Parenteral and oral antibiotics in elective colon and rectal surgery. A prospective, randomized trial

Preoperative combined mechanical and oral antibiotic bowel preparation for preventing complications in elective colorectal surgery

BACKGROUND

The success of elective colorectal surgery is mainly influenced by the surgical procedure and postoperative complications. The most serious complications include anastomotic leakages and surgical site infections (SSI)s, which can lead to prolonged recovery with impaired long-term health.  Compared with other abdominal procedures, colorectal resections have an increased risk of adverse events due to the physiological bacterial colonisation of the large bowel. Preoperative bowel preparation is used to remove faeces from the bowel lumen and reduce bacterial colonisation. This bowel preparation can be performed mechanically and/or with oral antibiotics. While mechanical bowel preparation alone is not beneficial, the benefits and harms of combined mechanical and oral antibiotic bowel preparation is still unclear.

OBJECTIVES

To assess the evidence for the use of combined mechanical and oral antibiotic bowel preparation for preventing complications in elective colorectal surgery.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and trial registries on 15 December 2021. In addition, we searched reference lists and contacted colorectal surgery organisations.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adult participants undergoing elective colorectal surgery comparing combined mechanical and oral antibiotic bowel preparation (MBP+oAB) with either MBP alone, oAB alone, or no bowel preparation (nBP). We excluded studies in which no perioperative intravenous antibiotic prophylaxis was given.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. Pooled results were reported as mean difference (MD) or risk ratio (RR) and 95 % confidence intervals (CIs) using the Mantel-Haenszel method. The certainty of the evidence was assessed with GRADE.

MAIN RESULTS

We included 21 RCTs analysing 5264 participants who underwent elective colorectal surgery. None of the included studies had a high risk of bias, but two-thirds of the included studies raised some concerns. This was mainly due to the lack of a predefined analysis plan or missing information about the randomisation process. Most included studies investigated both colon and rectal resections due to malignant and benign surgical indications. For MBP as well as oAB, the included studies used different regimens in terms of agent(s), dosage and timing.  Data for all predefined outcomes could be extracted from the included studies. However, only four studies reported on side effects of bowel preparation, and none recorded the occurrence of adverse effects such as dehydration, electrolyte imbalances or the need to discontinue the intervention due to side effects. Seventeen trials compared MBP+oAB with sole MBP. The incidence of SSI could be reduced through MBP+oAB by 44% (RR 0.56, 95% CI 0.42 to 0.74; 3917 participants from 16 studies; moderate-certainty evidence) and the risk of anastomotic leakage could be reduced by 40% (RR 0.60, 95% CI 0.36 to 0.99; 2356 participants from 10 studies; moderate-certainty evidence). No difference between the two comparison groups was found with regard to mortality (RR 0.87, 95% CI 0.27 to 2.82; 639 participants from 3 studies; moderate-certainty evidence), the incidence of postoperative ileus (RR 0.89, 95% CI 0.59 to 1.32; 2013 participants from 6 studies, low-certainty of evidence) and length of hospital stay (MD -0.19, 95% CI -1.81 to 1.44; 621 participants from 3 studies; moderate-certainty evidence). Three trials compared MBP+oAB with sole oAB. No difference was demonstrated between the two treatment alternatives in terms of SSI (RR 0.87, 95% CI 0.34 to 2.21; 960 participants from 3 studies; very low-certainty evidence), anastomotic leakage (RR 0.84, 95% CI 0.21 to 3.45; 960 participants from 3 studies; low-certainty evidence), mortality (RR 1.02, 95% CI 0.30 to 3.50; 709 participants from 2 studies; low-certainty evidence), incidence of postoperative ileus (RR 1.25, 95% CI 0.68 to 2.33; 709 participants from 2 studies; low-certainty evidence) or length of hospital stay (MD 0.1 respectively 0.2, 95% CI -0.68 to 1.08; data from 2 studies; moderate-certainty evidence). One trial (396 participants) compared MBP+oAB versus nBP. The evidence is uncertain about the effect of MBP+oAB on the incidence of SSI as well as mortality (RR 0.63, 95% CI 0.33 to 1.23 respectively RR 0.20, 95% CI 0.01 to 4.22; low-certainty evidence), while no effect on the risk of anastomotic leakages (RR 0.89, 95% CI 0.33 to 2.42; low-certainty evidence), the incidence of postoperative ileus (RR 1.18, 95% CI 0.77 to 1.81; low-certainty evidence) or the length of hospital stay (MD 0.1, 95% CI -0.8 to 1; low-certainty evidence) could be demonstrated.

AUTHORS' CONCLUSIONS

Based on moderate-certainty evidence, our results suggest that MBP+oAB is probably more effective than MBP alone in preventing postoperative complications. In particular, with respect to our primary outcomes, SSI and anastomotic leakage, a lower incidence was demonstrated using MBP+oAB. Whether oAB alone is actually equivalent to MBP+oAB, or leads to a reduction or increase in the risk of postoperative complications, cannot be clarified in light of the low- to very low-certainty evidence. Similarly, it remains unclear whether omitting preoperative bowel preparation leads to an increase in the risk of postoperative complications due to limited evidence. Additional RCTs, particularly on the comparisons of MBP+oAB versus oAB alone or nBP, are needed to assess the impact of oAB alone or nBP compared with MBP+oAB on postoperative complications and to improve confidence in the estimated effect. In addition, RCTs focusing on subgroups (e.g. in relation to type and location of colon resections) or reporting side effects of the intervention are needed to determine the most effective approach of preoperative bowel preparation.

Bundles reduce anastomosis leak in patients undergoing elective colorectal surgery. A propensity score-matched study

Background

anastomosis leak still being a handicap in colorectal surgery. Bowel mechanical preparation and oral antibiotics are not a practice recommended in many clinical practice guides. The aim is to analyse the decrease in frequency and severity of postoperative complications, mainly related to anastomotic leak, after the establishment of a bundle.

