Single-dose cefotetan versus multiple-dose cefoxitin as prophylaxis in colorectal surgery

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

Background

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

Objectives

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

Methods

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

Results

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

Conclusion

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

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.

•

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

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.

Randomized controlled trial comparing subcuticular absorbable suture with conventional interrupted suture for wound closure at elective operation of colon cancer

BACKGROUND

Subcuticular closure provides a superior cosmetic result in clean wounds. The aim of this work was to investigate the safety in terms of postoperative infection and cosmetic effectiveness of subcuticular wound closure after elective colon cancer surgery in clean-contaminated wounds.

METHODS

Patients who underwent elective resection of colon cancer were randomized to interrupted subcuticular and interrupted transdermal suture groups. The large bowel was prepared by mechanical washout with polyethylene glycol. All patients received metronidazole and kanamycin orally and flomoxef sodium once parenterally for antimicrobial prophylaxis. The primary end point was the incidence of incisional surgical-site infections within 30 days after operation. We assessed noninferiority of subcuticular suture within a margin of 10%. Analysis was by intent-to-treat. Secondary objectives include comparison of wound closure time, comfort, and cosmesis of the scar and satisfaction of patients. This study was registered with UMIN-CTR, UMIN000003005.

RESULTS

A total of 293 patients were randomized to the two groups. Incisional surgical-site infection rates were 11.0% (90% confidence interval 7.0-16.3%) for both groups. The relative risk of subcuticular suture was 1.00 (0.58-1.73, one-tail P = .57). Interrupted subcuticular suture was noninferior to interrupted transdermal suture (P = .0088). Throughout 6 months after operation, patients expressed a significant preference for the subcuticular suture technique, noting rapid relief from pain, decreased vascularity, and smaller width, although the procedure took twice as long.

CONCLUSION

Subcuticular suture did not increase the incidence of wound complications in elective colon cancer operation. Patients preferred a technique of interrupted subcuticular closure, citing better cosmetic results, and less pain.

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.

Surgical antibiotic practices among pediatric urologists in the United States

PURPOSE

We hypothesized that there are practice variations in the use of surgical antibiotics by pediatric urologists in the United States.

MATERIALS AND METHODS

A 31-question online survey was distributed to members of the Society of Pediatric Urology. The questionnaire examined physician preferences for surgical antibiotic use, including indications, antibiotic selection, timing of administration, and duration.

RESULTS

189 pediatric urologists responded to the survey. >85% of responders give antibiotics before open pyeloplasty, after hypospadias repair (when a urethral catheter is left in place), or perioperative or postoperative antibiotics for open neoureterocystostomy or bladder reconstructive surgery. >90% of responders do not give postoperative antibiotics to children who have undergone circumcisions, simple chordee repairs, herniorrhapies, or hydrocelectomies. For all other open, laparoscopic, and endoscopic operations, use of antibiotics varied significantly. Diverse opinions exist regarding antibiotic use, including the importance of costs, potential adverse reactions, reduction in infection risk, and antibiotic resistance. There are major differences in gentamicin dosing and timing of administration of perioperative antibiotics.

CONCLUSIONS

Perioperative and postoperative antibiotics are widely used by pediatric urologists. However, there is significant practice variation in surgical antibiotic administration with regards to most areas of pediatric urology, in particular laparoscopic, endoscopic and hypospadias surgery.

Wound infection after colostomy closure for imperforate anus in children: utility of preoperative oral antibiotics

BACKGROUND/PURPOSE

There is little published data on the efficacy of surgical infection prophylaxis in children. The purpose of this study was to assess wound infection rate in children undergoing colostomy closure for imperforate anus and evaluate the impact of bowel preparation and antibiotics.

METHODS

Children younger than 18 years with imperforate anus who had a colostomy closure between January 1996 and December 2007 were identified. Data collected included demographics, bowel preparation, antibiotics, operative details, and postoperative infections. Comparison of mechanical bowel preparation and intravenous antibiotics with and without oral antibiotics was compared using chi(2) tests. Significance was defined as P < .05.

RESULTS

A total of 118 patients were identified. Primary skin closure was done in 97%. Mechanical bowel preparation was used in 93%, intravenous antibiotics in 97%, and oral preoperative antibiotics in 52%. Wound infections occurred in 14% (n = 17). The addition of oral antibiotics to the standard regimen of mechanical bowel preparation with intravenous antibiotics did not alter infection rate (13% versus 17%, P = .64).

