivalent to traditional surgery, whereas the rate of perineal wound sepsis is lower. Comparative studies are needed to determine the differential costs of the septic episodes associated with the two approaches.

Management of prosthesis infections in urologic surgery

Prosthetic devices are a cornerstone of urologic surgical care. The most disastrous complication of these surgical procedures is infection. The prevention, identification, and management of infections are critical to maintaining functional urologic prosthetic devices. Although the incidence is low, rapid identification of infections once they occur and proper management with antibiotics, surgical intervention, irrigation, and salvage procedures can maintain the function of urologic prosthetic devices despite clinical infection.

Metronidazole. A therapeutic review and update

The nitroimidazole antibiotic metronidazole has a limited spectrum of activity that encompasses various protozoans and most Gram-negative and Gram-positive anaerobic bacteria. Metronidazole has activity against protozoans like Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis, for which the drug was first approved as an effective treatment. Anaerobic bacteria which are typically sensitive are primarily Gram-negative anaerobes belonging to the Bacteroides and Fusobacterium spp. Gram-positive anaerobes such as peptostreptococci and Clostridia spp. are likely to test sensitive to metronidazole, but resistant isolates are probably encountered with greater frequency than with the Gram-negative anaerobes. Gardnerella vaginalis is a pleomorphic Gram-variable bacterial bacillus that is also susceptible to metronidazole. Helicobacter pylori has been strongly associated with gastritis and duodenal ulcers. Classic regimens for eradicating this pathogen have included metronidazole, usually with acid suppression medication plus bismuth and amoxicillin. The activity of metronidazole against anaerobic bowel flora has been used for prophylaxis and treatment of patients with Crohn's disease who might develop an infectious complication. Treatment of Clostridium difficile-induced pseudomembraneous colitis has usually been with oral metronidazole or vancomycin, but the lower cost and similar efficacy of metronidazole, coupled with the increased concern about imprudent use of vancomycin leading to increased resistance in enterococci, have made metronidazole the preferred agent here. Metronidazole has played an important role in anaerobic-related infections. Advantages to using metronidazole are the percentage of sensitive Gram-negative anaerobes, its availability as oral and intravenous dosage forms, its rapid bacterial killing, its good tissue penetration, its considerably lower chance of inducing C. difficile colitis, and expense. Metronidazole has notable effectiveness in treating anaerobic brain abscesses. Metronidazole is a cost-effective agent due to its low acquisition cost, its pharmacokinetics and pharmacodynamics, an acceptable adverse effect profile, and its undiminished antimicrobial activity. While its role as part of a therapeutic regimen for treating mixed aerobic/anaerobic infections has been reduced by newer, more expensive combination therapies, these new combinations have not been shown to have any therapeutic advantage over metronidazole. Although the use of metronidazole on a global scale has been curtailed by newer agents for various infections, metronidazole still has a role for these and other therapeutic uses. Many clinicians still consider metronidazole to be the 'gold standard' antibiotic against which all other antibiotics with anaerobic activity should be compared.