Methods

Single-center, before-after study. A bundle was implemented to reduce anastomotic leaks and their consequences. The Bundle group were matched to Pre-bundle group by propensity score matching. Mechanical bowel preparation, oral and intravenous antibiotics, inflammatory markers measure and early diagnosis algorithm were included at the bundle.

Results

The bundle group shown fewer complications, especially in Clavien Dindós Grade IV complications (2.3% vs. 6.2% p < 0.01), as well as a lower rate of anastomotic leakage (15.5% vs. 2.2% p < 0.01). A significant decrease in reinterventions, less intensive unit care admissions, a shorter hospital stay and fewer readmissions were also observed. In multivariate analysis, the application of a bundle was an anastomotic leakage protective factor (OR 0.121, p > 0.05).

Conclusions

The implementation of our bundle in colorectal surgery which include oral antibiotics, mechanical bowel preparation and inflammatory markers, significantly reduces morbidity adjusted to severity of complications, the anastomotic leakage rate, hospital stay and readmissions.

Register study

The study has been registered at clinicaltrials.gov Code: nct04632446.

Risk adjustment performance between NNIS index and NHSN model for postoperative colorectal surgical site infection: A retrospective cohort study

Background

Risk stratifications to predict development of surgical site infections (SSI) are crucial methods before surgery. Hence, we aimed to compare the performance of risk adjustment between the former NNIS risk index and the new NHSN procedure-specific risk model for postoperative colorectal SSI.

Materials and methods

A retrospective cohort study was conducted. Data of post-colorectal SSI, indicating the use of the NNIS risk index for SSI adjustment, were retrieved from the medical records. Data were taken from patients who underwent colorectal surgery procedures between January 2005 and December 2016. Additional information regarding emergency colorectal surgery was retrieved to fulfill the requirements for calculation of the risks for SSI; via the new model. The predictive performance between the two models was compared using the means of the area under the receiver operating characteristic curve.

Results

In total 1989 patients were included. Fifteen patients were excluded; thus, the remaining number of procedures was 1974. Surgical site infections occurred in 85 (4.3%) procedures. In colectomy surgery, the means of area under the curve (AUC) yielded 0.6196 and 0.5976 for the NNIS risk index model and the new NHSN risk model, respectively; differences in the AUC were not statistically significant (p = 0.39). In rectal surgery, the means of the AUC yielded 0.516 and 0.49 for the NNIS risk index model and the new NHSN procedure-specific risk model, respectively; differences in the AUC were not statistically significant (p = 0.56).

Conclusion

The new NHSN procedure-specific risk model was not superior to the former NNIS risk index.

•

The NHSN risk model was not superior to the NNIS risk index.

•

The recommendation is for the application of the NNIS risk index be applied.

•

This is the first reporting on the novel performance of CDC risk adjustment for colorectal SSI.

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This paper builds upon concerns for infectious, nosocomial surveillances; especially for low resources countries.

Strategies for Antibiotic Administration for Bowel Preparation Among Patients Undergoing Elective Colorectal Surgery: A Network Meta-analysis

Importance

There are discrepancies in guidelines on preparation for colorectal surgery. While intravenous (IV) antibiotics are usually administered, the use of mechanical bowel preparation (MBP), enemas, and/or oral antibiotics (OA) is controversial.

Objective

To summarize all data from randomized clinical trials (RCTs) that met selection criteria using network meta-analysis (NMA) to determine the ranking of different bowel preparation treatment strategies for their associations with postoperative outcomes.

Data Sources

Data sources included MEDLINE, Embase, Cochrane, and Scopus databases with no language constraints, including abstracts and articles published prior to 2021.

Study Selection

Randomized studies of adults undergoing elective colorectal surgery with appropriate aerobic and anaerobic antibiotic cover that reported on incisional surgical site infection (SSI) or anastomotic leak were selected for inclusion in the analysis. These were selected by multiple reviewers and adjudicated by a separate lead investigator. A total of 167 of 6833 screened studies met initial selection criteria.

Data Extraction and Synthesis

NMA was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Data were extracted by multiple independent observers and pooled in a random-effects model.

Main Outcomes and Measures

Primary outcomes were incisional SSI and anastomotic leak. Secondary outcomes included other infections, mortality, ileus, and adverse effects of preparation.

Results

A total of 35 RCTs that included 8377 patients were identified. Treatments compared IV antibiotics (2762 patients [33%]), IV antibiotics with enema (222 patients [3%]), IV antibiotics with OA with or without enema (628 patients [7%]), MBP with IV antibiotics (2712 patients [32%]), MBP with IV antibiotics with OA (with good IV antibiotic cover in 925 patients [11%] and with good overall antibiotic cover in 375 patients [4%]), MBP with OA (267 patients [3%]), and OA (486 patients [6%]). The likelihood of incisional SSI was significantly lower for those receiving IV antibiotics with OA with or without enema (rank 1) and MBP with adequate IV antibiotics with OA (rank 2) compared with all other treatment options. The addition of OA to IV antibiotics, both with and without MBP, was associated with a reduction in incisional SSI by greater than 50%. There were minimal differences between treatments in anastomotic leak and in any of the secondary outcomes.

Conclusions and Relevance

This NMA demonstrated that the addition of OA to IV antibiotics were associated with a reduction in incisional SSI by greater than 50%. The results support the addition of OA to IV antibiotics to reduce incisional SSI among patients undergoing elective colorectal surgery.

Impact of oral antibiotic prophylaxis on surgical site infection after rectal surgery: results of randomized trial

AIM

To evaluate the impact of oral antibiotic prophylaxis on surgical site infection (SSI) rate after rectal surgery.

METHODS

It was a single-center 1:1 randomized controlled open parallel trial (registration number NCT03436719). The patients undergoing rectal resection for benign and malignant tumors were assigned randomly to two groups: the oral plus intravenous (IV) antibiotic prophylaxis (AP) and the IV antibiotic prophylaxis only. The primary endpoint was the overall rate of SSI.