CONCLUSION

Wound infection in children undergoing elective colostomy closure for imperforate anus was 14%. Infection rate was not affected by use of oral antibiotics. Future studies may allow specific guideline development for infection prophylaxis in pediatric patients.

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.

Antimicrobial prophylaxis in colorectal surgery: focus on ertapenem

Despite improvement in infection control measures and surgical practice, surgical site infections (SSIs) remain a major cause of morbidity and mortality. In colorectal surgery, perioperative administration of a suitable antimicrobial regimen that covers both anaerobic and aerobic bacteria is universally accepted. In a prospective, double-blind, randomized study ertapenem was recently found to be more effective than cefotetan, a parenteral cephalosporin so broadly used as to be considered as gold standard in the prevention of SSIs following colorectal surgery. In this adequate and well controlled study, the superiority of ertapenem over cefotetan was clearly demonstrated from the clinical and bacteriological points of view. However, data that directly compares ertapenem with other antimicrobial regimen effective in preventing SSIs following colorectal surgery are lacking; furthermore, the possible risk of promotion of carbapenem resistance associated with widespread use of ertapenem prophylaxis as well as the ertapenem effects on the intestinal gut flora are of concern. Further comparative studies of ertapenem versus other widely used prophylactic regimens for colorectal surgery in patients submitted to mechanical bowel preparation versus no preparation as well as further research on adverse events of antibiotic prophylaxis, including emergence of resistance and Clostridium difficile infection, seem warranted.

Infection after elective colorectal surgery: bacteriological analysis of failures in a randomized trial of cefotetan vs. ertapenem prophylaxis

BACKGROUND

A randomized study comparing single-dose cefotetan and ertapenem prophylaxis for elective colorectal surgery in 1,002 patients found ertapenem to be significantly more effective (p < 0.001). Failures of prophylaxis were thought to involve organisms resistant to both antimicrobial agents, isolated most often from deep or superficial incision sites.

METHODS

Further testing and analysis of the microbial data was performed. Susceptibility results were correlated with the clinical outcomes reported previously.

RESULTS

Of the 216 aerobes tested, 62.6% were resistant to cefotetan and 44% to ertapenem. Enterococci and methicillin-resistant Staphylococcus epidermidis were the aerobes recovered most frequently, and Bacteroides thetaiotaomicron, Clostridium innocuum, and Eubacterium lentum were the most frequent anaerobes. Enterococcus faecalis usually was associated in mixed culture with Bacteroides fragilis group species. Approximately one-half of the 158 anaerobes (50.7%), including all the species above, were resistant to cefotetan; most of these (61.4%) came from superficial incision sites. Only one anaerobe (Desulfovibrio fairfieldensis), found in a superficial incisional infection, was resistant to ertapenem, and no ertapenem-resistant enteric bacteria were recovered. In vitro resistance was associated with therapeutic failure.

CONCLUSIONS

The in vitro activity of ertapenem was superior to that of cefotetan against all anaerobic and many aerobic bacteria isolated from postoperative cultures of patients who failed prophylaxis with these agents. Our findings help to elucidate the results of the clinical trial.

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.

Risk Factors for Wound Complication in Pilonidal Sinus Procedures

BACKGROUND

Pilonidal disease is a common condition among young people. Complicated pilonidal surgical wounds are associated with considerable morbidity, including chronic sacral wound, loss of work time, and lifestyle limitation. The aim of our study is to report our experience with Karydakis procedure and explore the risk factors associated with infection and poor healing in pilonidal operation.

STUDY DESIGN

A 3-year experience of a Joint-Commission International accredited tertiary center in patients with pilonidal sinus operations is reported. We retrospectively reviewed the charts of unselected patients with pilonidal sinus who underwent excision and primary closure on elective basis in terms of wound healing, surgical site infection, and return to work. Variables predictive of surgical site infection and disruption were assessed by multiple logistic analyses.

RESULTS

From January 2004 to December 2006, 94 patients with pilonidal disease underwent excision and primary closure on elective basis. Incidence of surgical site infection was 12.8%. No recurrence was observed after median followup of 6 months, with interquartile range of 4 to 9 months. Smoking (p = 0.027) and obesity (p = 0.047) were independent risk factors for wound infections.