RESULTS

Between November 2017 and December 2018, 116 (male-55, the mean age-64 years) patients were enrolled into the trial. Of them, 57 had oral erythromycin 500 mg + metronidazole 500 mg a day before surgery and 1,000 mg of cephalosporin IV 30-90 min before operation. In the other group, 59 patients had the same IV antibiotics only. The incidence of SSIs was 22% (13/59) and 3.5% (2/57) correspondingly (р = 0.002). The statistically significant difference was detected for superficial SSI 0 (0%) vs. 5 (8.5%) (p = 0.03) and organ/space SSI 2 (3.5%) vs. 9 (15.3%) (p = 0.03), respectively. A multivariate analysis of risk factors of SSI identified two independent ones: bacterial contamination of the pelvic cavity ≥ 10⁵ CFU at the end of surgery OR 17.9, 95% CI 2.1-150.0 (p = 0.008) and oral antimicrobial prophylaxis OR 0.2, 95% CI 0.03-0.8 (p = 0.02).

CONCLUSION

Oral-parenteral AP significantly reduced the risk of SSI following elective rectal surgery. Bacterial contamination of the pelvic cavity ≥ 10⁵ CFU at the end of surgery and oral antimicrobial prophylaxis were independent risk factors of SSI.

Is the efficacy of antibiotic prophylaxis for surgical procedures decreasing? Systematic review and meta-analysis of randomized control trials

OBJECTIVE

Rising antibiotic resistance could reduce the effectiveness of antibiotics in preventing postoperative infections. We investigated trends in the efficacy of antibiotic prophylaxis regimens for 3 commonly performed surgical procedures-appendectomy, cesarean section, and colorectal surgery-and 1 invasive diagnostic procedure, transrectal prostate biopsy (TRPB).

DESIGN

Systematic review and meta-analysis.

METHODS

We searched PubMed and Cochrane databases (through October 31, 2017) for randomized control trials (RCTs) that measured the efficacy of antibiotic prophylaxis for 4 index procedures in preventing postoperative infections (surgical site infections [SSIs] following the 3 surgical procedures and a combination of urinary tract infections [UTIs] and sepsis following TRPB).

RESULTS

Of 399 RCTs, 74 studies (9 appendectomy, 11 cesarean section, 39 colorectal surgery, and 15 TRPB) were included. Multilevel logistic regression models with random intercepts for each study showed no statistically significant increase in SSIs over time for appendectomy (adjusted odds ratio [aOR] per year, 1.03; 95% confidence interval [CI], 0.92-1.16; P=.57), cesarean section (aOR per year, 1.01; 95% CI, 0.96-1.05; P=.80), and TRPB (aOR per year, 0.95; 95% CI, 0.77-1.18; P=.67). However, there was a significant increase in SSIs proportion following colorectal surgery (aOR per year, 1.049; 95% CI, 1.03-1.07; P&lt;.001).

CONCLUSION

The efficacy of antibiotic prophylaxis agents in preventing SSIs following colorectal surgery has declined. Small number of RCTs and low infections rates limited our ability to assess true effect for simple appendectomy, cesarean section, or TRPB.

ORAL ANTIBIOTIC PROPHYLAXIS IN COLORECTAL SURGERY (systematic review and network meta-analysis)

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The efficacy of active drainage for preventing postoperative organ/space surgical site infections in patients with Crohn's disease

PURPOSE

Patients with Crohn's disease (CD) show a higher incidence of surgical site infections (SSIs) after bowel resection in comparison to other patient populations because CD patients commonly suffer from anemia, malnutrition, and immunosuppression. In comparison to conventional passive drainage, active drainage using a closed-suction drain reportedly reduces postoperative wound-related complications in several diseases. In the present study, we aimed to investigate the incidence of SSI and to identify the risk factors for SSI in patients with CD.

METHODS

We retrospectively analyzed the patient characteristics and perioperative data of 106 CD patients who underwent bowel resection at our institution between January 2000 and June 2016. We statistically analyzed the incidence of different types of SSI (overall, incisional, and organ/space) in relation to patient-related and surgery-related risk factors.

RESULTS

Overall postoperative SSIs were diagnosed in 19 patients (17.9%), including incisional SSI (n = 16; 15.1%), organ/space SSI (n = 7; 6.6%), and both (n = 4; 3.8%). A long operative time (p = 0.036) and colonic involvement (p = 0.011) were significantly associated with the overall risk of developing an SSI. Active drainage significantly reduced the incidence of organ/space SSI (p = 0.037).

CONCLUSION

Intraabdominal active drainage was more useful than passive drainage for preventing organ/space SSI development.

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 Bowel Preparation for Elective Colon Surgery

BACKGROUND

Mechanical bowel preparation continues to be a controversial subject for the pre-operative management of patients undergoing elective colon resection.

METHODS

The English literature on bowel preparation was searched to identify pertinent publications.

RESULTS

The published literature over the past 80 y confirms that mechanical bowel preparation alone does not reduce surgical site infections. However, the use of appropriate oral antibiotics following mechanical bowel preparation with pre-operative systemic antibiotics reduces rates of surgical site infections and anastomotic leaks when compared with systemic antibiotics alone.

CONCLUSIONS

Mechanical bowel preparation with pre-operative oral antibiotics and pre-operative systemic antibiotics are the standard of care for elective colon surgery. Refinement in methods of bowel preparation needs additional clinical investigations to further enhance outcomes.

Risk factors for surgical site infection following colorectal resection: a multi-institutional study

INTRODUCTION

Surgical site infection (SSI) is an infection occurring in an incisional wound within 30 days of surgery and significantly affects patients undergoing colorectal surgery. This study examined a multi-institutional dataset to determine risk factors for SSI following colorectal resection.

METHODS

Data on 386 patients who underwent colorectal resection in three institutions were accrued. Patients were identified using a prospective SSI database and hospital records. Data are presented as median (interquartile range), and logistic regression analysis was used to identify risk factors.