CONCLUSIONS

Excision and primary closure is an acceptable modality of treatment in nonobese and nonsmoker patients with pilonidal sinus disease. Infection rate in obese patients and smokers is unacceptably high, and active preoperative weight loss and smoking cessation or simple laid open procedure is recommended in these patients.

Ertapenem versus cefotetan prophylaxis in elective colorectal surgery

BACKGROUND

Ertapenem, a long-acting carbapenem, may be an alternative to the recommended prophylactic antibiotic cefotetan.

METHODS

In this randomized, double-blind trial, we assessed the efficacy and safety of antibiotic prophylaxis with ertapenem, as compared with cefotetan, in patients undergoing elective colorectal surgery. A successful outcome was defined as the absence of surgical-site infection, anastomotic leakage, or antibiotic use 4 weeks postoperatively. All adverse events were collected until 14 days after the administration of antibiotic prophylaxis.

RESULTS

Of the 1002 patients randomly assigned to study groups, 901 (451 in the ertapenem group and 450 in the cefotetan group) qualified for the modified intention-to-treat analysis, and 672 (338 in the ertapenem group and 334 in the cefotetan group) were included in the per-protocol analysis. After adjustment for strata, in the modified intention-to-treat analysis, the rate of overall prophylactic failure was 40.2% in the ertapenem group and 50.9% in the cefotetan group (absolute difference, -10.7%; 95% confidence interval [CI], -17.1 to -4.2); in the per-protocol analysis, the failure rate was 28.0% in the ertapenem group and 42.8% in the cefotetan group (absolute difference, -14.8%; 95% CI, -21.9 to -7.5). Both analyses fulfilled statistical criteria for the superiority of ertapenem. In the modified intention-to-treat analysis, the most common reason for failure of prophylaxis in both groups was surgical-site infection: 17.1% in the ertapenem group and 26.2% in the cefotetan group (absolute difference, -9.1; 95% CI, -14.4 to -3.7). In the treated population, the overall incidence of Clostridium difficile infection was 1.7% in the ertapenem group and 0.6% in the cefotetan group (P=0.22).

CONCLUSIONS

Ertapenem is more effective than cefotetan in the prevention of surgical-site infection in patients undergoing elective colorectal surgery but may be associated with an increase in C. difficile infection. (ClinicalTrials.gov number, NCT00090272 [ClinicalTrials.gov].).

Mechanical and Antibacterial Bowel Preparation in Colon and Rectal Surgery

Colorectal surgery performed prior to 1970 was fraught with postoperative infectious complications which occurred in more than 30-50% of all operations. Diversion of the fecal stream appeared mandatory when operating on an urgent or emergent basis, thereby requiring the performance of multiple, staged operations instead of a single surgery encompassing resection and primary anastomosis as is performed commonly today. Multiple studies conducted in the early 1970s determined that anaerobic colonic microflora were causative agents in postoperative infections in colon and rectal surgery, and these studies initiated the development of effective oral preoperative antibiotic prophylaxis in combination with preoperative mechanical bowel preparation. This dual-tier regimen significantly reduced the incidence of postoperative infectious complications, thus allowing most uncomplicated colon and rectal surgeries to be performed in a single stage without the need for the diversion of the fecal stream and multiple operations. Therefore, a preoperative mechanical and antibacterial bowel regimen serves as the cornerstone of modern elective colorectal surgery, and these regimens now comprise three therapeutic directives. The first step is preoperative mechanical cleansing of the bowel, which is then followed by preoperative oral antibiotic prophylaxis. Finally, perioperative parenteral antibiotics directed against aerobic and anaerobic colonic microflora are utilized.

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.

The role of beta-lactam antimicrobials as single agents in treatment of intra-abdominal infection

Broad-spectrum beta-lactam antibiotics have several advantages in the treatment of intra-abdominal infections. These agents are effective against gram-negative rods and anaerobes, reach therapeutic levels rapidly after parenteral administration, and, in the absence of penicillin allergy, generally exhibit low toxicity. The second-generation cephalosporins (e.g., cefoxitin, cefotetan) are used widely in surgical prophylaxis, trauma, and treatment of mild-to-moderate community-acquired infections, but limitations in their spectra and microbial resistance restrict their utility in more serious infections. Extended-spectrum penicillin/beta-lactamase-inhibitor combinations are effective in the treatment of intra-abdominal infections and include enterococci in their spectrum. Gram-negative aerobe resistance has developed to ampicillin/sulbactam. Piperacillin/tazobactam, a ureidopenicillin with increased gram-negative coverage and enhanced antipseudomonal activity, has proved to be effective in clinical trial therapy for intra-abdominal infections. The very broad spectrum carbapenems--imipenem/cilastatin and meropenem--are effective for serious infections or resistant organisms and are often used in the intensive care unit or for nosocomial intra-abdominal infection. These classes of beta-lactams comprise a range of antimicrobials that can be targeted effectively as single agents to both prevention and treatment of intra-abdominal infection.

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.

Double-blind comparison of single-dose alatrofloxacin and cefotetan as prophylaxis of infection following elective colorectal surgery. Trovafloxacin Surgical Group

BACKGROUND

Alatrofloxacin, the prodrug of trovafloxacin, is a novel fluoroquinolone antimicrobial agent with a broad spectrum, including activity against gram-positive and gram-negative aerobes and anaerobes. Its pharmacokinetic properties (long half-life, excellent tissue distribution, and good safety profile) suggest a role in surgical prophylaxis. This prospective, multicenter, double-blind trial compared alatrofloxacin with cefotetan, an approved drug for surgical prophylaxis, in reducing postoperative infections.

METHODS

The efficacy and safety of a single 200-mg intravenous dose of alatrofloxacin were compared to a single 2-g intravenous dose of cefotetan in 492 patients undergoing elective colorectal surgery. The efficacy of alatrofloxacin as a prophylaxis for wound, intra-abdominal, or remote-site postoperative infectious complications was compared with cefotetan in 317 clinically evaluable patients; 161 received alatrofloxacin and 156 received cefotetan. The patients were monitored for infections and safety for 30 days postoperatively.

RESULTS

No statistically significant between-treatment difference was detected in successful clinical response rates at the end of the study (72% for each group). The incidence of primary wound infections at the time of hospital discharge was also similar: 21% in patients treated with alatrofloxacin and 18% in those treated with cefotetan. Safety, established by the incidence of adverse events, did not differ statistically between the groups.

CONCLUSIONS

A single intravenous dose of alatrofloxacin given within 4 hours prior to surgery was as effective as an intravenous dose of cefotetan in the prevention of postoperative infectious complications in patients undergoing elective colorectal surgery. The safety profiles of the two medications were similar.

Single- versus multiple-dose antimicrobial prophylaxis for major surgery: a systematic review

BACKGROUND

Single-dose antimicrobial prophylaxis for major surgery is a widely accepted principle; recommendations have been based on laboratory studies and numerous clinical trials published in the last 25 years. In practice, single-dose prophylaxis has not been universally accepted and multiple-dose regimens are still used in some centres. Moreover, the principle has recently been challenged by the results of an Australian study of vascular surgery. The aim of this current systematic review is to determine the overall efficacy of single versus multiple-dose antimicrobial prophylaxis for major surgery and across surgical disciplines.

METHODS

Relevant studies were identified in the medical literature using the MEDLINE database and other search strategies. Trials included in the review were prospective and randomized, had the same antimicrobial in each treatment arm and were published in English. Rates of postoperative surgical site infections (SSI) were extracted, 2 x 2 tables prepared and odds ratios (OR) [with 95% confidence intervals (95% CI)] calculated. Data were then combined using fixed and random effects models to provide an overall figure. In this context, a high value for the combined OR, with 95% CI > 1.0, indicates superiority of multiple-dose regimens and a low OR, with 95% CI < 1.0, suggests the opposite. A combined OR close to 1.0, with narrow 95% CI straddling 1.0, indicates no clear advantage of one regimen over another. Further subgroup analyses were also performed.

RESULTS

Combined OR by both fixed (1.06, 95% CI, 0.89-1.25) and random effects (1.04, 95% CI, 0.86-1.25) models indicated no clear advantage of either single or multiple-dose regimens in preventing SSI. Likewise, subgroup analysis showed no statistically significant differences associated with type of antimicrobial used (beta-lactam vs other), blinded wound assessment, length of the multiple-dose arm (> 24 h vs 24 h or less) or type of surgery (obstetric and gynaecological vs other).