RESULTS

Patients (21.5%) developed a postoperative SSI. The median time to the development of SSI was 7 days (5-10). Of all infections, 67.5% were superficial, 22.9% were deep and 9.6% were organ space. In univariate analysis, an ASA grade of II (RR 0.6, CI 0.3-0.9, P = 0.019), having an elective procedure (RR 0.4, CI 0.2-0.6, P < 0.001), using a laparoscopic approach (RR 0.5, CI 0.3-0.9, P = 0.019), having a daytime procedure (RR 0.3, CI 0.1-0.7, P = 0.006) and having a clean/contaminated wound (RR 0.4, CI 0.2-0.7, P = 0.001) were associated with reduced risk of SSI. In multivariate analysis, an ASA grade of IV (RR 3.9, CI 1.1-13.7, P = 0.034), a procedure duration over 3 h (RR 4.3, CI 2.3-8.2, P < 0.001) and undergoing a panproctocolectomy (RR 6.5, CI 1.0-40.9, P = 0.044) were independent risk factors for SSI. Those who developed an SSI had a longer duration of inpatient stay (22 days [16-31] vs 15 days [10-26], P < 0.001).

CONCLUSIONS

Patients who develop an SSI have a longer duration of inpatient stay. Independent risk factors for SSI following colorectal resection include being ASA grade IV, having a procedure duration over 3 h, and undergoing a panproctocolectomy.

Novel Method of Surgical Incision Management in Patients Undergoing Colorectal Surgery

We previously demonstrated that subcutaneous drain is effective for preventing incisional surgical site infection (SSI) in patients with thick subcutaneous fat in colorectal surgery. We have recently attempted a novel closure technique in colorectal surgery for the prevention of incisional SSI. In the current study, we described this novel method for prevention of incisional SSI and share our assessment of efficiency of this incision management in patients undergoing colorectal surgery. The procedure “wound dressing with temporary negative pressure” using Opsite Post-Op Visible and an Atom Multipurpose Tube, is a simple and easy method. Immediately after incisions were closed, Opsite Post-Op Visible dressing was applied over the incision site with an Atom Multipurpose catheter, and negative pressure was applied through the catheter. We analyzed the cases of 203 patients who underwent colorectal resection. In 60 cases, we performed this negative pressure system for prevention of SSI. We reviewed the clinical features of these cases treated by this novel method and found that the incisional SSI rate in patients who underwent colorectal resection was significantly reduced following the use of the new method. There were no complications in any of the cases due to DNP. This dressing with negative pressure (DNP) may lead to wound drainage and a reduction of dead space in a subcutaneous wound area. These findings indicate that the use of DNP is safe, easy, and effective for preventing incisional SSI in patients undergoing colorectal surgery.

Combined preoperative mechanical bowel preparation with oral antibiotics significantly reduces surgical site infection, anastomotic leak, and ileus after colorectal surgery

OBJECTIVES

To clarify whether bowel preparation use or its individual components [mechanical bowel preparation (MBP)/oral antibiotics] impact specific outcomes after colorectal surgery.

METHODS

National Surgical Quality Improvement Program-targeted colectomy data initiated in 2012 capture information on the use/type of bowel preparation and colorectal-specific complications. For patients undergoing elective colorectal resection, the impact of preoperative MBP and antibiotics (MBP+/ABX+), MBP alone (MBP+/ABX-), and no bowel preparation (no-prep) on outcomes, particularly anastomotic leak, surgical site infection (SSI), and ileus, were evaluated using unadjusted/adjusted logistic regression analysis.

RESULTS

Of 8442 patients, 2296 (27.2%) had no-prep, 3822 (45.3%) MBP+/ABX-, and 2324 (27.5%) MBP+/ABX+. Baseline characteristics were similar; however, there were marginally more patients with prior sepsis, ascites, steroid use, bleeding disorders, and disseminated cancer in no-prep. MBP with or without antibiotics was associated with reduced ileus [MBP+/ABX+: odds ratio (OR) = 0.57, 95% confidence interval (CI): 0.48-0.68; MBP+/ABX-: OR = 0.78, 95% CI: 0.68-0.91] and SSI [MBP+/ABX+: OR = 0.39, 95% CI: 0.32-0.48; MBP+/ABX-: OR = 0.80, 95% CI: 0.69-0.93] versus no-prep. MBP+/ABX+ was also associated with lower anastomotic leak rate than no-prep [OR = 0.45 (95% CI: 0.32-0.64)]. On multivariable analysis, MBP with antibiotics, but not without, was independently associated with reduced anastomotic leak (OR = 0.57, 95% CI: 0.35-0.94), SSI (OR = 0.40, 95% CI: 0.31-0.53), and postoperative ileus (OR = 0.71, 95% CI: 0.56-0.90).

CONCLUSIONS

These data clarify the near 50-year debate whether bowel preparation improves outcomes after colorectal resection. MBP with oral antibiotics reduces by nearly half, SSI, anastomotic leak, and ileus, the most common and troublesome complications after 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.

The prevention of surgical site infection in elective colon surgery

Infections at the surgical site continue to occur in as many as 20% of elective colon resection cases. Methods to reduce these infections are inconsistently applied. Surgical site infection (SSI) is the result of multiple interactive variables including the inoculum of bacteria that contaminate the site, the virulence of the contaminating microbes, and the local environment at the surgical site. These variables that promote infection are potentially offset by the effectiveness of the host defense. Reduction in the inoculum of bacteria is achieved by appropriate surgical site preparation, systemic preventive antibiotics, and use of mechanical bowel preparation in conjunction with the oral antibiotic bowel preparation. Intraoperative reduction of hematoma, necrotic tissue, foreign bodies, and tissue dead space will reduce infections. Enhancement of the host may be achieved by perioperative supplemental oxygenation, maintenance of normothermia, and glycemic control. These methods require additional research to identify optimum application. Uniform application of currently understood methods and continued research into new methods to reduce microbial contamination and enhancement of host responsiveness can lead to better outcomes.

Bowel Preparation before Elective Surgery

Mechanical bowel preps were initially thought to decrease the bacterial load of the colon and therefore decrease infection. Traditional bowel preps include osmotic, laxative, and combination regimen. Data demonstrate that mechanical bowel preps are generally equivalent; however, the addition of oral antibiotics may further reduce the risk of infection. Recent data suggest that mechanical bowel preparations may not be necessary, and that dietary restrictions before surgery may also be obsolete. In this review, the authors address the types of mechanical bowel preparations (MBPs), differences in outcomes between MBPs, the role of oral antibiosis and enemas, the benefits of no MBP, and dietary preparations for elective colon and rectal surgery.

Triclosan-coated sutures reduce the incidence of wound infections and the costs after colorectal surgery: a randomized controlled trial

BACKGROUND

In colorectal surgeries, surgical site infections (SSIs) frequently cause morbidity; an incidence of up to 20% has been shown in previous studies. Recently, to prevent microbial colonization of suture material in operative wounds, triclosan-coated polyglactin suture materials with antimicrobial activity have been developed; however, their significance in colorectal surgery remains unclear. This randomized controlled trial was conducted to assess the value of triclosan-coated polyglactin sutures in colorectal surgery.

METHODS

A total of 410 consecutive patients who had undergone elective colorectal operations were enrolled in this trial. Of those patients, the 206 in the study group underwent wound closure with triclosan-coated polyglactin 910 antimicrobial sutures, and the 204 patients in the control group received conventional wound closures with polyglactin 910 sutures.

RESULTS

The study group and the control group were comparable regarding risk factors for SSIs. The incidence of wound infection in the study group was 9 of 206 patients (4.3%), and that in the control group was 19 of 204 patients (9.3%). The difference is statistically significant in the 2 groups (P = .047). The median additional cost of wound infection management was $2,310. The actual entire additional cost, therefore, of 9 patients in the study group was $18,370, and that of 19 patients in the control group was $60,814.

CONCLUSION

Triclosan-coated sutures can reduce the incidence of wound infections and the costs in colorectal surgery.

Effects of subcutaneous drain for the prevention of incisional SSI in high-risk patients undergoing colorectal surgery

INTRODUCTION

We have previously demonstrated that the risk of incisional surgical site infection (SSI) increases with obesity and that the most useful predictor of incisional SSI is the thickness of subcutaneous fat. Based on this finding, we have recently attempted a closure technique in surgery for the obese in which a subcutaneous drain is inserted for the prevention of incisional SSI. The aim of this study was to assess the utility of a subcutaneous drain for preventing incisional SSI in patients undergoing colorectal surgery who are at high risk for incisional SSI.

MATERIALS AND METHODS

Seventy-nine patients who underwent colorectal resection with high risk for incisional SSI, including patients with obesity (thick subcutaneous fat tissue, >20 mm) and those undergoing emergency operations, were enrolled in this study. The clinical features of these cases with or without a subcutaneous drain were reviewed, and statistical analysis was performed.

RESULTS

In these high-risk cases, the overall incidence of incisional SSI was 27.8%. The incidences of incisional SSI in these cases with or without a subcutaneous drain were 14.3% and 38.6%, respectively. Our results suggest that subcutaneous drains are effective for preventing incisional SSI in patients with thick subcutaneous fat in colorectal surgery.

CONCLUSION

Therefore, incisional SSI surveillance for obese patients should be performed separately, which should lead to a further reduction in incisional SSIs.

Differing risk factors for incisional and organ/space surgical site infections following abdominal colorectal surgery

OBJECTIVE

Surgical site infections are a major source of morbidity after colorectal surgery. The aim of this study was to explore differences between incisional and organ/space surgical site infection types by evaluating risk factors, National Nosocomial Risk Index Scores, and clinical outcomes.

DESIGN

A random sample of adults undergoing abdominal colorectal surgery between June 2001 and July 2008 was extracted from a colorectal surgery practice database. Patient factors, comorbidities, intraoperative factors, postoperative factors, and infection were collected; risk score (from -1 to 3 points) was calculated. Variables associated with surgical site infection by univariate analysis were incorporated in a multivariable model to identify risk factors by infection type. Infection risk by risk score was evaluated by logistic regression. Length of stay, readmission, and mortality were examined by infection type.

RESULTS

Six hundred fifty subjects were identified: 312 were male, age was 59.8 (SD 17.8) years. Common preoperative diagnoses included colorectal cancer (36.9%) and inflammatory bowel disease (21.7%). Forty-five cases were emergencies, and 171 included rectal resections. Eighty-two patients developed incisional and 64 developed organ/space surgical site infections. Body mass index was associated with incisional infection (OR 1.05, 95% CI 1.00-1.09), whereas previous radiation (OR 4.49, 95% CI 1.53-13.18), postoperative hyperglycemia (OR 2.99, 95% CI 1.41-6.34), preoperative [albumin] (OR 0.52, 95% CI 0.36-0.76), and case length (OR 1.26, 95% CI 1.08-1.47) were associated with organ/space infection. A risk score of 2 and above, compared with a score of <2, predicted organ/space (OR 5.92, 95% CI 3.16-11.09) but not incisional infection (OR 0.95, 95% CI 0.41-2.16). Organ/space infections were associated with longer length of stay (P = .006) and higher readmission rates (P < .001) than incisional infections.

CONCLUSIONS

Risk factors for surgical site infections differ by type of infection. Clinical outcomes and value of the risk index score are different by infection type. It may be prudent to consider incisional and organ/space surgical site infections as different entities for patients undergoing colorectal surgery.

Right colon, left colon, and rectal surgeries are not similar for surgical site infection development. Analysis of 277 elective and urgent colorectal resections

PURPOSE

Surgical site infections (SSIs) are the most common infections in colorectal surgery. Although some studies suggest that rectal surgery differs from colon surgery for SSI incidence and risk factors, the National Nosocomial Infection Surveillance system categorizes all colorectal surgeries into only one group. The aim of this study was to determine incidence, characteristics, and risk factors of SSIs according to the subclassification of colorectal surgery into right colon surgery (RCS), left colon surgery (LCS), and rectum surgery (RS).