CONCLUSIONS

Continued use of single-dose antimicrobial prophylaxis for major surgery is recommended. Further studies are required, especially in previously neglected surgical disciplines.

A double-blind, randomized study of three antimicrobial regimens in the prevention of infections after elective colorectal surgery

The objective of this study was to assess the prophylactic efficacy of cefoxitin, ceftizoxime, and metronidazole-gentamicin in colorectal surgery. A double-blind, randomized prospective clinical trial design was used in a Canadian tertiary care teaching hospital. Patients were randomized to one of three treatment groups and received three doses of a study drug (30 min preoperative and 2 postoperative doses at 12 and 24 h). Cefoxitin and ceftizoxime were given as 1000-mg doses. Metronidazole-gentamicin was given as 500 mg of metronidazole plus 120 mg of gentamicin in a minibag. High-risk patients (bowel ischemia, diabetic, current steroid use, etc.) received 10 postoperative doses. Patients with infections, prior antibiotics, or study drug allergies were excluded. Over 30 months, 153 patients were enrolled. Thirty-one patients were excluded for protocol violations. Of the 122 evaluable patients (38 ceftizoxime, 45 metronidazole-gentamicin, 39 cefoxitin), there was no difference across groups regarding sex, age, weight, preoperative Apache II score, and prior history of bowel surgery. Groups were equivalent regarding surgeon, nursing unit, high-risk status (six ceftizoxime, seven metronidazole-gentamicin, seven cefoxitin), bowel preparation, and procedure (including blood loss, drains, organ injury, intraoperative complications). Clinically significant infection requiring systemic antibiotics (7-day hospital and 30-day follow-up) was identified in 0% of ceftizoxime, 15% of metronidazole-gentamicin, and 26% of cefoxitin receiving patients (p = 0.005). Mean ASEPSIS scores for each group were 2.3 (range 0-15) for ceftizoxime, 9.2 (range 0-45) for metronidazole-gentamicin, and 10.4 (range 0-75) for cefoxitin (p = 0.01). Ceftizoxime patients tended to have a shorter total hospital stay (12.2 days versus 19.7 days for cefoxitin versus 13.9 days for metronidazole-gentamicin; p = 0.04), although the procedure to discharge interval was not significantly different (p = 0.09). There was no difference in clinical outcome according to risk status. Anaerobic bacteria were observed more commonly in the ceftizoxime and cefoxitin groups, whereas enteric Gram-negative aerobes were observed most often in the metronidazole-gentamicin group. The study regimens were generally well tolerated. Drug costs were equivalent between ceftizoxime and cefoxitin and lowest with the metronidazole-gentamicin regimen. Ceftizoxime appears to be more effective for the prevention of infection in colorectal surgery than either cefoxitin or metronidazole-gentamicin in the dosage regimens studied.

Laparoscopic-assisted sigmoid colectomy and low anterior resection

Laparoscopic-assisted sigmoid colectomy or low anterior resection was undertaken in 30 selected patients. The median age was 51 (range, 30-85) years. Eight patients had previous abdominal surgery: four hysterectomies, two appendectomies, and two cholecystectomies. There was no mortality. Complications occurred in three patients. One patient developed a wound infection, there was one iliac artery injury, and one postoperative bleed, which did not require transfusion. Eighteen patients were operated on for primary cancer of the colon and 12 patients for benign disease. Technical aspects are described in detail. The average hospital stay was four days with most patients receiving oral analgesics by the second postoperative day. Laparoscopic colon resection can be an alternative to open surgery.

[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.

Single-dose amoxycillin-clavulanic acid vs. cefotetan for prophylaxis in elective colorectal surgery: a multicentre, prospective, randomized study. The PRODIGE Group