METHODS

From November 2005 to July 2009, all patients requiring colorectal resectioning were enrolled into our program. The outcome of interest was an SSI diagnosis. Univariate and multivariate analyses were performed to determine SSI predictors in each group.

RESULTS

Two hundred seventy-seven consecutive colorectal resections were analyzed. SSI rates were 8% in RCS, 18.4% in LCS, and 17.6% in RS. LCS and RS showed significantly higher SSI incidences (p = 0.022) and greater rates of organ/space infections compared to RCS (p = 0.029). Predictors of SSI were steroid use among RCS, age greater than 70 years, multiple comorbidities, steroid use, non-neoplastic colonic disease, urgent operation, ostomy creation, postoperative intensive care among LCS, preoperative chemoradiation, heart disease, and prolonged operation among RS patients. On multivariate analysis, the coupled LCS and RS groups showed an increased risk for SSI compared to RCS (OR, 2.57).

CONCLUSIONS

SSI incidences, characteristics, and risk factors seem to be different among RCS, LCS, and RS. A tailored SSI surveillance program should be applied for each of the three groups, leading to a more competent SSI recognition and reduction of SSI incidence and related costs.

A statewide assessment of surgical site infection following colectomy: the role of oral antibiotics

OBJECTIVE

To determine the utility of adding oral nonabsorbable antibiotics to the bowel prep prior to elective colon surgery.

SUMMARY BACKGROUND DATA

Bowel preparation prior to colectomy remains controversial. We hypothesized that mechanical bowel preparation with oral antibiotics (compared with without) was associated with lower rates of surgical site infection (SSI).

METHODS

Twenty-four Michigan hospitals participated in the Michigan Surgical Quality Collaborative-Colectomy Best Practices Project. Standard perioperative data, bowel preparation process measures, and Clostridium difficile colitis outcomes were prospectively collected. Among patients receiving mechanical bowel preparation, a logistic regression model generated a propensity score that allowed us to match cases differing only in whether or not they had received oral antibiotics.

RESULTS

Overall, 2011 elective colectomies were performed over 16 months. Mechanical bowel prep without oral antibiotics was administered to 49.6% of patients, whereas 36.4% received a mechanical prep and oral antibiotics. Propensity analysis created 370 paired cases (differing only in receiving oral antibiotics). Patients receiving oral antibiotics were less likely to have any SSI (4.5% vs. 11.8%, P = 0.0001), to have an organ space infection (1.8% vs. 4.2%, P = 0.044) and to have a superficial SSI (2.6% vs. 7.6%, P = 0.001). Patients receiving bowel prep with oral antibiotics were also less likely to have a prolonged ileus (3.9% vs. 8.6%, P = 0.011) and had similar rates of C. difficile colitis (1.3% vs. 1.8%, P = 0.58).

CONCLUSIONS

Most patients in Michigan receive mechanical bowel preparation prior to elective colectomy. Oral antibiotics may reduce the incidence of SSI.

Implementing a standard protocol to decrease the incidence of surgical site infections in rectal cancer surgery

PURPOSE

To evaluate the effectiveness of our surgical site infection (SSI) preventive strategies for rectal cancer patients.

METHODS

We compared the incidences and risk factors for SSI before (1990-1999) and after the implementation of our SSI prevention policies (2002-2006). A total of 250 patients who underwent surgery for rectal cancer were enrolled in this study. Peripheral venous blood samples were obtained perioperatively to measure the circulating pro- and anti-inflammatory cytokines.

RESULTS

The incidence of SSI was significantly lower after the introduction of SSI prevention policies [SPP(+)] than before [SPP(-)], at 13.1% vs 32.0%, respectively (P = 0.0004). Even with the infection control programs, abdominoperineal resection (APR) was an independent factor predictor of SSI after rectal cancer surgery. The consumption of postoperative interleukin (IL)-6 soluble receptor was much higher in the APR patients than in the non-APR patients. The exaggeration of postoperative IL-6 response was more pronounced in the APR patients in the SPP(+) group than in those in the SPP(-) group, although preoperative chemotherapy and/or radiotherapy might have influenced the inflammatory response.

CONCLUSIONS

These findings suggest that the introduction of SPP helped reduce the incidence of SSI, especially in the non-APR patients.

Is there a current role for preoperative non-absorbable oral antimicrobial agents for prophylaxis of infection after colorectal surgery?

BACKGROUND

In numerous scientific studies, oral antibiotic bowel preparation has reduced surgical site infections in patients undergoing colorectal surgery. The historical evolution of antibiotic bowel preparation is presented with a review of the scientific basis of its effectiveness.

METHODS

Review of the pertinent English language literature.

RESULTS

Successful oral antibiotic bowel preparation requires effective mechanical preparation. The progressive shift of preoperative preparation to the outpatient setting has led to a reduction in the use of oral antibiotics. Such preparation, however, continues to be effective although in current surgical practice is often augmented with perioperative, parenteral antimicrobials.

CONCLUSION

Oral antibiotic bowel preparation has a role in the prevention of surgical site infection in the patient undergoing colorectal surgery.

Elective colon and rectal surgery differ in risk factors for wound infection: results of prospective surveillance

OBJECTIVE

The objective of this study was to clarify the incidence and risk factors for developing incisional surgical site infection (SSI) in both elective colon and rectal surgery.

SUMMARY BACKGROUND DATA

SSI is a frequent complication after elective colorectal resection. The National Nosocomial Infection Surveillance system surveys all colorectal surgeries together, without differentiating the type of colorectal surgery performed. However, rectal surgery may have a higher risk for SSI, and identifying risk factors that are more specific to each procedure would be more predictive.

METHODS

We conducted prospective SSI surveillance of all elective colorectal resections performed by a single surgeon in a single institution from November 2000 to July 2004. The data for colon and rectal surgeries were collected separately. The outcome of interest was incisional SSI. Univariate and multivariate analyses were performed to determine the predictive significance of variables in each type of surgery.

RESULTS

A total of 556 colorectal resections, consisting of 339 colon and 217 rectal surgeries, were admitted to the program. The incisional SSI rates in colon and rectal surgeries were 9.4% and 18.0%, respectively (P = 0.0033). Risk factors for developing incisional SSI in colon surgery were ostomy closure (OR = 7.3) and lack of oral antibiotics (OR = 3.3), while in rectal surgery, risk factors were preoperative steroids (OR = 3.7), preoperative radiation (OR = 2.8), and ostomy creation (OR = 4.9).

CONCLUSIONS

Colon and rectal surgeries differ with regard to incidence and risk factors for developing incisional SSI. SSI surveillance for such surgeries should be performed separately, as this should lead to more efficient identification of risk factors and a reduction in SSI.

Wound infection after elective colorectal resection

INTRODUCTION

Surgical site infection (SSI) is a potentially morbid and costly complication following major colorectal resection. In recent years, there has been growing attention placed on the accurate identification and monitoring of such surgical complications and their costs, measured in terms of increased morbidity to patients and increased financial costs to society. We hypothesize that incisional SSIs following elective colorectal resection are more frequent than is generally reported in the literature, that they can be predicated by measurable perioperative factors, and that they carry substantial morbidity and cost.

METHODS

Over a 2-year period at a university hospital, data on all elective colorectal resections performed by a single surgeon were retrospectively collected. The outcome of interest was a diagnosis of incisional SSI as defined by the Center of Disease Control and Prevention. Variables associated with infection, as identified in the literature or by experts, were collected and analyzed for their association with incisional SSI development in this patient cohort. Multivariate analysis by stepwise logistic regression was then performed on those variables associated with incisional SSI by univariate analysis to determine their prognostic significance. The incidence of SSI in this study was compared with the rates of incisional SSI in this patient population reported in the literature, predicted by a nationally based system monitoring nosocomial infection, and described in a prospectively acquired intradepartmental surgical infection data base at our institution.

RESULTS

One hundred seventy-six patients undergoing elective colorectal resection were identified for evaluation. The mean patient age was 62 +/- 1.2 years, and 54% were men. Preoperative diagnoses included colorectal cancer (57%), inflammatory bowel disease (20%), diverticulitis (10%), and benign polyp disease (5%). SSIs were identified in 45 patients (26%). Twenty-two (49%) SSIs were detected in the outpatient setting following discharge. Of all preoperative and perioperative variables measured, increasing patient body mass index and intraoperative hypotension independently predicted incisional SSI. Although we could not measure statistically increased length of hospital stay associated with SSI, a representative population of patients with SSI accumulated a mean of $6200/patient of home health expenses related to wound care. Our rates of SSI were substantially higher than that reported generally in the literature, predicted by the National Nosocomial Infection System, or described by our own institutional surgical infection data base.

CONCLUSIONS

The incidence of incisional SSI in patients undergoing elective colorectal resection in our cohort was substantially higher than generally reported in the literature, the NNIS or predicted by an institutional surgical infection complication registry. Although some of these differences may be attributable to patient population differences, we believe these discrepancies highlight the potential limitations of systematic outcomes measurement tools which are independent of the primary clinical care team. Accurate surgical complication documentation by the primary clinical team is critical to identify the true frequency and etiology of surgical complications such as incisional SSI, to rationally approach their reduction and decrease their associated costs to patients and the health care system.

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.

Risk factors for surgical site infection after elective resection of the colon and rectum: a single-center prospective study of 2,809 consecutive patients

OBJECTIVE

To identify the risk factors for surgical site infection (SSI) in patients undergoing elective resection of the colon and rectum.

SUMMARY BACKGROUND DATA

SSI causes a substantial number of deaths and complications. Determining risk factors for SSI may provide information on reducing complications and improving outcome.

METHODS

The authors performed a prospective study of 2,809 consecutive patients undergoing elective colorectal resection via laparotomy between February 1995 and December 1998 at a single institution. The outcome of interest was SSI, which was classified as being incisional or organ/space with or without clinical leakage. A likelihood ratio forward regression model was used to assess the independent association of variables with SSIs.

RESULTS

The overall SSI, incisional SSI, and organ/space SSI with and without clinical anastomotic leakage rates were 4.7%, 3%, 2%, and 0.8%, respectively. Risk factors for overall SSI were American Society of Anesthesiology (ASA) score 2 or 3 (odd ratio [OR] = 1.7), male gender (OR = 1.5), surgeons (OR = 1.3-3.3), types of operation (OR = 0.3-2.1), creation of ostomy (OR = 2.1), contaminated wound (OR = 2.9), use of drainage (OR = 1.6), and intra- or postoperative blood transfusion (1-3 units, OR = 5.3; >/=4 units, OR = 6.2). However, SSIs at specific sites differed from each other with respect to the risk factors. Among a variety of risk factors, only blood transfusion was consistently associated with a risk of SSI at any specific site.

CONCLUSIONS

In addition to ASA score and surgical wound class, blood transfusion, creation of ostomy, types of operation, use of drainage, sex, and surgeons were important in predicting SSIs after elective colorectal resection.

Prophylactic Antibiotics in Surgery and Surgical Wound Infections

Wound infection remains a considerable cause of morbidity and mortality among surgical patients, despite the relative success of prophylactic antibiotics. In modern efforts to control healthcare costs while improving the quality of patient care, we must not overlook the basic principles of wound infections and their appropriate treatment. Predisposing factors for the development of surgical wound infection include the creation of a surgical wound, the presence of bacteria, and a susceptible host. The selection of an appropriate antimicrobial drug depends on the identification of the most likely pathogens associated with a given procedure, as well as the expected antibiotic susceptibility of those pathogens. Ideally, a prophylactic antibiotic should achieve high peak tissue concentration at the site of the wound before the first incision and should be maintained until the time of closure. Currently, the administration of prophylactic antibiotics is indicated for contaminated and clean-contaminated wounds. Despite the proven effectiveness of antibiotic prophylaxis, many researchers would argue that contemporary dosing regimens should be reevaluated. The debates concerning the dosage and timing of ideal prophylactic administration are likely to continue.