A prospective, multicentre, randomized trial was carried out in 19 hospitals in order to compare the efficacy of amoxycillin-clavulanic acid with cefotetan as antibiotic prophylaxis in patients undergoing elective colorectal surgery. Since the main purpose of the study was to demonstrate equivalence between the two regimens, the protocol planned the inclusion of 200 patients. Eligible patients were randomly assigned to receive either amoxycillin-clavulanic acid (2.2 g) or cefotetan (2 g) in a single infusion on the induction of anaesthesia. Failure of prophylaxis was defined as occurrence of infection of intestinal origin, either minor (wound cellulitis) or major (abscess, peritonitis, septicaemia) within the 30-day postoperative period. Among 221 randomized patients, 208 (105 amoxycillin-clavulanic acid, 103 cefotetan) aged 66 +/- 12 years (mean +/- SD) were evaluated while 13 were withdrawn. Colorectal cancer was the indication for surgery in 73% of cases. Eleven (10 +/- 6%, 95% confidence interval) and 13 (13 +/- 7%) failures were observed in the amoxycillin-clavulanic acid and cefotetan groups (P = 0.63 chi-square test) respectively. Most infections occurred before the 10th postoperative day (8% failures at this time, estimated by the Kaplan-Meier method). The results of the trial demonstrate that amoxycillin-clavulanic acid and cefotetan have similar efficacy when used for prophylaxis of infection after elective colorectal surgery.

Single dose imipenem-cilastatin compared with three doses of cefuroxime and metronidazole as prophylaxis in elective colorectal surgery: a prospective randomized study

A prospective randomized study was performed with 61 patients undergoing elective surgery for colorectal cancer, to evaluate the prophylactic effect of two different parenteral antibiotic regimens. All patients were randomly allocated into two groups, comparable in age, sex, nutritional status and operative procedures. The patients in Group A (n. 31) received 1 g i.v. of imipenem-cilastatin at induction of anesthesia. Patients in Group B (n. 30) were given cefuroxime (1.5 g i.v.) plus metronidazole (0.5 g i.v.) at the time of anesthesia and two other administrations of the combined antibiotics (cefuroxime 0.75 g plus metronidazole 0.5 g i.v.) every 8 hours. The severity of sepsis was evaluated according to the scoring system proposed by Elebute and Stoner. No significant differences were found in terms of the rate of surgical infections: 9% in Group A and 16% in Group B. Infections not of surgical origin were found only in Group B (10.4%). These data suggest that a single dose of intravenous imipenem-cilastatin appears to be as effective as three doses of cefuroxime and metronidazole as prophylaxis against infection in elective colorectal surgery.

A comparative evaluation of the safety and efficacy of cefotetan and cefoxitin in surgical prophylaxis

Safety and efficacy were evaluated and compared retrospectively in 77 patients who received cefotetan (CTN) and 51 patients who received cefoxitin (CFX) for surgical prophylaxis. Both groups were similar with respect to age and gender. Surgical procedures were similar between groups (e.g., obstetric/gynecologic, renal transplant, colon, exploratory laparotomy, gastroduodenal, hernia repair). Postoperative infectious complications were more common in the CTN group (11.6 percent [9/77]) than in the CFX (7.8 percent [4/51]) group; however, this difference was not statistically significant. A higher incidence of wound infections was noted in the CTN group (5.2 percent [4/77]) than in the CFX group (2.0 percent [1/51]); this difference was also not significant. Patients receiving immunosuppressive therapy were more likely to develop infectious complications when CTN was used for prophylaxis (p = 0.0001). Clinically significant blood loss was not noted during surgery. Elevations in prothrombin times (greater than 1 sec) occurred in 27.3 percent (3/11) of CTN and 11.1 percent (1/9) of CFX patients (not significant). Except for the small subset of patients receiving concomitant immunosuppressive therapy, CTN appeared to be as safe and effective as CFX when used for surgical prophylaxis. Although not statistically significant, the increased incidence of wound infections in the CTN-treated patients requires further study in a prospective randomized comparison.

A survey of antimicrobial prophylaxis in elective colorectal surgery in New Zealand

In 1988 a survey of New Zealand general surgeons was conducted, by post, on the subject of routine antimicrobial prophylaxis for elective colorectal surgery. Surgeons who gave routine prophylaxis were asked for details of their regimens; those who did not were asked for their reasons. One hundred and seventy-five questionnaires were distributed and 167 were returned. Of these, 124 came from surgeons with a colorectal practice, and 118 of the 124 surgeons satisfactorily completed the questionnaire. Routine antimicrobial prophylaxis was given by 96.6% (114 of 118). Of the 114 surgeons prescribing prophylaxis, one antimicrobial agent was used by 36.8%, two were employed by 53.5% and three or five were used by the remainder. The most commonly used (74.6%) antimicrobial agents were cephalosporins which were prescribed, alone or in combination with a nitroimidazole. The most frequent duration (46.4%) of antimicrobial administration was a combination of both the peri- and postoperative periods. When antimicrobial spectrum, route and duration of administration were all taken into account, 49.1% (56 of 114) were considered to give satisfactory regimens. Excessively protracted administration was the most frequent reason for unsatisfactory classification. The results of this survey demonstrate serious deficiencies in the practice of antimicrobial prophylaxis in elective colorectal surgery. These should be addressed through a programme of continuing education.