Prophylactic and therapeutic use of antibiotics in pelvic surgery

The abiding principles of antibiotic use in the surgical patient vary in the complicated pelvic surgery setting only in that some microbes likely to be encountered warrant minor variation in drug choice. Very early antibiotic administration, relatively large doses, and prompt association when the reason for therapy has been accomplished, are the keystones for treatment. Tissue levels of antimicrobial activity are the uniform therapeutic goal. We also prefer consistent selection of drugs known to be safe and believe that continuous infusion may enhance the overall protective effect. Preservation of normal host defenses enhances the action of all antibiotics.

[Antibiotic prophylaxis in colorectal surgery]

In elective colorectal surgery, the benefit of preoperative antibiotic prophylaxis is well established, with a reduction in wound infection rate to less than 10%. The antimicrobial agent used has to be active against aerobic and anaerobic pathogens such as Escheria coli and Bacteriodes fragilis. The efficacy of three schemes of administration: oral and/or parenteral prophylaxis associated with a mechanical preparation, has been demonstrated. Oral antibiotic administration is current practice in USA; the most widely used oral regimen is the combination of erythromycin and neomycin given the day before surgery. Parenteral prophylaxis with a cephalosporin active against Bacteriodes fragilis such as cefoxitin and cefotetan, is preferred in Europe. The issue of whether a systemic prophylaxis should be added to the oral regimen or not has not yet been resolved. However it seems that the association should be proposed in various situations: patients with a high risk factors score (rectal resection and operations lasting more than three hours), patients with incomplete mechanical preparation, delay of the onset of surgery after the last oral dose.

Preoperative bowel preparation. A survey of colon and rectal surgeons

A survey of 500 clinically active, board-certified colon and rectal surgeons in the United States and Canada was conducted to obtain data regarding current methods of bowel preparation for elective colorectal surgery. A review of recent publications on preoperative bowel preparation was used to compare the current literature recommendations with the actual practice among the group surveyed. Responses were received from 352 of 500 colorectal surgeons to whom questionnaires were sent (70 percent response rate). All respondents used a mechanical preparation and some form of antibiotics. The favorite antibiotic regimen was oral antimicrobials combined with systemic antibiotics (88 percent). Concomitant administration of oral neomycin-erythromycin base and a systemic second generation cephalosporin active against both anaerobic and aerobic colonic bacteria, together with oral polyethelene glycol electrolyte mechanical colonic cleansing, was the most popular method of preoperative bowel preparation (58 percent). The second most frequent method of mechanical bowel cleansing consisted of conventional enemas, dietary restrictions, and cathartic preparations (36 percent). Mannitol solution (5 percent), and whole-gut irrigation per nasogastric tube (1 percent) were the least popular methods of mechanical bowel cleansing. The literature supports the current methods of preoperative bowel preparation used by the vast majority of surgeons surveyed.

Suppression of colonic microflora by cefoperazone and evaluation of the drug as potential prophylaxis in bowel surgery

We evaluated the activity of cefoperazone (CPZ) on the intestinal flora in terms of its use as a single prophylactic drug in colon surgery. Twenty-four healthy male volunteers between the ages of 20 and 40 were assigned to receive either CPZ, oral neomycin-erythromycin, or no antibiotics. A mechanical bowel preparation, Golytely, was also given to each of the subjects. With intravenous CPZ, antibiotic levels in the stool ranged from less than 2 to 649 micrograms/ml and the total fecal bacterial counts dropped 3 to 4 log10 CFU/g. Higher levels of CPZ were detected in the stools when an oral dose was added, 1,446 to 5,445 micrograms/ml, and the bacterial counts were reduced maximally 4 to 6 log10 CFU/g. The combination of the oral and intravenous doses produced suppression of the microflora and high levels in blood, all with a single antibiotic.

Single-dose cefotetan vs. multiple-dose cefoxitin--antimicrobial prophylaxis in colorectal surgery. Results of a prospective, multicenter, randomized study

This multicenter, prospective, randomized trial of short-term antimicrobial prophylaxis in colorectal surgery was designed to compare the efficacy of a single dose of cefotetan vs. multiple doses of cefoxitin. Of the 403 evaluable patients, 206 received cefoxitin (1 gm intravenously at the beginning of surgery and after 3, 6, and 12 hours, group A) and 197 cefotetan (2 gm intravenously at the beginning of surgery, group B). The two groups of patients were similar in respect to age, sex, obesity, preoperative weight loss, diabetes, type of disease, type, and mean duration of surgery. The abdominal wound infection rate was 11.2 percent in group A and 9.1 percent in group B (difference not significant). The number of patients with infections at nonsurgical sites (respiratory and urinary tract, phlebitis, and septicemia) was significantly greater in group A than in group B (17 vs. 9.1 percent, P less than .05). The mean postoperative hospital stay was similar in both the cefoxitin and cefotetan groups (15.1 vs. 15.9 days). Both regimens were inadequate in preventing infections in the presence of severe contamination of the operative field.

Cefoxitin for one day vs. ampicillin and metronidazole for three days in elective colorectal surgery. A prospective, randomized, multicenter study

In a multicenter study the prophylactic efficacy of two antibiotic regimens was tested against postoperative septic complications following elective colorectal surgery. The study was conducted in a prospective block-randomized design. Patients were preoperatively allocated to either ampicillin, 1 gm, four times daily, and metronidazole, 0.5 gm, three times daily, for 72 hours, or to cefoxitin, 2 gm, given three times in a period of 10 hours. Both regimens were initiated immediately before surgery. Forty-five patients were withdrawn from the study after randomization. Three hundred fifty two patients (175 receiving ampicillin and metronidazole and 177 receiving cefoxitin) completed the study and were followed for one month postoperatively. The frequency of septic and nonseptic complications was not statistically significant different between the two regimens. About one third of all septic complications appeared more than two weeks after surgery. It is concluded that short-term treatment with cefoxitin is at least as efficient as a three-day treatment with ampicillin and metronidazole.