Cefoxitin in the prevention and treatment of infections

A review of the literature indicates that cefoxitin is an effective single-agent therapy for community-acquired intra-abdominal infections, pelvic infections, and surgical prophylaxis. Hospital-acquired intra-abdominal infections may require the addition of an aminoglycoside.

Comparison of one dose versus three doses of prophylactic antibiotics, and the influence of blood transfusion, on infectious complications in acute and elective colorectal surgery

In a randomized prospective controlled trial involving 311 patients undergoing acute or elective colorectal surgery, the efficacy and safety of two different single dose and one triple dose regimen of antibiotic prophylaxis, as well as the influence of blood transfusion on postoperative infectious complications, were studied. Postoperative infectious complications occurred in a total of 59 patients (19.0 per cent). There were no major differences between the three treatment groups. Thirty-four patients (10.9 per cent) developed abdominal wound infection, 17 patients (5.5 per cent) intra-abdominal abscess and 16 patients (5.1 per cent) anastomotic leakage. Of 202 patients (65.0 per cent) requiring blood transfusion during hospitalization 57 (28.2 per cent; 95 per cent confidence limits of 23-36 per cent) developed infectious complications, whereas two non-transfused patients (1.8 per cent; 95 per cent confidence limits of 0.2 to 6 per cent; P less than 0.001) developed infectious complications. It is concluded that one single dose of antibiotic prophylaxis in acute and elective colorectal surgery is as protective as a triple dose regimen. The development of infectious complications despite antibiotic prophylaxis is strongly related to blood transfusion.

Single dose cefotaxime plus metronidazole versus three dose cefuroxime plus metronidazole as prophylaxis against wound infection in colorectal surgery: multicentre prospective randomised study

OBJECTIVE

To establish whether a single preoperative dose of cefotaxime plus metronidazole was as effective as a standard three dose regimen of cefuroxime plus metronidazole in preventing wound infection after colorectal surgery.

DESIGN

Prospective randomised allocation to one of two prophylactic antibiotic regimens in a parallel group trial. Group sequential analyses of each 250 patients were performed.

SETTING

14 District general and teaching hospitals.

PATIENTS

1018 Adults having colorectal operations were randomised, of whom 943 were evaluated. Demographic features, conditions requiring surgery, and operative procedures were similar in the two groups. Most patients had surgery for carcinoma of the colon or rectum.

INTERVENTIONS

Group 1 received cefotaxime 1 g intravenously plus metronidazole 500 mg intravenously preoperatively. Group 2 received cefuroxime 1.5 g intravenously plus metronidazole 500 mg intravenously preoperatively, followed by cefuroxime 750 mg intravenously plus metronidazole 500 mg intravenously eight hours and 16 hours postoperatively.

MAIN OUTCOME MEASURES

Development of surgical wound infection (as evidenced by the presence of pus), death, or discharge from hospital.

RESULTS

Wound condition was scored on a five point scale on alternate days until discharge or for up to 20 days postoperatively. Wound infection rates were: group 1, 32/453 (7.1%; 95% confidence interval 4.7% to 9.4%); group 2, 33/454 (7.3%; 95% confidence interval 4.9% to 9.6%). Death rates (group 1: 26/470 (5.5%); group 2: 31/471 (6.6%], the incidence of postoperative complications, the median duration of hospital stay (12 days), and antibiotic tolerance were all similar in the two groups. Pooled data from groups 1 and 2 showed that wound infections were more frequent when minor faecal contamination had occurred at operation and when the duration of operation exceeded 90 minutes (greater than 90 min 11.2% of cases; less than 90 min 4.8%) and were associated with an extended hospital stay.

CONCLUSIONS

A single preoperative dose of cefotaxime plus metronidazole is an efficacious as a three dose regimen of cefuroxime plus metronidazole in preventing wound infection after colorectal surgery and has practical advantages in eliminating the need for postoperative antibiotics.